Power analysis of the Montana State College 2300 volt power system
by David C Johns
A THESIS Submitted to the Graduate Committee in partial fulfillment of the requirements for the
degree of Master of Science in Electrical Engineering
Montana State University
© Copyright by David C Johns (1949)
Abstract:
This paper- points out the method used, and the solutions formulated in attempting to solve the problem
of the power and voltage unbalance on the Montana State College 2300 Volt system, After months of
checking all the transformers, in the' various vaults on the campus, with Maxi-meters, the peak leads
were determined. From this, the overloads could be found and corrected by substitution of the proper
size transformers.
The three phase lines were also phased out and tagged in order that the total load on each phase could
be determined. Knowing the loading on the different phases, the unbalance was located. Dhen after
making individual analyses of all the transformer vaults, a general analysis prompted two solutions,
The first solution is designed to take care of probable future needs, whereas the second solution is a
measure to correct this unbalance immediately with a minimum of time and money, tabulated lists of
high voltage equipment are to be found at the end of the thesis. power -Analysis of the Montana State College
SBOO Volt Power System
by
BavM' c». M h n a
,
-A %B3S81$
.SubmIttM to the Graduate GoiimIttee
partial- fulfillment of the requirements
for the .degree- Of
Master of ,Solenoe- in Bleefcrioal Engineering
at
Montana, State College
Approved;
In'''Gharge df 'W3,on %drE
Boseman,- Montana
June3 1949'
,l u
-BW
- U I''i
■11/ I„1
IV 3 7 6
S & i p
2
TABLE OF CONTENTS
eO'd* t>CO
Abstract • • • • • • • • • • • • » , ,
Introduction . . . . . . . . . . .
Analyses of Individual Buildings
P r o c e d u r e ............... ..
Montana Power Sub-station • • •
Barracks, Wool Laboratory, Military Building 10
Hudson House
• • • • • • • • » » . , , , » . 1 3
Agriculture Building
• • • • ............... 13
Stock Pavilion
16
Lewis Hall
17
Montana Hall
, , . . 1 9
Physics Building
21
Hamilton Hall . . ......... . . . . » , . , . 2 4
Herrick Hall
. . . . . . . . . . .
......... 26
Quadrangle
...............
28
Girl’s Quonsets . . . , . . , , . . . . . . . 2 8
Student Union ......... • • • • • • • , . . . 3 0
H o b e r f s Hall .................................. 3 0
Hyan Laboratories ............................ . 3 3
Heating Plant ........... . . . . . ......... 37
Gymnasium • ......... . , . . . . . . , , . . 3 9
Music Building, Bridger Hall, Chemistry Annex 41
Chemistry Building . . . . . . . . . . . . . 4 3
General Analysis . . . . . . . . . .
............... 45
First Alternative
• • • • ............. . . . . . . 46
Second Alternative . . . . . . . .
.................. 53
TABLES
Table
Table
Table
Table
I Phase Loading for the First Alternative
. . 52
II Phase Loading for the Second Alternative
. 55
III Graphical Symbols for Diagrams . . . . . . 56
IV-a Transformers
. . . . , ............. . . 5 7
b Automatic Oil Circuit Breakers
. . . . . 60
c Oil Switches
. , . . . . , , , , . . , . 6 1
d Fuse Cutouts
. , . , . , . . , , , . , , 6 2
Table V High Voltage Equipment in the Vaults . . . . 63
S'934j.
ABsg?RA8%
Siis paper- ,pol^ls oul t W W t h o d Psedii: a n d the solutions
Im .attempting to solve the prohiem of the power and
Voltage UBhalanee on the Montana State College 2300 volt system,
.After menthe of Gheaklng all the t&ehsfoamere, && t h d v & M o u e
vaults on the Giaapue^ with ies;l-*m©tehs>, the peak loads,/were
determined,
From this, the overloads could he found and
eorreeted'by ■substitution of the proper size transformers#/
fhO' three phase- lines were also phased out and- tagged- In order
that the total load on each phase could he -determined*
Knowing
the; loading on the different phases^ the unhalanee was Io-Catedjt,
#hen after making individual analyses of all the transformer
vaults^- a general analysis prompted two solutions«. Ihe '-first
solution is designed to take- care of profedbie fnfu # d .hhede-i
whereas the .second solution is a 'Measure- to correct this u n ­
balance immediately with a minimum of time and money.
Tabulated lists of high voltage equipment are to he found at
the end. pf the thesis#
. . .
i
three years have shewn a ■great ehange at Montana
Mate. College*
Because ©if ■the G« I*. Btlls.'the enrollment
jumped by leap's and' bounds^ more than doubling the pre-war
enrollment#
Boweveb, the same building# wera^ln salat&ndd '
after' the nar as had* been here before the war*
increased in aig# dp Bomber*
They had not
Te house and lnstrhct this In*
creased' number of students* many temporary buildings were
erected here -and there on the campus* and- -some of the old
buildings were remodeled to W l d more students* Thin increased
:v
< .
' ■'
enrollment thus -created an increased' electrical lead*- ''I- -
Thp new buildings' W r e erected hastily* and the 'eWetrloal
loads-of these/new buildings were connected onto the phases^,
of the. main distribution lines* a t 'random
Additional trans­
formers: >#re- placed in different buildings*- but no attention
was■placed upon the loading on the different phases*'' ■
Now* after three years of expansion* the high voltage '
system- on the campus is as shown in figure I*.
Because of the
unsystematic, manner in which the additional load® have been
placed -on the phases* the voltages around the campus are
greatly -unbalanced-*
In the Syan laboratories.*, to cite an
example* there has been as much as SG volts difference in the
three phase circuit#.
The Physics department has also Comments
ed bn the unbalance of the voltage*
They state that this
i Ry on
Sluc/esi]
S IX T H
AVEHUE
Union
MONTANA STATE COLLEGE
Z 3 0 0 VOL T SYSTEM
—
Unde^g^ounJCciUg
■ E jOnsfonmen s
—
OveUeac/ [_ines
S c o / e — / "•=ZZCO f/.
figure. /
GiiSHgylng yntoailsiics oi VG^tisgBS- te&lE0,S' iis
irapossltoi© t;o
perform some electronic■experimenfa which employ a GeigerCounter.^ ',
. , _ . ^ ■t
-
5ihe problem is to check this,system, determine Jpat %
#iere the %mbala&6e Occhre^ md. tc offer a solmtloh*
•In the flgarea to .follow, ,both the peak Chrreht and the
rated- current is indicated* , The primary voltage on the
tranaforme-r® is 2500 Volts,
The secondary voltages on the
transformers, is S&O volte* with m s volts from either leg
to the center tap*.. Table
.. .
,.
.
.
.
.
gives the names .corresponding- to the various
symbols used in the -diagrams of the transformer vaults.
Table Xtf lists all high voltage equipment as to type and-
style* giving the location of each piece of O g n l p m e n t Table
V lists ,hl^h' yoltage -e#lpment according to the bnildlng-in
Which it is now located*.
th&a&a*. ,
.
.-
These tables are at the end of the
Y
o? m s Bio#
'■
.
•
Yhe underground high voltage System on the Mdntaria State
College campus w&e designed for a closed loop feed# as is
Shown in figure I*
However? the underground, lines have been
broken .several times# and When repaired, have not been phased
out# but instead just reconnected^
$he oil circuit breakers -
could not be closed because the line was then out of phase4
Yhis has e w e e d undue-strain' on the' loop lihe# as the majority
.
•
of ,the load has been carried by one circuit*
.
.
•
■
'
Yhe first part of the analysis consisted Of phasing the
f
underground- and abeve^ground limes on the- entire campus* -'Yhe
lines were phased out# by means of army .-field telephones,
starting at Montana- Hall and traveling Bast around the loop*
cosilHg. back to Montana Hall*
Yhe reference point was located
in.' Montana Hall because an oil circuit breaker on the’loop '
system is to be replaced at Montana Hall5 and the phase ordercan be, Corrected -at that time* A diagram showing the changes
:
•
to be- made is located on the board panel in the, transformer
vaui-t •at Montana Hall,
reasons*
This first part Whs- done for two '---'
first* the loop.circuit should be closed.* and to do
this th@ phase sequence as well as the pba.ad order must be the
same all around the loop*
'Secondly* to locate an unbalance in
the campus Ioad5 if is necessary to know which phases the.
various transformers are■ouw
• fh-e' p&stie ourrents SU %W- various builSI'ng^ ■•tmt® d#%eT*&a*4
by -putting Maxl*-aieters on the transformer secondaries and re*cording the:peak currents -averaged over thirty minute' inter*.
vala*
The peak currents are averaged' Over thirty- minute- in­
tervals because the Ilaxi^meters operate, on a thermal principle
and there is- approximately a, thirty .minute -lag Sm the...meter,*.
