Carrier 50ZHA024-060 Installation & Service Instructions Manual Download

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Table 3—Minimum Airflow for Safe Electric Heater

Operation (CFM)

SIZE

024

030

036

042

048

060

Cfm

600

750

900

1050

1200

1500

UNIT DAMAGE HAZARD
Failure to follow this caution may result in unit component
damage. Operation of unit on improper line voltage consti-
tutes abuse and may cause unit damage that could affect
warranty.

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 unit;
conduit termination at the unit must be watertight. Run the
high-voltage leads through the hole on the control box side of the
unit (see Fig. 7 for location). When the leads are inside the unit,
run leads to the control box (Fig. 8). For single-phase units,
connect leads to the black and yellow wires (see Fig. 9).

CONNECTING GROUND LEAD TO UNIT GROUND

Refer to Fig. 8 and 9. Connect the ground lead to the chassis using
the unit ground in the control box.

ROUTING CONTROL POWER WIRES

Form a drip-loop with the thermostat leads before routing them
into the unit. Route the thermostat leads through grommeted hole
provided in unit into unit control box (See Fig. 7). Connect
thermostat leads and unit power leads as shown in Fig. 9, 10A &
10B.

Route thermostat wires through grommet providing a drip-loop at
the panel. Connect low-voltage leads to the thermostat as shown in
Fig. 10A & 10B.

The unit transformer supplies 24-v power for complete system
including accessory electrical heater. Transformer is factory wired
for 230-v operation.

ACCESSORY ELECTRIC HEAT WIRING

Refer to accessory electric heat installation instructions for infor-
mation on installing accessory electric heat. Accessory electric
heat wiring is shown in Fig. 11A, 11B, & 11C.

PRE-START-UP

FIRE, EXPLOSION, ELECTRICAL SHOCK HAZARD
Failure to observe the following warnings could result in
serious injury, death and/or property damage:
1. Follow recognized safety practices and wear protective

goggles when checking or servicing refrigerant system.

2. Do not operate compressor or provide any electric power to

unit unless compressor terminal cover is in place and
secured.

3. Do not remove compressor terminal cover until all electri-

cal sources are disconnected and lockout tag is installed.

4. Relieve all pressure from both high- and low-pressure sides

of the system before touching or disturbing anything inside
terminal box if refrigerant leak is suspected around com-
pressor terminals. Use accepted methods to recover refrig-
erant.

5. Never attempt to repair soldered connection while refrig-

erant system is under pressure.

6. Do not use torch to remove any component. System

contains oil and refrigerant under pressure. To remove a
component, wear protective goggles and proceed as fol-
lows:
a. Shut off electrical power to unit and install lockout tag.
b. Relieve all refrigerant from system using both high- and

low-pressure ports. Use accepted methods to recover
refrigerant.

c. Cut component connecting tubing with tubing cutter and

remove component from unit.

d. Carefully unsweat remaining tubing stubs when neces-

sary. Oil can ignite when exposed to torch flame.

Use the Start-Up Checklist supplied at the end of this book and
proceed as follows to inspect and prepare the unit for initial
start-up:

1. Remove all access panels.

2. Read and follow instructions on all DANGER, WARNING,

CAUTION, and INFORMATION labels attached to, or
shipped with unit.

Make the following inspections:

a. Inspect for shipping and handling damages such as broken

lines, loose parts, disconnected wires, etc.