Power
Supply
Center™
FOR
LOW VOLTAGE
LIGHTING
FEATURES
OPTIMAL LIGHTING PERFORMANCE
QUIET OPERATION
RECESSED OR SURFACE MOUNT
ZERO CLEARANCE INSTALLATION
SIMPLE TO INSTALL
QUALITY CONSTRUCTION
BENEFITS OF A MULTI-VOLT Power Supply Center™
Bad
Bad
Bad
Good
Excellent
Light
Output
47%
57%
69%
85%
100%
Lamp Volts
19.2 V
20.4 V
21.6 V
22.8 V
24.0 V
-20%
-15%
-10%
-5%
0%
9.6 V
10.2 V
10.8 V
11.4 V
12.0 V
47%
57%
69%
85%
100%
Bad
Bad
Bad
Good
Excellent
Voltage Drop
Lamp Volts
Light
Output
Rating
THE TRANSFORMER’S
ROLE IN THE
PERFORMANCE OF LOW
VOLTAGE LAMPS:
ASSET VS. LIABILITY
24V LOW VOLTAGE LIGHTING
22.1 V
20.6 V
75%
23+ V
60%
90 -100%
D
Bad
Bad
T
90 -100%
S
120 V
120 V
120 V
D
112 V
S
120 V
23+ V
120 V
VOLTAGE DROP ON
LIGHT OUTPUT:
Rating
110 V
THE IMPACT OF
General Purpose lighting transformers do not operate Low Voltage Lighting at optimum light output
levels. Low Voltage Power Supply Centers (PSC), developed and manufactured, are the first
transformer systems specifically designed for today’s low voltage lighting and its unique installation
requirements. The heart of the PSC system is a Toroidal Multi-Volt Transformer. A Toroid is known for its
small size, superior voltage regulation, quiet operation, high efficiency, cool operating temperature and
its ability to take the stress of dimming.
120 V
PERFORMANCE
MAKES THE
DIFFERENCE
Excellent
T
Excellent
L
L
12V LOW VOLTAGE DOWN LIGHTS
INTEGRAL TRANSFORMERS
T 10.3 V
10.8 V
9.8 V
11.6 V+
11.6 V+
112 V
120 V
T 11.4 V
KEY
69%
50%
Bad
T
90 -100%
90 -100%
Excellent
Bad
T
120 V
110 V
Bad
D
120 V
120 V
60%
S
120 V
112 V
120 V
85%
Good
D
120 V
120 V
S
D
120 V
S
L
Excellent
L
S = SWITCH
D = DIMMER AT FULL BRIGHT
T = GENERAL PURPOSE TRANSFORMER
L = Litelab MULTIVOLT TOROIDAL TRANSFORMER
REMOTE TRANSFORMERS
11.5 V GENERAL
PURPOSE TRANSFORMER
REMOTE TRANSFORMERS
12.3, 13.3, 14.3, OR 15.3 VOLT OUTPUT
TOROIDAL DESIGN BY Litelab
MULTI-VOLT = PERFORMANCE
The PSC Multi-Volt feature allows it to adapt to every field condition,
ensuring that proper voltage is received at the lamp. The diagram below
shows the voltage available from both PSC Multi-Volt Toroidal
Transformer and General Purpose transformers.
NO LOAD
FULL LOAD
300W
100W
0
100W
0
600W
600W
VOLTS
i3.0
PSC Multivolt
Toroidal Transformer
Typical Single Volt
Genreal Purpose
Transformer
i4.0
i5.0
400
W
0W
0W
50
20
400
W
0W
0W
50
20
300W
i2.3
i3.3
i4.3
i5.3
OR
26.0 28.0 30.0 32.0
24.6 26.6 28.6 30.6
OR
While 24 volt lighting operates at 1/5th the voltage of 120
systems and 12 volt lighting at l/lOth of line voltage, it also
operates at 5 to 10 times the amperage. Avoid overloading the
secondary wiring by using the correct American Wire Gauge
(AWG) sized to the secondary circuit breaker. Wire gauge and
wattage for each circuit breaker is shown below and on the
Voltage Drop Calculator.