Worn the individual -building analyse a* two possible .
solutions -will be, prese-ht'Mfe - •--
The 8300 volt line for the Montana State Oollege,-,system,
comes from the- Eostana- Tower OompahlW* -suh-^statlon#-- .BIgure
0 shows a ,single line diagram- e-f the- ,Sub^-st.atlohs
The. 41-60- ,
volt1buses -pass through IWuetlen -Voltage regulators which maintain- the voltage .approximately 'Cen--Stant*,
There are two--'
4160 Volt buses- from which the college may take Itts pbwer*.
In cash- of -a power failure in- one -of the incoming -$@*.#0' vplt
lines;# the, -college can be fed from a second 41,60 volt h u # a-a
1%
0*"
%akon fyom the 4160 volt buses
through a ■switching arrangement, of knife switches^, and 1-s con­
nected to two 360 Sya* Vhree phase- autotransformers, connected
in parallel*
The -aufcotransformers have-Connections as shown -in figure
B*
T M s the Campus line, is a 8300 Volt grounded star* 1388
Z
3OO V /in e
/o
c o //e g e
SINGLE L N E D IA G R A M o f the SUBSTATION
CIRCUIT N the C O LLEG E Z 3 0 0 VOLT L IN E
figure
2
volts from ground to any one ptwse*'
From the sub-station^.the thro© phase lino goes under■ v:
to arise la the m*la gwltoh vault* looat©d jutt/ goutb
Ol the.: hub-stationfe At- this point the three phase 2500 volt
M n e Is takeb' to the o-ampus cm a mixture of #6 wosthor proofed*'
and rubber covered* hard drawn copper wires* counted on the
Oenter orossarm of the 50*00© Volt line to Mvihgstonv ’
BARBAGK&y WOOh &&BO&A#0BY* ABD #3&3&aRf
.
$he power for these buildings Is supplied by -two .separate
systems*.
Dbcated hear Eleventh Street on an elevated' platform
is a ¥5 KVa transformer.*
This transformer .supplies the light­
ing and plug circuit loads- for these- buildings*- Located on a
pole between the Military Building and. the North Barracks are
three Iq Kva transformers,
fhe connection is an open delta
with two transformers' in parallel on one leg*.
At one time the
lighting load was taken from the parallel arrangement.
How­
ever, it now serves only to ''provide three phase .power to the
lUf&l Engineering Shops,
Pigure 5 Shows these transformers
and their present connections,
The power' required by these buildings is very great*
much in excess of the Svo available at the present*
The 22©
volt and H O vplt single phase loads are almost at their
maximum*
■
There will be some additional loads on these lines
after the start of the- new fiscal year.
These loads will
AAAAAAAA
/?c7 7<ec/
C UtjZ-jGnf
32f)
amp
Ac, fJoI
omps AU6 a
IB Q a
T R A N S F O R M E R S fo r WOOL LABORATORY,
BARRACKS, and the M IL IT A R Y B U ILD IN G
ficjure 3
X'2
eoaslet of motors in a new shop to be looated In the South.
Barracks*. •fhe^e-are two- SSO volt single phase electric
'-
welding machines which are now oil.-two legs of" a three phase
c i r c u i t T h e s e will he changed over to the SSO volt single
phase line-S'-,BVen with this new load -on the TB Kva- trans~fOnwry, there will remain an excess of available capacity*.
■-■. The three phase reqpilraments are much worse®.. Six three
phase welding machines an# several small three phase- motors
take
a'O w M n e d
name -plate total of 197 amperes-*;* T h e ^ e M i*"
Ing machines- are for a welding class*, and the instructors
attempt to- use all Of the machines at the same t i m e w h i c h .is-Impossible#
The- three phase circuit is fused for 60 amperes 5
and-' the •fuses blow quite regularly& which indicates that the
transformers are overloaded at -least 40#* •
f® properly supply three phase power -to--these buildings#
an open delta circuit employing two BO Kva transformers will
be ^required*
-t-Ms -lohd#
There are several possibilities for supplying'
One would be to -erect a platform where the io Eva
transformers are now, -and-'mount two -SO Kvs, transformers there*
A second -arrangement would utilise the excess. Kva- in the.75
Kva tran-sformdr*
To do this# a 50 Eva transformer-, S o u M be
connected in open delta, with the YB Kva transformer.,-, -and a
BT& Kva.y. or a -BB Kvs transformer* whichever is available,'
would be ',paralleled 'With the'YB- Kva transformer,*,,
if a 07*1
I
IS
Kw-
1$Ms MKPmagWent w w l d allow for
future lsastallatton^* ,lew secondary feeder % & n m would be
required lu. -all cases^
Available equipment will determine
which alternative.will toe used.
BOB### BOOBB
Figure i shows an .Open delta transformer arrangement
employing a 85 W a -and a YB W S transformer#
Although,the
indicated leads tend Sb show that there is a, waste of. a w l l *
able capacity* it is not so*
The load on the YB Iva trams*
farmer as- indicated^ is mainly the lighting load, ' fluring
the winter months^ #1% large- -heating units# operated, -toy-"
three phase motors^ run the majority of the time z These- v
W t o r a - are-Quit#
amperes per phase*
having % nmaepldth
This electrical load* which when .combined
with the lighting load#,'very nearly approaches the"W d rating
of the W
eonnecfldhw
Eowever^ the $5 W a transformer, could
toe replaced With-two 10 Kva transformers In parallel*
The ptoEh lead at the Eudson House oceurs in the evenings
-after eight o*clock*
The present arrangement In the Agriculture .Building eon-*
slats of two IG W a transformers connected in parallel as
Shown in figure- 5«
These transformers are overloaded, the-
peaks averaging approximately 25^- overload#
Phase A
Phase B
Phase C
To
Sub- Sfefhon
I
7 SKvo
/VWXA^jAA/WN^AA
R a te d
RUHy e n t
3 / 2 6 <7
/ 0 ^ 7 ^
/Ac/c/c?/
C an n e n t
Z8o
■ ZLOOo
18 R a
T R A N S F O R M E R S a t the HUDSON HOUSE
fK j U F e
d
Phase A
Phase C
IO K v a
IO K va
V S A /S A /S /W S /W
/W W W S A A A A
VW W W W VV
W W W W W S
R a te d Cuhn e n t
A d ual CUHHen t
/OP a
TRANSFORMER VAULT a t the
A C R tC U L T U R E BUILDING
fig u r e S
&6
■ Stis' 3;6aia
BuiMlug. -is-
‘d.o$iat'a.nt^■
Since % e W l n 'activity in this building consists of classwonk
and ofiicB'
the w i n electrical load- is due to lighting,#
The.creejner^ located in- the Agriculture Building,
e&B&ains aoae meah&niaai. aghlpbent driven h y
veit mptor#*-
JBewevers this portion of the total load- is intermittent#'
Additional load is incurred in- -the winter-months due toa'large bank -of 800 watt .lights used in the Agronomy green*
house for e5rperiWntai work*
^
'
■- The peak Ioad^.averaged, over several days,- is H S smperes
and occurs- in. the.morning*
To supply this, load-, a SB .Itvas and
a B JBvh tr&nAf&r&ermay b&
Also, & io
former could be paralleled with the present arrangement.*. Either
Changc-will' allow, a capacity capable of suppiying 182 mtperos^
Any future electrical installations in this building
Should be put ton the -Toast' loaded winding as shown in:figure S#
- --
8 T # K eavi&iG#
■This -vault is located on the Southeast corner of- the -Stack
PSy 11 ion#
Contained -in this vault is one 26 Sva transformer#
The secondaries of this transformer go up to the bottom cross-
-t##
Mvingston*-
carrying the
vnl% lino to
This transformer supplies power to all. the barns,
street lights in the area#, the Grain SuboratOry^, and the' -MtenS*
lOn Buildings* 'Also, at this vault, IS the. beginning of. the
17 ,
uridergziounia. .eastern#., fhe 2090 volt'lines come down fi’Om the .■
power pole due last of the Grain Laboratory, ' '• ■
fhe load here has. been steadily- increasing due to -hew'
equipment being, installed in the various buildings,, and, this,
load will have to be taken care of with increased transformer,
capacity,
Ihe indicated, loads In figure 6 show that the, '25
Kva transformer is now' overloaded* .Iven if the loads werebalanced on the two lege, the transformer would- -still be St­
overloaded:*
Since this circuit was metered, -a large 10,000
watt' heating unit has been installed in the Grain Laboratory^
These, two
and an Autoclave WaS installed in one of the barns*
new additions will greatly overload- the 25 Kva transformer*
To care for this'load, a 10 Kva transformer could be
paralleled with the present 25 Kva transformer#
■•
However, ..a
37-| Kva transformer would allow a small margin for future
installations in these buildings*
■
& m i 8 &&&L
-- In the. past year, the electrical installations in Lewis
Hall have ■steadily increased# and it is probable that during ,
the. coming year# there will be- further -additions#
-The Health
Service- -has .obtained new diathermy equipment which draws,- ,.a
-heavy load*- In the present installation, there is a 25 Kva
transformer supplying the buildings lighting and plug cir­
cuits,.
