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50VL-C, 50VL-F: Installation Instructions
Manufacturer reserves the right to change, at any time, specifications and designs without notice and without obligations.
9
High-Voltage Connections
The unit must have a separate electrical service with a field-supplied,
waterproof disconnect switch mounted at, or within sight from the unit.
Refer to the unit rating plate, NEC and local codes for maximum
fuse/circuit breaker size and minimum circuit amps (ampacity) for wire
sizing.
The field-supplied disconnect may be mounted on the unit over the
high-voltage inlet hole when the standard power and low-voltage entry
points are used. See
for acceptable location.
See unit wiring label (
-
) and
making high voltage connections. Proceed as follows to complete the
high-voltage connections to the unit.
Single phase units:
1. Run the high-voltage (L1, L2) and ground lead into the control box.
2. Connect ground lead to chassis ground connection.
3. Locate the black and yellow wires connected to the line side of the
contactor.
4. Connect field L1 to black wire on connection 11 of the compressor
contactor.
A09066
Fig. 10 – High- and Control-Voltage Connections
5. Connect field wire L2 to yellow wire on connection 23 of the
compressor contactor.
Three-phase units:
1. Run the high-voltage (L1, L2, L3) and ground lead into the control
box.
2. Connect ground lead to chassis ground connection.
3. Locate the black and yellow wires connected to the line side of the
contactor.
4. Connect field L1 to black wire on connection 11 of the compressor
contactor.
5. Connect field wire L3 to yellow wire on connection 13 of the
compressor contactor.
6. Connect field wire L2 to blue wire from compressor.
Special Procedures for 208-V Operation
Control Voltage Connections
NOTE:
Do not use any type of power-stealing thermostat. Unit control
problems may result.
Use no. 18 American Wire Gage (AWG) color-coded, insulated (35°C
minimum) wires to make the control voltage connections between the
thermostat and the unit. If the thermostat is located more than 100 ft
(30.5 m) from the unit (as measured along the control voltage wires), use
no. 16 AWG color-coded, insulated (35° C minimum) wires.
Standard Connection
Locate the seven (eight for 3-phase) low voltage thermostat leads in 24
volt splice box. A gray wire is standard on 3-phase units for connection
to an economizer. See
for connection diagram. Run the
low-voltage leads from the thermostat, through the control wiring inlet
hole grommet (
and
), and into the low-voltage splice box.
Provide a drip loop before running wires through panel. Secure and
strain relief all wires so that they do not interfere with operation of unit.
If an accessory electric heater is installed, low voltage leads from heater
must be connected to factory supplied control leads from Indoor Fan
Board P4 connector.
NOTE:
If the unit 24V wires do not have a matching receptacle, cut the
24V wires from the electric heater plug, strip the ends, and wire nut
together to match the schematic connections. If the electric heater 24V
wires do not have a matching plug, cut the 24V wires from the unit
receptacle, strip the ends, and wire nut together to match the schematic
connections.
Factory wires are provided for electric heat staging W1 and W2 (W2 and
W3 on IFB). If room thermostat has only one stage of supplemental heat,
connect white and violet wires shown in
field wire.
Some electric heaters have four control wires (plus common wire).
Consult unit wiring diagram and electric heater wiring diagram for
additional details.
Ttransformer Protection
The transformer is of the energy-limiting type, however a direct short
will likely blow a secondary fuse. If an overload or short is present,
correct overload condition and check for blower fuse on Indoor Fan
Board. Replace fuse as required with correct size and rating.
CAUTION
!
UNIT COMPONENT DAMAGE HAZARD
Failure to follow this caution may result in damage to the unit being
installed.
1. Make all electrical connections in accordance with NFPA 70
(NEC) (latest edition) and local electrical codes governing such
wiring. In Canada, all electrical connections must be in
accordance with CSA standard C22.1 Canadian Electrical Code
Part 1 and applicable local codes. Refer to unit wiring diagram.
2. Use only copper conductor for connections between
field-supplied electrical disconnect switch and unit. DO NOT
USE ALUMINUM WIRE.
3. Be sure that high-voltage power to unit is within operating
voltage range indicated on unit rating plate. On 3-phase units,
ensure phases are balanced within 2 percent. Consult local
power company for correction of improper voltage and/or phase
imbalance.
4. Do not damage internal components when drilling through any
panel to mount electrical hardware, conduit, etc.
POWER
SUPPLY
FIELD-SUPPLIED
FUSED DISCONNECT
HIGH VOLTAGE
POWER LEADS
(SEE UNIT WIRING
LABEL)
EQUIP GR
CONTROL BOX
LOW-VOLTAGE
POWER LEADS
(SEE UNIT
WIRING LABEL)
W1
Y
G
R
C
WHT(W1)
YEL(Y)
GRN(G)
RED(R)
BRN(C)
THERMOSTAT
(TYPICAL)
3-PHASE SHOWN
1-PHASE USES
TWO POWER
LEADS
W2
VIO (W2)
SPLICE BOX
DH
BLU (DH)
GRA (Y2)
3-Phase
Only
WARNING
!
ELECTRICAL SHOCK HAZARD
Failure to follow this warning could result in personal injury or death.
Before installing or servicing system, always turn off main power to
system and install lockout tag. With disconnect switch open, move
black wire from transformer (3/16 in.)(4.8 mm) terminal marked 230 to
terminal marked 208. This retaps transformer to primary voltage of 208
vac.