Carrier 48ES---A - Manual (Page 12)

12
heating and air conditioning systems. Secure all ducts to
building structure.
7. Flash, weatherproof, and vibration isolate all openings in
building structure in accordance with local codes and good
building practices.
Step 10 — Install Electrical Connections
ELECTRICAL SHOCK HAZARD
Failure to follow this warning could result in personal
injury or death.
The unit cabinet must have an uninterrupted, unbroken
electrical ground. This ground may consist of an electrical
wire connected to the unit ground screw in the control
compartment, or conduit approved for electrical ground
when installed in accordance with NFPA 70 (NEC) (latest
edition) (in Canada, Canadian Electrical Code CSA C22.1)
and local electrical codes.
! WARNING
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. Insulate low--voltage wires for highest voltage contained
within conduit when low--voltage control wires are in
same conduit as high--voltage wires.
5. Do not damage internal components when drilling
through any panel to mount electrical hardware, conduit,
etc.
! CAUTION
High--Voltage Connections
When routing power leads into unit, use only copper wire between
disconnect and unit. The high voltage leads should be in a conduit
until they enter the duct panel; conduit termination at the duct
panel must be watertight.
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 switch box may be mounted on the
unit over the high--voltage inlet hole when the standard power and
low--voltage entry points are used (See Fig. 3 and 4 for acceptable
location).
See unit wiring label (Fig. 15, 16 and 17) and Fig. 11 for reference
when 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 (if equipped).
4. Connect field L1 to black wire on connection 11 of the
compressor contactor.
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 (if equipped).
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.
Make sure the power supply to the unit is switched OFF and
install lockout tag. before making any wiring changes. 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
ELECTRICAL SHOCK FIRE/EXPLOSION HAZARD
Failure to follow this warning could result in personal
injury or death and property damage.
Before making any wiring changes, make sure the gas
supply is switched off first. Then switch off the power
supply to the unit and install lockout tag.
! WARNING
Control Voltage Connections
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
Run the low--voltage leads from the thermostat, through the inlet
hole, and into unit low--voltage splice box.
Locate six (seven for 3--phase) 18--gage wires leaving control box.
These low--voltage connection leads can be identified by the colors
red, green, yellow, brown, blue, and white (See Fig. 11). A gray
wire is standard on 3--phase units for connection to an economizer.
Ensure the leads are long enough to be routed into the low--voltage
splice box (located below right side of control box). Route leads
through hole in bottom of control box and make low--voltage
48E
S
--
A