Connected to the'25 Kva transformer in am -open delta
Phase C
Phase B
Phase A,
PS~ K v o
\A A A A /\/V V V V V V \A /v
/9a7<7
Rated. Correnf
Actoaf Curnent
8 fa
TRANSFORriER VAULT a t the
S T O C K P A V IL IO N
fiquKe 6
19
aiyouit la a
Eva, traaafqmer to
a small, three abase ,
load, as -3.nd.j-Gated, in. fIgBr-e 7> .Also tliere is a is Kva Iz1Qns-
former mhieb supplies. a& %-Eay mao&iaa in the Bealth Service* .
%bi@ transformer belongs to the Eealth Service+ .#&* load on
this transformer la trivial* .baring, the warm up period of the.
X-Eay equipment,#l each leg draws S amperes*' .Then during, the .
exposure# the current has a maximum, of BO amperes for .-a short
period* usually lasting but a few seconds* .
Bhe #8 Eva transformer. Is' 15# overloaded at the present* .
Ebe Eva capacity should be iherea&ed,
Eo plan for future
electrical Installations#.the -BS Kva transformer could ,be re- •
placed with.a S7-§ Kva- transformer* .EhAe would. I have;-A-’small
margin for the future Installations* ,
MOBEAEA E&&&
■,■
' ' -'
-
The transformers In the Montana Eafl vault supply power"
to. Montana Hall# the Service Shops# and the eld Mathematics . .
Building* .To supply this load# there la an open delta arrange­
ment using a 10 Kva and a 18 Kva transformer* .The lighting
and plug.
.circuit leads are carried by the 15' Kva transformer* .
The load here As' mainly a lighting load* -However*. In
Montana Hall# there are a large number of electrical.office
machines.*-
In the Service Shop and the eld -Mathematics Building
the load As mainly machinery* and a good -share of that:'is
Phase A
P hase B
/ S Kva
Vwvvvv
yVVyyVVW XAA
Had
AAAAAA
A c fu o / C u yye n f
TRANSFORMER VAULT a t LEW IS HALL
-figuce
Z
titure©'phase m a c h i n e ^
'
■ is indicated in figure 8, the peak loads on the IS-Kta
transformer- average 117 amperes»
fat a 15 K w transformer'
this represents an 81$ overload*
fills load seems highs yet,
'uiv. •
for three buildings^ 117 amperes is not unreasonable*
,■ ■ Sith the completion of the new library Building* and the
proposed new Service Shops* part of this load will be re­
moved*
But. until that time comes*, this overload condition
should be .corrected*
A SB KVa transformer would carry this
load, and at peak load* the transformer would be- 10$ over­
loaded*
FHYSIOS BHlhDmo
At the ,present* the lhysics 'Building employs a 7§ Kva and
a 86 Kva transformer in am open delta*
Ihe indicated loads, "In
"
.
.'C
figure 9 are the peak'loads found by checking the current with
Ma3Ei'*meters at various times* .
The only three phase load In the:building is a motor; gen­
erator set which draws 1# amperes*
The 7^ Kva transformer is
operating at: almost 100$ rated load*, but the 85 Kva transformer
is operating at, only 18$ rated Current*
Therefore * the arrange­
ment. .hero could be a 10 Kva and. a 7^ KVa transformer in. open
delta, with the 10 Kva transformer supplying the lighting load*
This would leave some available capacity for future installation*
To
Phase
/4
Phase
B
Phase
C
Hamilton
Holt
A/VVV^^/VVVVXy^
TB
f^ y f i cs
BuiIctrVj
A c fu a /
R o fe d
Cu HHeni
C u rn e n f
//Q a
TRANSTORH/CR VAULT a f M O N T A N A H A L L
figure
3
Phase A
Phase B
Phase C
T0
Wonton o
Ho//
Te K vo
n
Z5~ K va
V X A A A A /v V V V V V \A /\A /V V V V V V
AAAAA|AAAA/\^/\AAA/^j^
/R a f a d
Ca /'T e n t
3 Z
/(9<9.7 c
A c fu o /
Cu w e n t
3Z o
dO a
/3-
TRANSFORMER VAULT at the
P H Y S IC S BUILDING
figure
9
' BAMI&TO# S m &
/
Semiltitizi Hall haa onb o f .the worst load unbalances in
the entire system-*
Metered With a gmap-on ammeter at random
timesS ah- unbalance as bad 6# 90 amperes in one winding and .5
ampere# in- the second winding of the transformer secondary,
hare been detected,
Am can be seen in figure 10> .the power'
for this building is supplied by a SS Kvs., single phase transformer*
., 100% current on a Sb lra transformer is 108*’7 amperes*
therefore#- one winding, .on the secondary i s -5% overloaded,- while the other winding is carrying only 50% of i t r a t e d
current*
Io correct this unbalance> a good portion.of the load
on- the overloaded winding should be shifted to the underloaded
winding*-- -Shie 25 Eva transformer could be left in this
building, even though it will only be carrying rZ5% rated •
current r
$wo 10 Kva transformers* ,paralleled* could-.supply
the'necessary current* but the vault-is too .small to safely
accomodate them*
However* as the wiring in. Hamilton Sail la
outmoded and unsafe, plans have been started to have'this-'
building, rewired.
If and when it- is rewired*, the- load, in
all probability, will be larger and the 25% margin on thetransformer would care for the- increased load*
to
IW a
3Z a
A c f u a / C u ^ e /? f
TRANSFORMER VAUETat HAM/ETON HALL
f /g u R e
IO
At the 'present Serrick Hall has three independent ,pcmer
Vi
eirouite,' ha eh operating 'from a 50 Kira transformer^ as ih
figure H .
Baoh eirehit ih on & Bifferent phase.
In figure
the center transformer' supplies power for all the electric
stoves in the building*
It is loaded to SSfs rated current*
The other two transformers supply the plug and light circuits
fox* the entire 'building*
These latter two transformers are
Carrying only a fraction of their rated current#
Still, the two circuits cannot be fed from one trans­
former, even though one transformer Could carry the' combined
loads, as an additional load will be added to one of the plug
and light circuits during, the summer months*.
This additional
load will be caused by the new fourth floor of Herrick Hall
which is being constructed at the present,
There- is a wdW'tS'.'of,available capacity In this'building*
41so there are two possible changes that could be made#
First,
the two •50 Kva Urangfoxmerb supplying the plug and- light cir­
cuits could be replaced by ohe YB KVa transformer-*
Secondly,
the-least'loaded of the 50 Kva transformers could be -replaced
by a 25 ICva transformer, maintaining the three separate cir­
cuits,
The power needs -elsewhere on the Campus will deter­
mine which plan is the more advisable.
