Carrier 50VL---A - Manual (Page 10)

10
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
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
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.
! WARNING
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 Fig. 10 for connection diagram.
Run the low--voltage leads from the thermostat, through the control
wiring inlet hole grommet (Fig. 2 and 3), 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 Fig. 10
to second stage heat field wire.
Some electric heaters have four control wires (plus common wire).
Consult unit wiring diagram and electric heater wiring diagram for
additional details.
TRANSFORMER 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.
50V
L
--
A