THREE KEY POINTS
TO KNOW:
AWG AMPS
#14
15A
12V
180W MAX
#12
20A 240W MAX
1. Voltage of fixture
#10
25A 300W MAX
2. Amperage or
wattage rating of fixture
3. AWG recommended for fixture & installation
24V
360W MAX
480W MAX
600W MAX
VOLTS
i6.0
OR
i2. i
1WIRE FOR SAFETY FIRST
24.2
i i.5
OR
SECONDARY CIRCUIT BREAKER TABLES: 12V & 24V
150W Max.*
1 - 15A
2 - 15A
1 - 15A
300W Max.*
1 - 20A
1 - 15A
23.0
NO FIXTURE NOISE WITH
REMOTE TRANSFORMERS
Removing the transformer from the light fixture and remote mounting
transformers is the only way to guarantee a noise free installation. The
PSC Multi-Volt feature will allow for proper voltage to the fixtures, while
permitting smaller ceiling openings and decreasing fixture maintenance
due to transformer heat.
SAFETY SAFETY SAFETY
The Power Supply Center is provided with three levels of circuit
protection.
PRIMARY
Magnetic Circuit Breaker
TRANSFORMER Thermal Auto Reset Breaker
SECONDARY
Magnetic Circuit Breaker(s)
Furthermore, the PSC is UL listed as an Inherently Protected IC Power
Supply. This unique listing permits zero clearance to combustible materials.
This allows installation in contained areas, including closets where items
may come in direct contact with the PSC without risk of fire hazard.
LABOR SAVINGS
The PSC is listed for surface or recessed wall mounting. The added
flexibility of mounting in a wall and in a contained area allows the PSC
to be mounted much closer to the load. This ability will reduce labor and
material costs. The Power Supply Center comes with four output voltages
to assure full voltage at the lamp. Confidence is the key word spoken
over and over again by contractors using the PSC. The contractor knows
from the beginning that at the end of the job the lighting will operate
correctly. Best of all, everything required is contained in a PSC.
1 - 25A
600W Max.*
4 - 15A
2 - 15A
2 - 20A
1 - 20A
2 - 25A
1 - 25A
*Load
should not
exceed
transformer
capacity.
2 SEPARATE RUNS
A few important reasons for separate feeds:
2A Some remotely powered lighting fixtures are required by
UL to have separate feeds from a transformer. These
fixtures are not permitted to be installed by through wiring
from one fixture to another. Thus, each fixture must have a
separate pair of wires terminating at the PSC.
For example: a 12V - 750 watt Power Supply running
15 - 50W lamps should have 15 separate feeds of
equal gauge and length running back to the PSC.
(SEE 4A)
2B Each 12V - 50W lamp is rated at 4.2 amps
(50W ÷ 12V = 4.2A). Through wiring fixtures, the
amperage would go from 4.2A to 8.4 to 12.5 to 16.7 to
20.8 to 25.0 to 29.2 quickly exceeding (in most cases)
the secondary wire rating. As the amperage increases,
the secondary voltage would decrease and each lamp
would produce lower light levels. It is very important that
all fixtures receive the same voltage to assure that light
output is equal.
2C You must balance or equalize the loads (watts) of each
run so that each run receives the same voltage.
RECOMMENDED WIRING METHODS:
QX 600 MV - 24 - 4X15 (6 Feed Loads)
QX 600 MV - 12- 4X15 (12 Feed Loads)
QX 600 MV - 12 - 4X15 (4 Feed Loads)
#14 TYP.
#10
4B
4A
4C
#10
#10
#10
#10
#14
#12
#12
#14
EQUAL GAUGE & EQUAL LENGTH
EQUAL LOAD & EQUAL GAUGE & EQUAL LENGTH
BALANCE LOAD THEN VARY GAUGE OF WIRE
TO LOAD & DISTANCE PER LV CALCULATOR
NEVER THRU-WIRE LOW VOLTAGE DOWNLIGHTS OR LOW VOLTAGE STRIPS!
5 PSC MULTI-VOLT FEATURE
3 WHY VOLTAGE DROP
The PSC transformer is made with four taps on the primary
winding. These taps increase the output of the Secondary voltage.
The two columns of information on the Voltage Drop Calculator allow
for different input voltages: 120V for a switch and 110V for a dimmer
and optional choke.