Phase B
Phase A
Z2T
Phase C
Quac/vany/e
P/at&c/ ( P u H r e n f
A c fa o l C u r r e n f
//O 67
/%C%7
TPANSPORBCR VAULT at HERR/CK H ALL
//
88
'$he: arrangement at the Qaadrangle consists &.£■ three
traasfoymepe .^applying single 'phase power t# all bail dings
In the grpup*
fhere 'art two 25 Kta transformers,and one 37&
:
Kt.& 'trantfoMer*',' Bae secondaries 'all feed into a large-"
SistriWtion panel t
,
'
'
:
■_ .
■1 W e r a. period of eight days 9 the peak loads #e&orded
are-eh### in figure 10*, Qbue there'&$ & large-waste qf %
available capacity.
Sinse, the; power feeders to all Quads corns from, the'S-We
power, panel* It would be no trouble to shift the load -of one
of the Sb- Kva transformers to the.other*-
By doing'fhiB> ■a
2B:.Eya transfOWer- .could be- removed for use, elssifhsre*,
IhSa
arrangement will operate both the remaining SB IVa and 'the'S7§. -Kva transformers- nearer the Ir rated 'oapa-eities*
Wnder
this arrangement, any future loads should be placed on the
5 7 Kya transformer*
'
'
., -•• ■
‘fd'V.-sWpiy power-'for the quonsets# a single phase* SS Kva
'- .y.
viv'
'
,
,
"pole mounted transformer is used#.:'-Kher,;,l^ab htre Ponbista of both fluorescent 'and Incandes**
,
V:; r ' :
bent. 'Iightpi and split#phaSo"' fan motors*
Bue- to the- drop in
onrpllmont*/only four out of the, #1# ymlta, are -in use. at the
present*
If in figure- 15* the loadb- were balanoeh., on the ■tyo
O
O
O
75
Phase / \
Phase S
Phase
Herrick
HoH
C
aa
Z£~Pva rn 37-k Pwa rh ZP Pva
VW VW W W V
A A A A /W V W V N
VVW W VW VV
AAAAAAAAA/V
V V XA A A A A A A A /
AAAAAAAAAA
Aj
To
ND
GiH/ 's
Quonsef s
P a f e P CaFkenf
A c t u a / CuF k e n t
/6?c
SZa
C P a / 1& a
/(98
//Z a
39 a
TR AN SFO R M ER VAULT at the
Q U ADR ANG LE
figure
/2
7a
Iegs5 the 35 ICya transformer could h-e replaced by a 15 Kva
transformer;
This present load would then operate A 15 Kva
106# rated current*
#hl* overload is of abort
duration in- the evenings' between nine and ten o 1Clock6
'however, this could be done only if four units or Ieee
are used*
With the- eapeeted decrease In enrollments i t -&&,
probable that no more than four of-the units will be used*
;
,gsie 8#d e n t IZniotL Building has had muph' ad^ftlonal
electrical apparatus temporarily.installed to oare"'#r the
■large number of students boarding thdpM-' ■
.
' •'••■". '.•
Aa originally planned* the 60 Kva transformer will/take
. . =‘'
•
bare of all the load except the new equipment, #ro# figure
14'&t is-'seen that'the transformer is wall balanoe%.,hut■Is
operating at a 85# overload*
right at the transformer*:
# w lines have been eonue&ted
--l'
io care for this overload* these .
extra', lines could be connected to a 16 Kva transformer*
##
this boarding club is a temporary measure* this overload will
probably drop- off in the future*- but it should be -cared for ,
’
-at'the -present*.
&0BBR#f8 Ea&&'
-’
. -: ^ -
lot 'so *many years'ago, the trahsfomer at Robert-6S'.Hall
was 'greatly overloaded*
At that time* the 05 Kva transformer
waa replaced with a 50 Kva transformer*
At the present, one
I
-L
n—n
-----_1— [LU---------L
Phase B
Phase C
Tb
Q u a dranyle
2 S K vo
VvVVVVVVVVVXA A A /
Z\A/VVVVY/VVVVVV\
R a t e d CunyjG nt
A c tu a l C un n e n t
/06?. 7c/
GOa
777
TRANSFORMER a t G/RFS OUONSFTS
figure /3
Phase C
Phase A
VVVVVVVVVVVVv
A A A A A ^ A A A A A /N
R a te d C u rre n t
A c tu a / C u rre n t
2 .7 7 a
^ 9 ( 7
TRANSFORMER FAULT a t the
S T U D E N T U N IO N B U ILD IN G
figure
/ y
eeeoadazy wlad&ag of
#0 0%% teanefoemer is overloaAeii*
A b indicated: in figure- %.$■$ ons Windiag- carries S80 amperss*
and is B©^ overldaded^- while the- other w-indihg ,carries ohlgr
!'SB awBores* which id 'Wt #3# of the rated eurreata' .-< ' '". .Eeaee8 the correot-ion that is necessary' here ■is to change
a large portion of the load from the overloaded leg to the
less !ceded leg of the te&hsfcrmert.
%h@ three phase' Idad'
consists of two fan- motors in the attic*
ttsCd very often,#
Aiese fans are not
If they were doth on at the -same time.#’ they
w'oald -overload the 8 Sr-B- transformers»
however# those.'tfan#^
formers- have never exceeded the rated tSmperatnrc rise# and
tor the small periods that the- fans would he used# 'the over*
'
■
load weald Cause he.-trodbla* tf available iKbwauwg&x* '&*& ##va.- :
;
tm m to m m m
Replace -## - t m :B W a t5^ansfo$mie>B b o w ,used<.
'
'-
-
BfAB &AB&&A#&a%@8
•-• this, vault- contains seven transformers#
'" ' "
Starting' on -the
left -of figure IS, the first transformer- supplies single phase
-power to the new -Womlcai- Engine-e-ring- laho-ratory housed Ih the
frame, building Sorth of the fiyan.laboratories#
fhe second
transformer 'suppiios the lighting -and 110 volt plug circuits
for the entire building# , fhe n m is three tr&ns-fo,rmer;s -are
connected in a- closed, delta# with the secondary windings in
parallel# to furnish $ -three phase H S volt circuit for the
Electrical Engineering- ..test floor#
!he- last two transformers
Phase /4
Phose B
Th
SfuJe-Zit
Union
S O Pva
W W V W W W
/V V V V X A A A A A
/5 8 a
AAAAA^AAAA^AAAAA^
j
V W V N
f& a
TRANSFORMER
VAULT a t ROH A LL
figure /T
Phase
~7z K v a
I
vVVXAAAAA/
/v w
T0
K e a tmy
Ab/,/
/4
/0 K v o
vXAAA/VVVV
A A A A ^A A A A
A A A A ^ jA A A A j
^ W \A ^ |A A A / ^ ^ ^ W \ A | |A A A ^ |
R a f a J Cuvrent
2/7(7
/
TRANSFORMER
RYAN
figure /6
AAAA^
^A A A A
6m o#e& aelta oll-cult to
830 VOlt^,- tbyee #h&38.
power to the entire ^Mllaing:*'
■
■
,
The laed In this Wilding la m&laly aaoMnezy* and the
peek load will od#w# 1# the aftewoohe during the laboratory
brasses, ■ This peak’will vary from day to day> -and from month
moat&f depending upon the type of experiments being per*
fbfmM;' In the laboratories,%
The
.
%va transformer for the Ghemloal'Engineering &ab*
oratory is unbalanced^ and should have the lead ehahged.tb
even-up the ahbre&ta in both legs*. The 10
transformer
-
supplying the light# and plug glrbuita for the Byah laboratory
lea la greatly Overloaded in bath lege*
Even if the IQ Eta
aad ?& Eva transformers were paralleled^'they would remain
overio&de'#
To earroot this# the 14
evb
trantformer-bould'he
replaced with a 15 Eva transformer, or a g Eva transformer
oould be paralleled with the present Io Eva-treheformer*
transformer bould be paralleled with the arrangement^
The
' '- '
so. that all.lighting and plug Oiwuits in both buildings
would operate from the parallel bc#binatlon» 'The three phase
H g Volt bIW u l t tan draw a load of
ampere# in eaoh leg
without overloading^' so ■this oirquit is alright a# it stands,
The darre&t# Indicated on figure 16 show a oonslderable uh#
oh the 2 # tol-t tlWe,,#&###' line*
This unbalano# -
oould be caused by the unbalanced- three phase voltages#
,•file Iiypee phase circuits could remain: as they are*
Eewever* a
possibility whic.h would add capacity for.the futures as well as
Clean up tbi'd ,wulfc would be,to oloee the delta? o n .the'SSO
-.Wit circuit, with another .50 S W transformer,
fhen the 11-5
volt three phase,voltages could be. obtained from,.the..center
■taps of the SO Kva transformers,#
fhis would, eliminate :the use
of the present three 5 Eva transformers which .are in closed
delta as shown in figure 16*•
;
'
-.
