Bryant 551B, 551A manual Legend And Notes For Electrical Data Tables Pages, 558F036-150

LEGEND AND NOTES FOR ELECTRICAL DATA TABLES PAGES 65-69

558F036-150

LEGEND

FLA — Full Load Amps

HACR — Heating, Air Conditioning and Refrigeration

IFM — Indoor (Evaporator) Fan Motor

LRA — Locked Rotor Amps

MCA — Minimum Circuit Amps

MOCP— Maximum Overcurrent Protection

NEC — National Electrical Code

OFM — Outdoor (Condenser) Fan Motor

RLA — Rated Load Amps

*Heater capacity (kW) is based on heater voltage of 208 v, 240 v, 480 v, and 600 v. Heaters are rated at 240 v, 480 v, or 600 v. If power distribution voltage to unit varies from rated heater voltage, heater kW will vary accordingly. To determine heater capacity at actual unit volt- age, multiply 240 v, 480 v, or 600 v capacity by multipliers found in table on page 64.

†Used to determine minimum disconnect size per NEC. **Heaters are field installed only.

††Fuse or HACR circuit breaker.

Fusing in single point box provides the required branch circuit protection.

NOTES:

1.In compliance with NEC requirements for multimotor and combina- tion load equipment (refer to NEC Articles 430 and 440), the overcur- rent protective device for the unit shall be fuse or HACR breaker. The Canadian units may be fuse or circuit breaker.

2.Unbalanced 3-Phase Supply Voltage

Never operate a motor where a phase imbalance in supply voltage is greater than 2%. Use the following formula to determine the percent of voltage imbalance.

% 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 percent of voltage imbalance.

7

% Voltage Imbalance = 100 x 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.

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