When compared to a 120 volt system, 12 volt systems have a
10 fold increase in amperage. Longer wire runs translate into greater
voltage drop due to wire resistance which impacts light output and
color if not corrected. The Voltage Drop Calculator created by Litelab
indicates the maximum wiring runs for individual home runs. To
compensate for any voltage drop, an increased wire gauge can be
used and/or a different tap of the PSC Multi-volt feature can boost the
secondary output voltage.
The combination of proper length wiring runs, and wire sizing, along
with the correctly chosen multi-volt tap will insure optimal lighting
output to even the farthest fixture.
4 EQUALIZING VOLTAGE DROP
TEN VARIABLES OF LOW VOLTAGE LIGHTING
When installing multiple fixtures powered from a single remote
transformer, it is important to have the same wire resistance to all of
the connected fixtures. Installations that have different length wire runs
to each fixture will have voltage variations and could have noticeable
differences in light output. The way to avoid voltage drop variations
are described below.
4A
1
2
3
4
5
6
7
8
9
10
EQUAL GAUGE - EQUAL LENGTH:
It is recommended that all secondary wire runs be the same wire
gauge and same length. A common installation would usually require
some individual wire runs to have surplus wire. The installer should
staple or tie this excess wire in long loops (not coiled) to any
convenient hidden mounting surface. As an example, ten 75W
fixtures connected to a PSC with the furthest fixture is 50' away, cut
10 pieces of #14 AWG wire 50' long. Therefore, each lamp will
receive exactly the same voltage and have the same light output.
4B
GAUGE VARIATION:
4C
CONDUIT ALTERNATIVE:
6 FINAL ADJUSTMENTS
It is important to follow the
PRIMARY
12
24
guidelines previously suggested and
TAPS
VOLT
VOLT
to always check the lamp voltage at
BLACK
12.3 V
24.6 V
the end of an installation to be sure
GREY
13.3 V
26.6 V
the correct primary tap has been
ORANGE
14.3 V
28.6 V
RED
15.3 V
30.6 V
chosen. Please note that when
checking the voltage of a dimmed
circuit, a True Root-Mean-Squared (RMS) volt meter is required to
take proper voltage readings due to the sine wave distortion created
by electronic dimmer.
The Voltage Drop Calculator shows how the Multi-volt feature allows
you to vary the Secondary voltage and/or the wire gauge to the
load to compensate for voltage drop. Please note that there are two
columns of information: one for an on/off switch and the other
for a dimmer.
For non-dimmed conduit
installations with fixtures listed for
thru-wiring with a 50W max. lamp,
feed multiple fixtures from a feed
load. For proper results, balance
loads so voltage is 12V at the
center of all 3 lamp groups and a
max. of 6' of #10 AWG run to
outboard lamps. There still may be
a slight difference in light output.
Primary Voltage
Efficiency of the Dimmer or Switch
Efficiency of the Choke Design
Efficiency of the Transformer Design or Regulation
Manufacturing Tolerance of the Transformer & Choke
Resistance of the Circuit Breaker(s)
Total Load on the Transformer
Size of the Secondary Feed Load
Size of Secondary Wire Gauge to Feed Load
Length of the Secondary wire to Feed Load
Bad
Excellent
Bad
Volt Reading
Taken at Lamp
True RMS
Volt Meter
When Dimmed
I0.2I
I I.0I
I I.86
Black Tap
Grey Tap
Orange Tap
WHIT
Litelab MULTI-VOLT
TOROIDAL
TRANSFORMER
Only Primary
Taps Shown
WH
ITE
BLACK
E
WHIT
PRIMARY
BLACK
WH
E
ITE
BLACK
GREY
GREY
OR
AN
GE
RE
D
OR
AN
GE
RE
D
PRIMARY
BLAC
K
WHIT
WH
E
ITE
BLACK
GREY
OR
AN
GE
RE
D
PRIMARY
BLA
CK
Power Supply Center™ ORDERING INFORMATION AND SPECIFICATIONS
LOW VOLTAGE LIGHTING
POWER SUPPLY CENTER
SPECIFICATIONS
Hinge Bracket
Primary
Taps
Ground Wire
Secondary
Breakers
Primary
Breaker
ON
ON
TYPE:
PROJECT:
ON
Snap
Caps
Multivolt Toroidal
Transformer
Screw &
Cover Cap
7"
8"
NOTES:
AL
ITT GE
M
A
B
SU PY P E
R
O
FO O C BLU PY)
TO CO
OT
PH (PHONOT
Optional
Choke
Secondary Leads
14.25"
15.75"
Housing - Front View
Door - Front View
Housing - Top View
Housing - Bottom View
WI
3.875"
LL
HOUSING:
18 gauge welded steel measuring 14.25"L x 7.00"H x 3.875"D with 18 knockouts. Built-in
support bracket incorporated for securing housing to a 2 x 4 wall stud for recess wall mounting.