The .present arrangement in the Heating plant consists of
two separate systems* one for the Heating Plant* and one for
the laundry*
The as individual systems both consist Of two
10 Eva ,transformers, in an open delta connection, with a , .
neutral line on one of the transformers to supply 115 volts
lighting
, The -load on- both of these systems remains .,practically
the same from day to. day* the major portion Of the- load being
electrical machinery*
•/ The fated current of a 10 lsa transformer Ss 4#&5'amperes*.
.From,figure
it Is seen that #* eaebndary winding -Cf .any
transformer is carrying over 7-0 rated currents
Thus with the
loads runhihg''reasonably constant* there Is a large waste of
available capacity in this buildings,
Since a 1.5 Kva trans­
former is rated at 65*8 amperes for -each secondary winding.
Phase B
P hase A
/O Kya h IO Kva
18 a
IO K v o
A c fu a /
C u rtjG n f
Tb LounJtjIj
h /0 K vo
K lZ a
ToHeaffnj Plant
TRANSFORMER VAULT af the HEATING P L A N T
TicjUre /7
39
an open delta connection of two IB Eva transformers could,
sugely t&e olaetriaal needs of both t&e Beating Plant and the
Iaundry9 even if the peak loads Were #
occur simultaneously^
• To do thisp both transformers would supply the three
phase loads to both bulldlhge* 'Then9 using the'neutrals .On
bofh transformersjj one transformer could supply H S volt lines
for the laundry* and the second transformer could supply 115volt lines for the Seating' Plant*
'
-
'.
The- previous arrangement in the Gymnasium Building
consisted of two Y& Stra transformers In an open delta for the three phase load*
ing load*
a 8$
Waasfdfmer for the tight*
During the month of -Aprilf 1 9 # * a new lighting
system was installed in the large gymnasium*
This new light­
ing system would M v e added IS9OOO watts additional load to.
the. 25 S m transf.o$%orf; which would have -greatly Overloaded
it* 'Hence9 a new 25- Kva transformer was installed to supply
this-' new lighting system* as; is shown in figure 18*
-The total
load on this new transformer is 115 amperes in each leg* the
load being equally divided*
system is 86*000 watts*
The total wattage of this new
At maximum load* the new 35 Eva
transformer is 5^ overloaded^
-
The- old 85 Kva transformer -is
now only about Qaf9 loaded at peak loadii
Therefore * if the
two transformers- were paralleled* they would share thp lead
TRANSFORMER VAULTaffhe GYMNASIUM
figure /8
at all timesj, sm&
would Ta$. overloaded*,.>
t
Th%& ^iii allow-future ei-#-t,rleal -lmatallations•in -this builds
ln$ without overloading the transformers.
1Sae three phase load consists entirely of induction
The tvo-Tfib
&re net'now overloaded*
t
(
.and may remain, as they are* ■ •. Peak loads in this M l M t n g occur in the evenings.;
when the gymnasium' light's are all on* '
■
m e i s m i # w * Bmmaia
ana e m m w m r
'
■
.
the setup for this group of -buildings is- similar Sn the ■
■
Girl* s Quonsets#. The load now is much less than-, it was Wheh -
■
the B$ 3£ya transformer was installed'*"- Ehe. Sen-'*a. Quonsef'Siwhich were-, erected to house male students.,*, are now Serving as
storage space*-
Ehe present load 1-e mainly lightings- Biis-
trensfoamer' .suppllee ^ower t o 'Brldger B&ll* the
innox*. the Susie Building# and' the Sfenls Quonaots-*
'
-- -
-Ehe 2300 volt lines •for this transformer are topped'’Onto
- i',
the line 'between the -Ghemistry and GyanasiUm Buildings*
-Y - '
'
She present'p Ouk lead on this -transformer is 7$• amperes • •
as' Indicated- in figure 18$
any gre-dter*
,30 amperes-*-
Shls load will p.roMbly never he
She load at might is much less* averaging about
SC take care of the peek load will require 20 Eva*.
Sherefore* the 26 Ey& transformer-could be -replaced with, two
10 Sva transformers In parallel*
t f r
O
Rhosa A
T
J.
Rhase S
J u n d io t n <6<s /w <?<?a7 //?e
e r ty /s fr y a n d G y m n a s /u m
BuiJcJiny£■.
Z S K vc
VVVVVVVVVVVVVVV
/V\AAAA/YAAAAAA/\
R a ia J CuHBent
, f
Actual C u B B e n t
CSa
T R A N S F O R M E R fay M U S IC B U IL D IN G ,
M E N 'S O U O N S E ES, B R ID G E R H A L L
and IR
C H E M IS T R Y A N N E X
figure / 7
4$
cm&smY
At. the
.
'
", "
%b# &oa& &t the Ghemiatey B&ildla'g is
supplied b y &a @pe% delta teaaafaemee &9%aa#tioa ee ebeea'-l#
f igo.e© $#*
She lighting %ead is -eh' the 'W Kva teamsfe!#i#e$.
Sb* load la this bail&tag is galte complex*
It apaslste
.af' li&ore&oeat &&<% iaoendOeoeat l l G h # & g % #&& m o t e # * eieotronio'
-e#lpmmt^. small rmiaiag
end he&tlbg eiameata*
She -
pp&te ■comes claeiBg. thh afternoon .laboratory classes*
Dae to the reae#t ventilation project &a this building#,"
-
.
>'
•
,
W e r e roitains eonsldereibiO- three phase load to be .connected
W
tW
tran s f o r m e d *
I h e additional load
aeees^
sary t@ %epl%#@ the !#'%#& traaBformsr with a 8&.'Bva iraa#*.
former* . iDhs #& K v a
&& papabls o f taking ''Wis-'
l % o d # $ 3 & lipad Ghly if tha W o o M a z y W h d e .are balanced*
%hl& .would e&ta&i r<moVi&& ab#it. $0 amperes ImaA fra* the-.
heavily leaded leg* a#.putting" it on. the Otheir lee# leaded
Icgi
,
P ha se
/4
JT9 /<vy
/ywvSj
P a f e d
^ww\^
/ww\|
^w
w
n
Cuvren /
TRANSFORMER VAULT at the
C H E M IS TR Y BUILDING
figure Po
4&G W B B 4 & mA&YBIS
imdiVia#al Wlldlag aaal^aeB* it Is
seeji that there are considerable changes, to be made # . So far*
only the loading of the various transformers has been ©on*1
sideredo
Of greater importance as a factor causing unbalance
»'
in'-the system#, is the loading on the phases of the BSOO volt
line*.
Under the present setups the K W capacity on each phase#
Wglsotlmg Open delta circuits which present balanced loads:•
t&'.the e@9& w i t i&aw; figured from 100# rated, egpab&ty of
i
the transformers* is -as follows*
Phase AB has a Eva of BI5,
Phase Be has 165 Bra# and .phase UA has 163 K W *
Bht this K W
'shWld'W agually dlWdad e&m&ag the-tW&e p W s W *
BoWWi&j,
the -abtuai load figured -on. the basis of the peafe -WlneS:* li
all peaks occurred simultaneously would show a different un*
•
:
balance*
Figuring the different phase loads on the basis of
^eak loads* again Ignoring open -delta -circuits#, phase .AB
•carries BBl S w :
# .phase B0 carries BBb Eva* and phase -BA has
but IBQ Kva*' Sere again a great unbalance Is noticed* .
■..■-W ■-Correct this system* first the transformers must be
■arranged to Carry the ■load without overloading*, and secondly*
the ’transformers must be connected to the. phases In such a
manner that the phases are closely balanced*
better voltage regulation all over the campus*
Ihis will give
Ihls portion
-
4$
of the analysis will he taken up in the pages to follow,
. ik matter Which has nothing to do- with the unbalanced
voltages oh the' e#mpu@g but is of importance as far
safety
Of the system is concerned* is that of the automatic oil
circuit, breakers found in the vaults*
.
