Bryant 542J Heat Pump User Manual


 
64
ELECTRICAL DATA (cont)
LEGEND AND NOTES FOR ELECTRICAL TABLES
LEGEND
*Heaters are field installed only.
Used to determine minimum disconnect size per NEC.
**Heater capacity (kW) is based on heater voltage of 208 v, 240 v,
480 v, and 575 v. If power distribution voltage to unit varies from rated
heater voltage, heater kW will vary accordingly.
††Fuse or HACR circuit breaker.
***Optional disconnect switch is unavailable.
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.
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
Example: Supply voltage is 460-3-60.
AB = 452 v
BC = 464 v
AC = 455 v
= 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.
% Voltage Imbalance = 100 x
= 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.
FLA
Full Load Amps
HACR
Heating, Air Conditioning and Refrigeration
IFM
Indoor Fan Motor
LRA
Locked Rotor Amps
MCA
Minimum Circuit Amps
MOCP
Maximum Overcurrent Protection
NEC
National Electrical Code
OFM
Outdoor Fan Motor
RLA
Rated Load Amps
= 100 x
max voltage deviation from average voltage
average voltage
Average Voltage =
452 + 464 + 455
3
=
1371
3
7
457
50TFQ004-012
548F036-120