PRIMARY CIRCUIT:
Protected by a magnetic circuit breaker of appropriate size per the N.E.C. Article 450-3(b).
All wiring by the electrical contractor must be Class 1 compliant N.E.C.
SECONDARY CIRCUIT:
HINGED BRACKET OPEN (RECESSED MOUNTED)
Protected by color coded magnetic circuit breaker(s) (15A, 20A or 25A) appropriately sized
to the Feed Load per 1996 N.E.C. Article 411(not to exceed 25 Amps per load).
All wiring by the electrical contractor must be Class 1 compliant N.E.C.
TRANSFORMER:
Protected by an auto re-set thermal circuit breaker mounted internally and connected to the
white common primary lead.
MULTI-VOLT TOROIDAL TRANSFORMER:
Four taps on the primary winding to produce the following nominal voltages on the
Secondary side: 12, 13, 14 & 15 volts or 24, 26, 28 & 30 volts. The splice area has more
than 125 cu. in. of useable space and can incorporate an optional choke for dimming.
CHOKE & CIRCUIT BREAKERS:
HINGED BRACKET CLOSED (SURFACE MOUNTED)
NOTE: Manufacturer reserves the right to
make product specification changes without
prior notice.
Mount to an internal hinge bracket. This hinge bracket is designed to swing out to permit easy
access to the splice compartment.
DOOR:
Measures 15.75"L x 8.00"H. Made of .090 aluminum. Slots in the door are
positioned over circuit breakers to allow resetting without door removal.
ORDERING FORMAT FOR QX SERIES
Low Voltage Fixture
Power Supply Center
■
■
■
■
■
■
■
■
Surface mounting - wall or ceiling
Recessed mounting - wall only
Inherently Protected
Suitable for use in insulated
spaces - zero clearance.
Suitable for use in closets
with clothes in direct contact.
Suitable for Damp Locations
60 Cycle A.C. Only
Isolation Multi-Volt Toroidal
Transformer per NEC Article 411
2
WATTAGE
1
TRANSFORMER
PART NO.
XMV120/12
XMV230/12
XMV277/12
150
300
600
750
1
2
3
15
20
25
50
60
3
# CIR. BKRS
-
4
AMPERAGE
x
DESCRIPTION
120 volt primary to 12 volt output Multi-Volt Isolation Toroidal Transformer
230 volt primary to 12 volt output Multi-Volt Isolation Toroidal Transformer
277 volt primary to 12 volt output Multi-Volt Isolation Toroidal Transformer
150 watt output
300 watt output
600 watt output
750 watt output
3: NUMBER OF SECONDARY CIRCUIT BREAKERS*
One to three Secondary Circuit Breakers Can Be Used
4: AMPERAGE OF SECONDARY CIRCUIT BREAKERS*
Installation Instructions
SURFACE MOUNTING
RECESSED MOUNTING
1
Install housing in level position. Pull Rough-In wiring per instruction in
this brochure and in Voltage Drop Calculator/Rough-In Wiring Guide.
Remember that all Primary and Secondary wiring should be Class 1 per
the National Electric Code. Install (Optional) choke if shipped separately.
Install Secondary Circuit Breakers on the hinged panel, if not factory
installed, by first removing the snap cap covering the hole.
1
COLOR VOLTAGE
AMPS
AWG
12V
PURPLE Secondary
BLUE
Secondary
YELLOW Secondary
WHITE Primary
25A
#10
300W max
20A
#12
240W max
15A
#14
180W max
ALWAYS FACTORY INSTALLED
24V
600W max
480W max
360W max
2
3
Connect Primary and Secondary wires per wiring diagrams below.
Make sure all connections are tight.
After wiring and lamping all fixtures turn the power on (if dimmed, set
dimmer to full bright) and check voltage at the lamps. Adjust the output
voltage of the PCS by changing the transformer tap so lamps receive the
proper voltage. Remember to use a True-Root-Mean-Squared volt meter
when dimmed.
