Bryant 559F VI. Ð Make Electrical Connections, Field Power Supply, Field Control Wiring, Gnd

Models: 559F

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Fig. 10 Ð Condensate Drain Piping Details

VI. STEP 5 Ð 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 ®eld 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

= 100 x

max voltage deviation from average voltage

average voltage

 

EXAMPLE: Supply voltage is 460-3-60.

AB = 452 v

BC = 464 v

AC = 455 v

Average Voltage =

452 + 464 + 455

3

 

=

1371

 

3

=

457

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:

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 remote control instructions as required.

TB1 MAXIMUM WIRE SIZE

 

UNIT

 

VOLTAGE

 

559F

 

208/230

 

460

 

All

 

350 kcmil

 

2/0

 

 

 

LEGEND

 

 

EQUIP Ð Equipment

NEC Ð National Electrical

GND

Ð Ground

 

 

Code

kcmil

Ð Thousand Circular TB

Ð Terminal Block

 

Mils

 

 

 

Fig. 11 Ð Field Power Wiring Connections

Percentage of Voltage Imbalance = 100 x

7

457

= 1.53%

UNIT LOW-VOLTAGE CONNECTIONS

Fig. 12 Ð Field Control Thermostat Wiring

Ð8Ð

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Bryant 559F operation manual VI. Ð Make Electrical Connections, Field Power Supply, Field Control Wiring, Unit Voltage, Gnd