Bryant 548D User Manual

Page 7

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V. STEP 5 — MAKE ELECTRICAL CONNECTIONS

A. Field Power Supply

All units except 208/230-v units are factory-wired for the
voltage shown on the unit nameplate. If the 208/230-v unit is
to be connected to a 208-v power supply, the transformer
must be rewired by disconnecting the black wire from the
230-v terminal on the transformer and connecting it to the
200-v terminal from the transformer.

Refer to unit label diagram for additional information. Pig-
tails are provided for field wire connections. Use factory-
supplied splices or UL (Underwriters’ Laboratories)
approved copper/aluminum connector.

When installing units, provide a disconnect per the NEC.

All field wiring must comply with the NEC and local re-
quirements. In Canada, electrical connections must be made
in accordance with CSA (Canadian Standards Association)
C22.1 Canadian Electrical Code Part One.

Install field wiring as follows:

1. Install conduit through side panel openings. For units

without electric heat, install conduit between discon-
nect and control box.

2. Install power lines to terminal connections as shown

in Fig. 7.

3. For units with electric heat, refer to Accessory Instal-

lation Instructions.

4. If thru-the-bottom control connections are used, refer

to the accessory installation instructions for informa-
tion on control wiring. Refer to Fig. 6 for drilling holes
in basepan.

During operation, voltage to compressor terminals must be
within range indicated on unit nameplate (see Tables 2A and
2B). On 3-phase units, voltages between phases must be bal-
anced within 2%, and the current within 10%. Use the for-
mula shown in Tables 2A and 2B, Note 2 on page 10 to
determine the percentage of voltage imbalance. Operation on
improper line voltage or excessive phase imbalance consti-
tutes abuse and may cause damage to electrical compo-
nents. Such operation would invalidate any applicable
warranty.

WARNING: Unit cabinet must have an uninter-

rupted, unbroken electrical ground to minimize the
possibility of personal injury if an electrical fault
should occur. This ground may consist of electrical wire
connected to unit ground lug in control compartment,
or conduit approved for electrical ground when
installed in accordance with NEC (National Electrical
Code) ANSI (American National Standards Institute) /
NFPA (National Fire Protection Association) 70 latest
year and local electrical codes. Failure to follow this
warning could result in the installer being liable for
personal injury of others.

LEGEND

— Contactor

COMP — Compressor
IFC

— Indoor Fan Contactor

NEC

— National Electrical Code

— Terminal Block

Field Wiring
Factory Wiring
Splice Connection
(Factory-Supplied)

208/230-3-60

460-3-60

575-3-60

Fig. 7 — Power Wiring Connections