®
®
®
DEHN, Inc.
Technical Presentation
© 2014 DEHN, INC.
1
®
®
®
DEHN, Inc.
Technical Presentation
Effective Installations of AC & DC Power
Surge Protective Devices (SPD)
© 2014 DEHN, INC.
2
Presenter
®
Frank Basciano
 USA Product Manager; Sr.
Application
pp
Engineer
g
 26 years in industry
– In 7th year with DEHN
 Eaton/Cutler-Hammer
E t /C tl H
– Product Manager
– Power Quality Division
 Innovative Technology, Inc.
–
–
–
–
–
Director of Product Mgmt
Director of Engineering
Director of Operations
Design Engineer
Quality Engineer
© 2014 DEHN, INC.
 IEEE Member
 IEEE SPD Standards Committee
 IEC SC37 SPD St
Standards
d d C
Committee
itt
3
®
®
®
The Nature of Lightning
© 2014 DEHN, INC.
4
Slow Motion Lightning Event
© 2014 DEHN, INC.
®
5
Lightning
g
g strike, Dubai 2010 –
Not highest nearby point
© 2014 DEHN, INC.
®
6
Some Lightning Facts
®
1 Lightning is NOT a single stroke
1.
stroke, 4 -17
17 strikes in one
event!!
2. Lightning does NOT always hit the highest point!!
3. Lightning does NOT need a metal conductor – it uses
air, it likes trees and the earth itself!!
4 There is a higher probability that Lightning will strike
4.
high metal objects over other materials or places.
© 2014 DEHN, INC.
7
Lower 48 Distribution of Lightning
© 2014 DEHN, INC.
®
8
National Weather Service – USA
© 2014 DEHN, INC.
®
9
Protect Yourself!
 Crouch down,
down do
NOT lie down
 Keep at least 3m
distance from
objects & people
 Put feet closely
together
 Wrap arms
around legs & tuck
your chin
© 2014 DEHN, INC.
®
Open Field Exposure
10
Lightning
g
g Damage
g
© 2014 DEHN, INC.
®
11
®
®
Power SPD Specifications &
Installations
“No matter
“N
tt who’s
h ’ product
d t you iinstall,
t ll if it iis
not isntalled well, all bets are off. The SPD will
not perform well or as expected
expected.”
Frank Basciano
© 2014 DEHN, INC.
12
SPD Company Specifications
®
SPD ratings
 Are the values tested by third party?
– IEC standards are performance & safety standards
– Therefore, if IEC certified by third party (KEMA), then results are
verified, like DEHN
Peak Surge Current
 Inflated Numbers
 Additive Rule (per phase, per mode)
 Often not tested values
 When tested,
tested numbers given are typically best case,
case DEHN
publishes worst case
© 2014 DEHN, INC.
13
Maximum Surge Capability:
Limited by Electromechanical Connections
®
AC P
Protector
t t R
Rated
t d ffor 85 kA
kA, 8/20 µs
Connector blew
off
ff at
20 kA, 8/20 s
© 2014 DEHN, INC.
14
Maximum Surge Capability:
Limited by Printed Circuit Design
®
AC Protector Rated for 100 kA,, 8/20 µs
Neutral trace
vaporized at
18 kA 8/20
/ s
© 2014 DEHN, INC.
15
Maximum Surge Capability:
Limited by SPD Internal Fusing
®
AC Protector Rated for 160 kA, 8/20 µs
Fuse opened
p
at
8 kA 8/20 s
© 2014 DEHN, INC.
16
Summary on Specifications
®
IEC Tested Products – values are verified by Third-Party
Third Party Lab
UL does NOT test “peak
peak surge current
current”
UL only assigns VPR and verifies Nominal Discharge Current
© 2014 DEHN, INC.
17
National Electric Code – 2014
SPD Installations
®
Article 285
285.5 – Listed - An SPD shall be a listed device.
Which one is “Listed”?
© 2014 DEHN, INC.
18
“Listed” per 2014 NEC Definition
®
Listed.
Equipment, materials,
Equipment
materials or services included in a list published by
an organization that is acceptable to the authority having jurisdiction and
concerned with evaluation of products or services, that maintains periodic
i
inspection
ti off production
d ti off listed
li t d equipment
i
t or materials
t i l or periodic
i di