Install cover and snap screw cover caps closed.
2
4
3
1
2
3
Low Voltage Fixture Power Supply Center
Surface mounting - wall or ceiling • Recessed mounting - wall only
Inherently Protected • Suitable for use in insulated spaces - zero clearance.
• Suitable for use in closets with clothes in direct contact. • Suitable for Damp
Locations • 60 Cycle A.C. Only • Isolation Multi-Volt Toroidal Transformer
WIRING DIAGRAMS
4
4
12 VOLT SYSTEM
Colored taps change
the secondary voltage
LOAD
1
Pick
Brown
Black
(12.3 V)
Black
Gray
(13.3 V)
A Tap
Standard
120VAC
60Hz
2
J1
Optional
277VAC
3
4
J2
Orange
(14.3 V)
White
(Neutral)
White
B
ON
ON
C
ON
Secondary Circuit Breakers
LOAD
Colored taps change
the secondary voltage
Black
Pick
A Tap
Optional
277VAC
Black
(24.6 V)
Brown
1
2
3
4
Neutral
B
ON
ON
Terminal
Block
24 volt system
Gray
(26.6 V)
Orange
(28.6 V)
Red
(30.6 V)
White
A
Purple
ON
Blue
Primary
Circuit Breaker Choke (Optional)
LOAD
Terminal
Block*
Yellow
*TERMINAL BLOCK
150 W
None
300 W
2 Position (shown)
600 W
4 Position
120VAC
60Hz
ON
Q-TRAN Multivolt Transformer
150, 300, or 600 watt capacity
24 VOLT SYSTEM
Hot
D
Terminal
Block
12 volt system
Red
(15.3 V)
Neutral
A
Purple
ON
LOAD
Terminal
Block*
Yellow
Primary
Circuit Breaker Choke (Optional)
LOAD
Blue
*TERMINAL BLOCK
150 W
None
300 W
2 Position
600 W
4 Position (shown)
Hot
N.E.C. 1996 CODE - ARTICLE 411 (excerpted from)
LOAD
White
(Neutral)
Secondary Circuit Breakers
LIGHTING SYSTEMS OPERATING AT 30 VOLTS
OR LESS
411-1. Scope.
This article covers lighting systems operating at 30 volts or less
and their associated components.
411-2. Lighting Systems Operating at 30 Volts or Less.
A lighting system consisting of an isolating power supply
operating at 30 volts (42.4 Vpk) or less, under any load
condition, with one or more secondary circuits, each limited to
25 amperes maximum, supplying lighting fixtures and associated equipment identified for the use.
411-3. Listing Required.
Lighting systems operating at 30 volts or less shall be listed for
the purpose.
411-4. Locations Not Permitted.
Lighting systems operating at 30 volts or less shall not be
installed (1) where concealed or extended through a building
wall, unless using a wiring method specified in Chapter 3 or
(2) within 10 ft. (3.05 m) of pools, spas. fountains, or similar
locations, except as permitted by Article 680.
411-5. Secondary Circuits.
(a) Grounding. Secondary circuits shall not be grounded.
(b) Isolation. The secondary circuit shall be insulated from the
branch circuit by an isolating transformer.
(c) Bare Conductors. Exposed bare conductors and currentcarrying parts shall permitted. Bare conductors shall not be
installed less than 7 ft (2.2m) above the finished floor, unless
specifically listed for a lower installation height.
411-6. Branch Circuit.
Lighting systems operating at 30 volts or less shall be supplied
from a maximum 20-ampere branch circuit.
411-7. Hazardous (Classified) Locations.
Where installed in hazardous (classified) locations, these systems conform with Articles 500 through 517, in addition to this
article.
Q-TRAN Multivolt Transformer
150, 300, or 600 watt capacity
WARRANTY:
Power Supply Centers (PSC) are fully warranted for five years from date of shipment. This warranty covers only properly installed PSCs used under specified
conditions. Manufacturer will, at its option, repair or replace without charge, defective PSCs, provided they are returned to the factory and our inspection
determines the unit to be defective under the terms of warranty. Repair or replacement, as stated above, shall constitute the purchaser’s
exclusive warranty, which does not extend to in-bound freight, installation, labor or any other charges.