These breakers- are
placed here ,and there without regards to their current ratings*
If the heavier breakers ware placed i& lewis,#&ll and Montana
Sail.* and so on* tapering the ratings as the buildings get
further,from the a&ur&e+ &a& u&i&g the Smalleb breakers-on
thW'"''fpur' lises* there would be- less power failures on the
campus*, At the present* a good heavy overload -in the Byan
laboratories- or any other building on the loop*' will practically
'I
always- open one of the type E breakers in Montana Hall*
If
the oil breakers were adjusted near the current actually pass­
ing through them* then -a fault current would open the breakers
in the building where- the trouble is* without interrupting
the service to the rest of the buildings on the campus*
For a solution W
will- be given#
this problem,*: two- different alternatives
The first alternative will have- In view the
far future needs as well as the .present needs*
The second'
plan will give -a solution for the immediate relief of this
problem*
■ •
FIB0T A&EB&B&TIV#
fh© present load is approaching the capacity of both the
underground cables end ttiae autotmmsformdrs.
.fh& overhead
lines from the eu'b«statiou are overloaded already*
fhe elec­
trical loads that will-follow with the completion of the 'library
and
two proposed bulldluga w h W * may seen be constructed^
together with the ever increasing mall electrical loads added
here and there* these lines will he overloaded*
Many of the
Cables are the original ones installed years ago* and their
insulation Is deteriorating* and at the same time the pro*
tec tIVe armor is rusting away*
It is a known fact- that much
of this cable ,will have to be replaced* and an appropriation
-already has been requested to Install new tables*
Therefore*
when a new line is installed* ,it would be advisable to use
a four wire cable that could e&rry a 4l@0 volt grounded star
o&roult*
4iaee a 4160 volt grounded star has a voltage of
4l,6Q/l;*75g or 240® volts from any one line to:ground#; the present transformers will be able to' be used*
Then the
college lines could come directly from the 4160 Volt bus at
the- tubvetation* . Also by omitting;, the autetwaasfdweps at the
aubvetatioa* the voltage regulation of the campus line would
be improved*
'
.
; • -A chblo smaller than the one -in-use today would then
'carry much more load than would be noeded* 'Many sections of
the present cable are n e w .and in good condition*
These could
be tested with a Segger to check the insulation resistance*'
awepta&lg* a
wire oeuld be b&rl6& alo&g with the
g o # aaotlo&e of the #rese&t three wire oable to form the
four Wire cireulti
'To take care of the loads ih the Various buildings# the
following chshgee ehonld be m a d #
Ihe three 10 Eva. tyaneforgerc at the Barracks may be
removed^ and the 75 Eva transformer moved up to the alley
between the Barracka and the Military Bulldlhg*
A 06 Eva
traobformer would then be paralleled with the 75 Eva tra&e*
former* and a 50 EVh tramsfcmer should be cohUGcted i& &&
wpem delta with the parallel arrangements
The Hudson House may remain as it is,
-
The two 10 EVa transformers &a the Agriculture Building,
could be replaced with a 86 Eva and & io Eva transformer in
a ,parallel connection-#
At the Stock Bavlllon* a io Eva transformer should be
.
.
.
paralleled with the SB Eva transformer already there*Ih -hewis Ball* the 86 %t'& transformer could be paralleled
■with ah additional 10 Sva transformer* together with a Ii Kva
transformer in ah span delta circuit*
Montana Hall could have a 85 Eva transformer to replace
the heavily overloaded 15 Eva trahefo^mer*
The 10 Kva trana^
former should remain there in an open delta with the.85 Eva
transformer#
Gha #hyai<&8
t h e - t r a # e f & y # & r cot&a
b0'..#eBio?#a. a#a a %0 IBbfai g w -&
#
&*&' &r@AxKPo$m#y w*^ao.W&
opeh dalt^. Gha 3L0»%y&' "GranafQmer- sapplyhag t w
Ixigvmid p%u^
wiitt
AW&tm W l
1» alraw^- ther#^
-
'
*#y w t a l A tha &S Kra
-
-
3a- Be^ylak Ball tha M
figiiW H
-
-
that
- .
.....
Kva
Gha Iaft'of
,should ha retaovM and be replaced b$- .a -SB- - E w
$WWfdarner# <
•
■
' ••
1 -/'<•■•"• ■
■■■•', -AG Gbe <^&&xwglo|, one1 of # W Bs Kva -GrampfoW o r# can •
be removed^ If
load Is reconnected G o t h e -other SB Kva
'trdmeformer •in tte&G W a l '
• '-
-' - !Bbe BS &v» tranaferweyg %% the Gln'fe -%ohdeG@ gad the
ladle Balldlng should each be removed and replabe'd with two,
IO-Eva .Gramsfermera In -parallel on each pole*
- In the SGudsnt WniW* ■the -new line# cdsmeoted tp. the •
WbBhdary of the SG K W tranafo%ief ednid be dlaconnected
end recohnocGed to .n IS K w tnanbformer which cpnid be Ine
stalled in that vaults.
Iobert->■% Edll may retain W e ti-anafoMerb that ape
there mows
•
•
'' -
„
.. ITi the Byein 3,ghowte#.ee^ all GWhafdiwerb may remain
W e same with the 'exception of W e 10 K w Wanafoamey- Stipply^
ing the lighting load*
$hia thanaformen should be removed
aa& aeplaea# with, a
Ksra transformer*
treaafeemer per&lle&M %o the
4 50 KVa transformer should be -Installed
to close the delta on the S30 volt three phase circuit*
Upon
closing the Seltai the 115•volt three phase circuit could
be -taken fheto the eehter taps of the so Hva transformers*
At the Heating plant* -all 'four of ■the- 10 Kva trans­
formers maj be removeds: and two 16 KVa. transformers may be
installed in an open delta to replace them#
''•■
$h& transformers in the i%vm&alum may remain there# and.
the two 35 Kva transfomaers could be paralleled to -divide
the lighting -and plug circuit load*
fhe Chemistry.Building will automatically be taken care
-of.through the ventilation project* for arrangements-.are ■ .
being made to balance the SO,Kyu load* and to replace the IS
Kva transformer With a -BS Kva trah-sfermsr#
However* the. is
KVa transfomer will' -be -traded'-to the- ldntana. Power1Oompahy
Us -partial payment on d BS Kva t-ransfew©r> SOi it will not
be used elsewhere on the campus-*
With the above -changes* all leads could be. taken careof without overloading the trahbformdrs# ■ Ko -db this,- -will •
rbdulrn three- IS Kya traha-f0rmere and' one' 5# -Kva transformer ■
in excess- of those used by the college at the- present*
Uhls -arrangement also gives an excess of two 10- Eva and three
6 Kva transformers*
these 15 Kva transformers can be
51'
obtalmea
monetary output^' l& storage on the Oampna
are W o WeBfcinghouse type 08P 15 Kva line transformers w M e h
cannot be used on the present system-,.
However^ using a 4166
volt grounded star circuit would enable these transformers
to be used*;
To obtain'the third•is Eye transformer^ one.of
the ejttra io Kva transformers Oould be paralleled with a 5
Kva transformer to obtain, the necessary leva*
This:would. .
-
leave one 10 K w and two ■5 Kva transformers on hand- for
future installations^
be .purchased*
The 50 ICW transformer would have 'to
'
.... ■
■■ •
Other new equipment which would have- to be purchased
includes automatic @11 circuit breakers and some -fuse outou%s-f • lene; of the present oil circuit Weakens have ratings
which would permit their use on a 416© volt-circuit* all of
them -having a voltage rating of 8500 volts* ■
With the- balancing of the -individual building leadsas mentioned in the individual building analyses* and the
rearrangement of transformers as previously discussed* -there
'remains only to connect these transformers to the three phase
lines in a way as to
balance the
phase loads*- '
Unlike the three wire circuit where -an open delta loads
all three- phases equallys an open delta on a four wire star
circuit- loads only those phases to wbdUifc it is connected*
Thus# Table % includes all Open delta circuits- as well as
52
TABLE I - PHASE LOADING FOR THE FIRST ALTERNATIVE*
Building
A
Agriculture Building
Chemistry Building
Girl's Quonsets
Phase
B
25
10
50
25
25
Hamilton Hall
Heating Plant
25
15
Herrick Hall
Hudson House
Lewis Hall
25
75
Montana Hall
Music Building
25
North Barracks
Physics Building
50
25
10
10
10
10
50
n
57&
5
50
Total
7&
15
25
3
50
Stock Pavilion
Student Union
25
10
10
Gymnasium
Quadrangle
Robert's Hall
Ryan Laboratories
C
50
25
ii
15
75
25
10
50
50
15
7i
25
10
50
15
575&
373
381#
"iTiilB table refers to phase loading on a 4160 volt three
phase grounded star system, the transformers being connected
from the different phases to the ground cable.