evaluation of services, and whose listing states that either the equipment,
material, or service meets appropriate designated standards or has been
tested
d and
d found
f
d suitable
bl for
f a specified
f d purpose.
Informational Note: The means for identifying listed
equipment may vary for each organization concerned with
product evaluation, some of which do not recognize equipment
as listed
li d unless
l
it
i is
i also
l labeled.
l b l d Use off the
h system
employed by the listing organization allows the authority
having
g jurisdiction
j
to identify
fy a listed product.
p
© 2014 DEHN, INC.
19
Bottom Line on “Listed”
®
A th it H
Authority
Having
i
JJurisdiction
i di ti
AHJ
© 2014 DEHN, INC.
20
2014 NEC® - SPD Installation
®
285.12
285
12 Routing of Connections
Connections. The conductors used to
connect the SPD to the line or bus and to ground shall not
be anyy longer
g than necessaryy and shall avoid unnecessaryy
bends.
The intent of this article is for Parallel Wired SPD
Series Wired SPD we don’t care about lead length
© 2014 DEHN, INC.
21
®
®
®
Installation
Practices
Examples of Good and Poor Installations – and why it‘s bad
Form, Fit & Function
© 2014 DEHN, INC.
22
SPD Installation Practices
®
Nobody sets out to create a
poor or bad SPD install!!!
p
What you don’t know, you
don’t know.
© 2014 DEHN, INC.
23
Two Basic SPD Styles = Form
®
Wired in Parallel = most
common
Wired in Series
1
1.
Most common
1
1.
More difficult install
2.
Most misunderstood
2.
Limited Current, limited use
3.
Most problems with correct
3.
Terminal & product heat
install
buildup
4.
Easiest to install
4.
People think power filter
5.
p think “gray
g y box”
People
5.
SCCR coordination issue
6.
SCCR coordination issues
6.
Few problems SPD installs
7
7.
Large for mains use
© 2014 DEHN, INC.
24
How do these things get into our systems
Parallel Wiring
© 2014 DEHN, INC.
®
Series Wiring
25
Installation Practices = Fit
®
Parallel Products
 Typical installs are usually not good for lightning & surge
protection
 Lead Length Matters!!!
– Longer
g Lead Length
g decreases performance
p
– Often makes the SPD ineffective
 Wire Dress matters – not in the way you think!!
– Neat
N t is
i nott always
l
b
bestt for
f SPD performance
f
 Increases LTV (MLV)
– Odds of downstream equipment
q p
failure increase
– Not what you paid for
– Equipment & facility – NOT protected!
© 2014 DEHN, INC.
26
Parallel Installations
®
Typical USA Installation
 Three Phase Wye
 Distribution Panel
 Neat on the outside
 Don’t
D ’ kknow about
b
the
h iinside
id
 Where is the ground bar usually?
 Do you see anything wrong or
inefficient in the installation?
© 2014 DEHN, INC.
27
Installation Comparison
p
with lightning
g
g currents
© 2014 DEHN, INC.
®
28
Electrodynamic Forces - (EMF)
®
Si
Simplified
lifi d Calculation
C l l ti – Force
F
in
i N/
N/m
Remember this as we proceed
through the next slides.
slides
© 2014 DEHN, INC.
29
Not too bad of an install – Long Leads
But could have been made better!!
© 2014 DEHN, INC.
®
30
Not too bad of an install – Long Leads
But could have been made better!!
®
Big boxes make
for difficult
installs this size
installs,
SPD is too much.
A series wired
install would have
improved this SPD
performance.
© 2014 DEHN, INC.
31
Poor Install
Too long of a ground wire
© 2014 DEHN, INC.
®
32
Poor Install – Long Leads
Did a few things right – perpendicular wires!
© 2014 DEHN, INC.
®
33
Poor Installation:
Excessive Lead Length
®
US West Co. - Council
Bluffs, Iowa
Switchgear
Protected by
Surge
Protector
© 2014 DEHN, INC.
AC Surge
P
Protector
34
®
NEC 110
110.13
13 and 110
