Bryant 542J Series Installation, Start-Up And Service Instructions Manual page 9

LEGEND
EQUIP GND — Equipment Ground
kcmil — Thousand Circular Mils
NEC — National Electrical Code
TB — Terminal Block
NOTE: The maximum wire size for TB1 is 350 kcmil for all unit voltages.
Fig. 13 — Field Power Wiring Connections
Fig. 14 — Field Control Thermostat Wiring
4. Voltage to compressor terminals during operation must
be within voltage range indicated on unit nameplate (also
see Table 2). Voltages between phases must be balanced
within 2% and the current within 10%. Use the formula
shown in Table 2, Note 3, to determine the percent volt-
age imbalance. Operation on improper line voltage or
excessive phase imbalance constitutes abuse and may
cause damage to electrical components. Such operation
would invalidate any applicable warranty.
5. Insulate low-voltage wires for highest voltage con-
tained within conduit when low-voltage control wires are
run in same conduit as high-voltage wires.
6. Do not damage internal components when drilling through
any panel to mount electrical hardware, conduit, etc.
High-Voltage Field Power Wiring Connections (Fig. 13)
The unit must have a separate electrical service with a field-
supplied, waterproof, fused disconnect switch mounted at, or
within sight from, the unit. Refer to the unit rating plate for
maximum fuse/circuit breaker size and minimum circuit amps
(ampacity) for wire sizing. Be sure disconnect switch does not
obstruct unit rating plate.
The field-supplied disconnect switchbox may be mounted on
the unit over the high-voltage inlet hole in the control corner
panel.
Proceed as follows to complete the high-voltage connections
to the unit:
1. Connect ground lead to chassis ground connection when
using separate ground wire.
2. Unit has a terminal block for field power connections.
Install conduit connectors in side panel power supply
knockout openings indicated in Fig. 2 and 3. Route power
lines through connector to unit control box.
Special Procedures for 208-V Operation
DANGER: Make sure that the power supply to the
unit is switched off before making any wiring changes.
Electrical shock can cause personal injury or death.
For operation on 208 v:
1. Remove the cap from the splice containing the orange
(230 v) transformer primary lead and 2 black wires. See
unit wiring diagram.
2. Remove cap from the red (208 v) transformer primary
lead.
3. Use cap from red lead to splice red lead and 2 black wires
together.
4. Cap the orange lead.
5. Check to be sure no copper wire is left exposed at both
caps.
Control Voltage Connections (Fig. 14)
Install a factory-approved room thermostat. Refer to unit Trade
Prices or contact your local representative for more informa-
tion. Locate the thermostat on an inside wall in the space to
be conditioned where it will not be subjected to either a cool-
ing or heating source or direct exposure to sunlight. Mount
the thermostat 4 to 5 ft above the floor.
NOTE: For wire runs up to 50 ft, use no. 18 AWG (American
Wire Gage) insulated wire (35 C minimum). For 51 to 75 ft,
use no. 16 AWG insulated wire (35 C minimum). For 76 to
155 ft, use no. 14 AWG insulated wire (35 C minimum). All
wire larger than no. 18 AWG cannot be connected directly to
the thermostat and will require a junction box and splice at
the thermostat.
Heat Anticipator Setting
The room thermostat heat anticipator must be properly ad-
justed to ensure proper heating performance. Set the heat
anticipator to settings in Table 3.
Failure to make a proper heat anticipator adjustment may
result in improper operation, discomfort to the occupants of
the conditioned space, and inefficient energy utilization; how-
ever, the required setting may be changed slightly to provide
a greater degree of comfort for a particular installation.
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