.single, phase load#*
- $he phase eonneet5ioa fox1 the Tarious Mildings: are given
in Table I?
The numbers In' the' eolumne ebrreepoBd to the Era
rating pf the transformer to be connected, on the phase^ the
■ .■
■
'
.
'
transformers being connected from that phase to the ground
cable*
From Sable Ij the total loads' on each phase- ar#
closely b&l&nced*
Bhase O appe&ra to'b&ve me&e' K.--'iaad
tTmn'thb
' . •
other two, but there Is a 15 Kva transformer on this phase,- ■
Which feeds the X-^Ray equipment in hewis Hall, ..and this
*
traaefeiwr la very seldom
c .'V ' - "
asyfload*
•
.
' ''A'--.X.
.--V
A second alternativej which is designed for the 'immediate
future, will now be considered*
-
'
•
With the exception of the. transfomiers in the Ryan Lab-
hh%torieS;j. the same number of transformers would be used*
Ryan laboratories would retain the three 5 Kva transformers
for the 116 volt three phase circuitj and two 50 Kva -trans*
I
.
fPxmers-'for the SSO volt three phase cirMlt*
■
However# the
two line transf.o.rmers cannot be used on the -present systems
Montana fewer Sefepany agreed to exchange- some 5- Eva trans­
formers for the line transformer@*. With the 5 'Kva trans*
formers,..pax>dll:e-lod;.With the 10 Kva transformers.that 'Wore not
utilised# two of the- 15 Kva transformers required would be
taken... tare of#.
The third 15 Eva transformer would probably
M w
to be pi&r&basW*'
between the fl#e% aad-AeGoa* alter*
Batiire *iii be la the pkaae leeaimg# , The wrlaiie phaee 6o&*
ne ctions eti t M o plan are shown la -fable 11*
'
In tabulating this table* the single phase loade mere
-
■
-
*
.
■
•
-
balanced ;on the three phases* ' Although all transformers
appear a n this table* the open delta-and olo&ed delta sir*
Oults add equal loads to all three phases,
■ : The choice of a phase for the different transformers
th keep the labor at a mlnlimm* using present ,ton*
zisotlons wherever it i® possible^
-
55
TABLE II « PHASE LOADING POh THE SECOND ALTERNATIVE*
Building
AB
Phase
BC
Agriculture Building
Chemistry Building
Girl’s Quonsets
Gymnasium
Hamilton Hall
Heating Plant
Herrick Hall
Hudson House
Lewis Hall
Montana Hall
Music Building
North Barracks
Physics Building
Quadrangle
Robert’s Hall
Kyan Laboratories
Stock Pavilion
7|
50
10
10
7i
25
25
Ii
50
25
25
10
15
25
10
10
75
25
25
75
10
50
10
25
50
50
5
25
10
25
25
15
15
50
CA
3
50
5
15
7i
7i
37*
3
5
25
10
Student Union
Total (Without deltas)
230
Total (With open deltas) 389
50
15
235
368
237
378
This table refers to phase loading on a 2300 volt three
phase grounded star system, the transformers being connected
between the different phases.
TableHI- GHaphica/ Symbols Goh D/aynaass
Stjmbo/
/Mame
A u to m a tic
o /l
toce aker^ s/ng/e throw
S
WwwJ
nn
SirXjte throw o/i sw/ich
S w j i e jo h a s e
tra n s fo rm e r
Fuse cutout
i
-L
\
AAAAA
A
L ightn mg arrester
Knife switch
PofenfioI p a n sfonmeH
a
C u h h s nt tnansfonmsy
I
azv^
aa
/\uto Pan sfo nm ey
TABLE IV-a - TRANSFORMERS
Quantity
Tyne
Style
Serial
Manufacturer
Location
I* Kva
I
S
30522
634529
Westlnghouee
Lewis Hall
3 Kva
I
I
S
S
222653
617215
222653
647816
Westlnghouse
Westlnghouee
Robert’s Hall
Robert’s Hall
5 Kva
I
I
I
S
S
S
222564 a
222564 a
222564 a
554366
636193
635750
Westlnghouse
Westlnghouse
Westlnghouse
Ryan Laboratories
Ryan Laboratories
Ryan Laboratories
7i Kva
I
I
I
I
S
S
HSA
HSA
222565
222565
639062
636334
6808007
6882372
Westlnghouee
Westlnghouse
General Electric
General Electric
Gymnasium
Gymnasium
Physics Building
Ryan Laboratories
IO Kva
I
I
I
I
I
I
I
I
S
S
H
H
S
S
S
S
326424
326424
386424
go4o44
326424
326424
645621
645402
2045646
2045291
695855
2005628
698324
645685
Westlnghouse
Westlnghouse
General Electric
General Electric
Westlnghouse
Westlnghouse
Westlnghouse
Westlnghouse
Heating Plant
Heating Plant
Heating Plant
Heating Plant
Agriculture Building
Agriculture Building
Montana Hall
Ryan Laboratories
TABLE IV-a - TRANSFORMERS
Quantity
I
Type
Style
Serial
(Cont.)
Manufacturer
Location
IO Kva (oont.)
I
I
I
H
H
3
11912lbA
3263978
General Electric
General Electric
Weetlnghonee
North Barracke
North Barracks
North Barracks
15 Kva
I
I
I
3
S
H
222567B
1263826B
64li467
3928504
5772859
Weetlnghouse
Wefitlnehouee
General Electric
Chemistry Building
Montana Hall
Lewie Hall
25 Kva
I
I
I
I
I
I
I
I
I
I
I
S
S
S
S
S
102200
129757
329757
329757
329757
329757
222569
80k0%6
50k0%6
3
S
S
HS
HS
HS
654126
651663
635557,
2001076
2001974
6700716
879350
Westlnehouee
Weetlnghouse
Weetlnghouee
Weetlnghouee
Seetlnghouse
Westlnghouee
Westlnghouee
Seetlnghouse
General Electric
General Electric
General Electric
Stock Pavilion
Hamilton Hall
Gymnasium
Girl's Quoneets
Music Building
Lewis Hall
Quadrangle
Quadrangle
Gymnasium
Physics Building
Hudson House
m
1
3
583364
2001948
Westlnghouee
Quadrangle
50 Kva
1
I »
I
10288220
I
3159557
Weetlnghouse
Robert's Hall
TABLE IV-A - TRANSFORMERS
Quantity
Type
Style
Serial
(Cont.)