110.14
14
violations and 285.12
© 2014 DEHN, INC.
35
Poor Wire Dress,
Ineffective SPD due to installation
®
Wire tie wrapped,
but unnecessarily long
© 2014 DEHN, INC.
36
Poor Installation:
Disconnect adds excessive lead length
®
Panel
Protected
by Surge
Protector
AC Surge
Protector
© 2014 DEHN, INC.
Disconnect
for Surge
Protector
37
Function
Wire Length – IEEE, Guide to Surge Protection
Wire Voltage Drop:
VL = L(di/dt) + (IL * RL)
© 2014 DEHN, INC.
®
VL – Voltage drop of wire
IL – current through the wire
RL – resistance of length of wire
di/dt – change of current over change of time
L – inductance of wire length
38
Installed Let Through Voltage
®
Surge Protector + Connecting Leads
© 2014 DEHN, INC.
39
Influence of the connecting leads on the real
protection level
®
L/N
Udynamic 1
isurge
Uprospection
Udynamic 1+
Utotal = Uprospection +
Udynamic 2
Udynamic 2
PE
Udynamic = ((i • R)) + (di/dt)
(
)L
© 2014 DEHN, INC.
40
Calculated Wire Voltage Drop
5 ft,, 1/0
/ AWG Connection Leads
Applied Surge = 30 kA, 8/20 µs
®
Wire Voltage Drop:
VL = L(di/dt) + (IL * RL)
(IL * RL) = 30 kA x 5 ft x 0.1 mΩ/ft
= 15 volts
L (di/dt) = 5 ft x 0.4 μH/ft x (30 kA / 8 μs)
= 2 μH
H x 3.75
3 75 x 109 A/s
A/
= 7,500 volts (7.5 kVpk)
V is approximately 7,515 volts peak
© 2014 DEHN, INC.
41
5 ft, 1/0 AWG Connection Leads
10 kA, 8/20 µs
®
Dead Short - 5 ft,1/0
f
AWG - 6 in. separation
Let Through
2,140 Volts
© 2014 DEHN, INC.
42
5 ft, 1/0 AWG Connection Leads
10 kA, 8/20 µs
®
Dead Short - 5 ft
1/0 AWG - with wire
ties
Let Through
1 280 Volts
1,280
© 2014 DEHN, INC.
43
Influence of the connecting leads on the real protection level
Laboratory testing - Low impulse current 5 kA 8/20 µs
®
DEHNguard 275 Lead length
Equivalent circuit diagram
Generator
30 kV
1
Up
0m
A
5 kA (8/20 µs) 0.3 m
Test setset-up
© 2014 DEHN, INC.
Connecting
g lead
44
1m
2m
Influence of the lead length on the real protection level
Lab testing - Low impulse current 5 kA 8/20 µs
Test result
®
6 i [kA]
Up [kV] 3.0
Surge current 5 kA (8/20µs)
2.5
5
Protection level
2 meter lead length
1 meter lead length
0,3
0 3 meter lead length
"ideal" connection
2.0
1.5
15
3
1.0
2
0.5
1
0.0
0
-0.5
0
© 2014 DEHN, INC.
4
5
10
15
20
25
30
35
40
-1
45 50
time t [µs]
45
Influence of the lead length on the real protection level
Lab testing - Increased impulse current 15 kA 8/20 µs
®
Surge current 15 kA (8/20 µs)
Test result
Up [kV]
16
4.0
14
3.5
12
Protection
P t ti
level
l
l
3.0
1 meter lead length
2.5
0.3 meter lead length
2.0
"ideal"
"id l" connecting
ti
8
6
1.5
4
1.0
10
2
0.5
0
0.0
00
-2
-0.5
-1.0
0
10
-4
5
10
15
20
25
30
35
40
45
50
time t [µs]
© 2014 DEHN, INC.
46
i [kA]
Summary Graphic
© 2014 DEHN, INC.
®
47
So, how long is acceptable?
®
No USA standard – ugh! The NEC is the best we have now.
now
However there is an IEC standard (no surprise)
However,
IEC 60364-5-53/A2
60364 5 53/A2
" ... increasing the length of connecting conductors of SPDs reduces
the effectiveness of overvoltage protection“
“ ... Optimum
p
overvoltage
g protection
p
is achieved when all connecting
g
conductors of SPDs are as short as possible“
© 2014 DEHN, INC.
48
Influence of the connecting leads on the real
protection level
®
IEC 60364-5-53/A2- Installation requirements:
q
Connecting
g leads
a+b  0.50 m
a
S
P
D
b  0.50 m
S
P
D
E/I
E/I
b
b
EBB
© 2014 DEHN, INC.
EBB
49
Installation of SPDs in stub-wiring
Parallel Installation
®
L1´
L2´
L3´
PEN´
Input
O t t
Output
Service
Entrance
Box
DEHNport Maxi
SPD
No. 900 104
L1 L2 L3 PEN
Service cable
© 2014 DEHN, INC.
B
UC
IImp
255 V ~
50 kA (10/350)
Up
4 kV

