Step 6 - Make Electrical Connections - Bryant 559F Installation, Start-Up And Service Instructions Manual

Fig. 10 — Condensate Drain Piping Details
VI. STEP 5 — MAKE ELECTRICAL CONNECTIONS
A. Field Power Supply
Unit is factory wired for voltage shown on nameplate.
When installing units, provide a disconnect, per NEC (Na-
tional Electrical Code) requirements, of adequate size
(Table 2).
All field wiring must comply with NEC and local
requirements.
Route power lines through control box access panel or unit
basepan (Fig. 4 and 5) to connections as shown on unit wir-
ing diagram and Fig. 11.
Operating voltage to compressor must be within voltage range
indicated on unit nameplate. On 3-phase units, voltages be-
tween phases must be balanced within 2% and the current
must be balanced within 10%.
CAUTION: The correct power phasing is critical in
the operation of the scroll compressors. An incorrect phas-
ing will cause the compressor to rotate in the wrong di-
rection. This may lead to premature compressor failure.
Use the following formula to determine the percentage of volt-
age imbalance.
Percentage of Voltage Imbalance
max voltage deviation from average voltage
= 100 x
average voltage
EXAMPLE: Supply voltage is 460-3-60.
AB = 452 v
BC = 464 v
AC = 455 v
Average Voltage =
Determine maximum deviation from average voltage:
(AB) 457 − 452 = 5 v
(BC) 464 − 457 = 7 v
(AC) 457 − 455 = 2 v
Maximum deviation is 7 v.
Determine the percentage of voltage imbalance:
Percentage of Voltage Imbalance = 100 x
452 + 464 + 455
3
1371
=
3
= 457
7
457
= 1.53%
This amount of phase imbalance is satisfactory as it is below
the maximum allowable 2%.
IMPORTANT: If the supply voltage phase imbalance is
more than 2%, contact your local electric utility company
immediately.
Unit failure as a result of operation on improper line voltage
or excessive phase imbalance constitutes abuse and may cause
damage to electrical components.
B. Field Control Wiring
Install a Bryant-approved accessory thermostat assembly ac-
cording to the installation instructions included with the ac-
cessory. Locate thermostat assembly on a solid wall in the
conditioned space to sense average temperature.
Route thermostat cable or equivalent single leads of
no. 18 AWG (American Wire Gage) colored wire from subbase
terminals through conduit in unit to low-voltage connections
as shown on unit label wiring diagram and in Fig. 12.
NOTE: For wire runs up to 50 ft, use no. 18 AWG insulated
wire (35 C minimum). For 50 to 75 ft, use no. 16 AWG insu-
lated wire (35 C minimum). For over 75 ft, use no. 14 AWG
insulated wire (35 C minimum). All wire larger than
no. 18 AWG cannot be directly connected to the thermostat
and will require a junction box and splice at the thermostat.
Set heat anticipator settings as indicated in Table 3. Settings
may be changed slightly to provide a greater degree of com-
fort for a particular installation.
Refer to accessory
required.
TB1 MAXIMUM WIRE SIZE
UNIT
559F
All
EQUIP — Equipment
GND — Ground
kcmil — Thousand Circular
Mils
Fig. 11 — Field Power Wiring Connections
UNIT LOW-VOLTAGE CONNECTIONS
Fig. 12 — Field Control Thermostat Wiring
—8—
remote control instructions
VOLTAGE
208/230 460
350 kcmil 2/0
LEGEND
NEC — National Electrical
Code
TB — Terminal Block
as