Manufacturer
Location
50 Kva (Cont.)
I
I
I
I
I
I
I
S
S
S
S
S
S
3
953508
331087
332747
382747
332747
85BIO
2PP 572
2433800
654102
1245113
1240775
1240737
534^24
603083
Westlnghouee
Westinghouse
Westlnghouse
Westlnghouee
Westlnghouse
Westlnghouse
Westlnghouse
Student Union
Chemistry Building
Herrick Hell
Herrick Hall
Herrick Hall
Ryen Laboratories
Ryan Laboratories
75 Kva
I
I
OISC
S
953612
992926
2426917
Kulhman Electric
Westlnghouse
North Barracks
Hudson House
TABLE IV-b - AUTOMATIC OIL CIRCUIT BREAKERS
Quantity
I
2
2
2
2
•
i*
I
I
2
2
2
I
I
I
I
I
I
Type
FlO
FlO
FlO
FlO
FlO
FlO
FlO
FlO
H
H
H
H
H
H
H
H
FK 20
Rating
Voltage
Current
2500
2500
2500
2500
2500
2500
2500
2500
2500
2500
2500
2500
2500
2500
2500
2500
2500
200
200
200
200
200
200
200
200
100
100
100
100
amp
amn
amn
amp
am D
amp
amp
amp
amp
amp
amn
amp
75 amp
50
50
50
200
amn
amp
amp
amp
Manufacturer
Westlnghouse
Westlnghouse
Westlnghouae
Weetlnghouse
Westlnghouse
Westlnghouae
Westinghouse
Westlnghouse
Westlnghouae
Westlnghouse
Westinghouse
Westlnghouse
Westinghouse
Westlnghouse
Westlnghouae
Westlnghouse
General Electric
Location
Stock Pavilion
Hamilton Hall
Gymnasium
Student Union
Chemistry Building
Montana Hall
Herrick Hall
Ryan Laboratories
Heating Plant
R o b e r t ’s Hall
Lewis Hall
Ryan Laboratories
Lewis Hall
Hamilton Hall
Montana Hall
Ryan Laboratories
Opposite S u b - station
TABLE I V - o - OIL SWITCHES
Quantity
I
I
I
I
I
Tyne
I
I
I
I
I
Rating
Voltage
Current
4«)00
^soo
4500
4500
41500
50 amp
RO amp
50 amp
50 amp
50 amp
Manufacturer
Westlnghouse
Westinghouse
Westlnghouse
Westlnghouse
Westlnghouse
Location
Stock Pavilion
Agriculture Building
Lewis Hall
Hamilton Hall
Herrick Hall
TABLE IV-a - FUSE CUTOUTS
Quantity
2
2
5
2
3
3
3
5
2
3
2
3
3
2
3
I
3
2
2
5
7
I
Type
Rating
Voltage
Current
2500
OD
OD
E
OD
9 f 6a i 4
9F6 a i 4
OD
ES
OD
E
E
ES
OD
OD
ES
ES
E
E
ES
OD
7500
7500
5000
7500
5000
5000
7500
5000
7500
5000
5000
5000
7500
7500
5000
2500
5000
5000
5000
5000
7500
2500
30
30
30
60
30
50
50
30
50
30
60
50
50
30
30
50
30
50
50
50
50
30
30
amp
amp
amp
amp
amp
amp
amp
amp
amp
amp
amp
amp
amp
amp
amp
amp
amp
amp
amp
amp
amp
amp
amp
Manufacturer
Westinghouse
Weetinghouse
Westlnghouse
General Electric
Westlnghouse
General Electric
General Electric
Westinghouse
Westlnghouse
Westinghouse
General Electric
General Electric
Westinghouse
Westlnghouse
Westinghouse
Westinghouse
Westinghouse
Westlnghouse
General Electric
General Electric
Westlnghouse
Westlnghouse
Westinghouse
Location
Stock Pavilion
Hamilton Hall
Gymnasium
Gymnasium
Heating Plant
Heating Plant
Physics Building
Robert’s Hall
Student Union
Chemistry Building
Music Building
Lewis Hall
Agriculture Building
Lewis Hall
Montana Hall
Herrick Hall
Herrick Hall
Quadrangle
Quadrangle
Girl’s Quonsete
North Barracks
Ryan Laboratories
Ryaui Laboratories
63
TABLE V - HIGH VOLTAGE EQUIPMENT IN THE TRANSFORMER VAULTS
AGRICULTURE BUILDING
2 Westinghouse, type S, IO Kva transformers
I Westinghouse, type I, oil switch
3 Westinghouse, type ES, fuse cutouts
CHEMISTRY BUILDING
I Vi/estinghouse,
1 Westinghouse,
2 Vjestinghouse,
3 Westinghouse,
type
type
type
type
8, 15 Kva transformer
S, 50 Kva transformer
F l O , automatic oil circuit breakers
GD, fuse cutouts
GIRL'S QUONSETS
1 Westinghouse, type S, 25 Kva transformer
2 General Electric, type E, fuse cutouts
GYMNASIUM
2 Westinghouse, type S,
Kva transformers
I Westinghouse, type S, 25 Kva transformer
1 General Electric, type HS, 25 Kva transformer
2 Westinghouse, type F10, automatic oil circuit breakers
5 Westinghouse, type OD , fuse cutouts
2 General Electric, type E, fuse cutouts
HAMILTON HALL
1 Westinghouse,
2 Westinghouse,
I Westinghouse,
1 Westinghouse,
2 Westinghouse,
type
type
type
type
type
S, 25 Kva transformer
F10, automatic oil circuit breakers
H, automatic oil circuit breaker
I, oil switch
OD, fuse cutouts
HEATING PLANT
2 Westinghouse, type S, 10 Kva transformers
2 General Electric, type H, 10 Kva transformers
2 Westinghouse, type H, automatic oil circuit breakers
3 Westinghouse, type OD, fuse cutouts
3 General Electric, type 9F6A14, fuse cutouts
HERRICK HALL
3 Westinghouse, type S, 50 Kva transformers
I Westinghouse, type Fl0, automatic oil circuit breaker
I Westinghouse, type I, oil switch
3 Westinghouse, type ES, fuse cutouts
6 Westinghouse fuse cutouts
64
TABLE V - (Continued)
HUDSON HOUSE
I General Electric, type HS, 25 Kva transformer
I Kitestinghouse, type S, 75 Kva transformer
LEWIS HALL
I Kestinghouse, type S, I^ Kva transformer
I General Electric, type H, 15 Kva transformer
I Vvestlnghouse, type S, 25 Kva transformer
5 Vvestinghouse, type H, automatic oil circuit breakers
1 Weetinghouee, type I, oil switch
2 Westinghouse, type GD, fuse cutouts
3 General Electric, type E, fuse cutouts
MONTANA HALL
I Vvestinghouse,
I Vvestinghouse,
I Vvestinghouse,
I Vvestinghouse,
3 VVestinghouse,
type
type
type
type
type
S, 10 Kva transformer
S, 15 Kva transformer
FlO, automatic oil circuit breaker
H, automatic oil circuit breaker
GD, fuse cutouts
MUSIC BUILDING, M E N ’S QUONSETS, CHEMISThY ANNEX
1 Vvestinghouse, type S, 25 Kva transformer
2 General Electric, type E, fuse cutouts
NOhTH BAhhACKS, WOOL LABORATORY, MILITARY BUILDINGS
2 General Electric, type H, 10 Kva transformers
I vvestinghouse, type S, 10 Kva transformer
I Kulnman Electric, type OISC, 75 Kva transformer
5 Vvestinghouse, type ES, fuse cutouts
PHYSICS BUILDING
I General Electric, type HSA, 7-| Kva transformer
I General Electric, type HS, 25 Kva transformer
3 General Electric, type 9F6A14, fuse cutouts
QUADRANGLE
2 Vvestinghouse, type S, 25 Kva transformers
1 vvestinghouse, type S, 37^ Kva transformer
3 vvestinghouse, type ES, fuse cutouts
2 General Electric, type E, fuse cutouts
ROBEhT'S HALL
2 Vvestinghouse,
1 Vvestinghouse,
2 Vvestinghouse,
5 Vvestinghouse,
type
type
type
type
S, 3 Kva transformers
S, 50 Kva transformer
H, automatic oil circuit breakers
On, fuse cutouts
65
TABLE V - (Continued)
RYAN LABORATORIES
5 inestinghouse, type S, 5 Kva transformers
I General Electric, type H S A , 7-g- Kva transformer
1 tiestinghouse, type S, IO Kva transformer
2 Westlnghouse, type S, 50 Kva transformers
1 Viestlnghouse, type F10, automatic oil circuit breaker
2 Westlnghouse, type H, automatic oil circuit breakers
7 Westlnghouse, type OD, fuse cutouts
I Westlnghouse fuse cutout
STOCK PAVILION
I Westlnghouse, type S, 25 Kva transformer
I Westlnghouse, type P’10, automatic oil circuit breaker
1 Westlnghouse, type I, oil switch
2 Westlnghouse fuse cutouts
STUDENT UNION BUILDING
1 Westlnghouse, type S, 50 Kva transformer
2 Westlnghouse, type F10, automatic oil circuit breakers
2 Westlnghouse, type ES, fuse cutouts
MONTANA STATE UNIVERSITY LIBRARIES
4573 7
762
N378
J62p cop,2
893L2
Johns, David G,
S b m c analysis sf "the Montana
State College 2300 volt power
system.
a - 3-43»
Fr IAJ. (S n / S V &
£// So./tf*#/
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