DEHNport Maxi
SPD
No. 900 104
B
UC
IImp
255 V ~
50 kA (10/350)
Up
4 kV

DEHNport Maxi
SPD
No. 900 104
B
UC
IImp
255 V ~
50 kA (10/350)
Up
4 kV

EBB
50
Technical solutions to reduce the dynamic
voltage drop across the connecting leads
®
INPUT
OUTPUT
L1´
L2´
L3´
PEN´
HAK
L1 L2 L3 N
Power Supply
EBB
Serial connection of the lightning current arrester = Reduction of the lead lengths
© 2014 DEHN, INC.
51
Technical solutions to reduce the dynamic
voltage drop across the connecting leads
®
L1´
L2´
L3´
N´
PE´
OUTPUT
INPUT
HAK
DEHNventil ® TT
Coordinated-SPD
B
DEHNventil ® TT
D
No. 900 375
Uc
IImp
Up
255 V ~
25 / 100 kA ((10/350))
 1,5 kV (L-N/N-PE)
315 A (L)
125 A (L-L´)
L1
L2
L1´

H1

L2´
L3

H2

L3´
N

H3
N´



PE
Power
pp y
Supply
L1 L2 L3 N
EBB
- Double terminals for serial connection: Avoiding any dynamic voltage drop
- Additional earth terminal: Avoiding dynamic voltage drop and current distribution between multiple
conductors
© 2014 DEHN, INC.
52
®
Series Wired Installation
Parallel SPD using
g the built in
terminals like the previous
slide
© 2014 DEHN, INC.
53
How to make it better!
®
1
1.
Twist phase wires together
2.
Cut and bond ground wire
directly to the panel using a
lug listed for that
purpose,allowed by NEC
285 28 this will shorten this
285.28,
lead considerably, remember,
≈100 Vpk/inch degradation
Downsides:
At the bottom of the panel,
panel
transient voltage must travel
down the bus to the bottom
b f
before
it sees the
th SPD!
© 2014 DEHN, INC.
54
City of Orlando & Clearwater Installs
Good Installs
© 2014 DEHN, INC.
®
55
Good Install
© 2014 DEHN, INC.
®
56
Good Install
© 2014 DEHN, INC.
®
57
MCC #1 install City of Orlando, Lift Station,
480 wye, no neutral – Good Install
© 2014 DEHN, INC.
®
58
Summary – Simple Rules
®
1 Keep the overall length of phase conductors short – cut
1.
them! Twist the phase conductors together!!
2. Use high strand count wire – 133 strands or more
(welding cable)
3. Use largest gauge wire possible – recommend 6 AWG
4 Avoid any sharp bends
4.
bends, if must bend make the bend a
large radius
The above is in order of importance!!
© 2014 DEHN, INC.
59
®
®
®
Questions &
Further Discussion
© 2014 DEHN, INC.
60
®
®
Thank you for attending
© 2014 DEHN, INC.