Legend And Notes For Electrical Tables - Carrier 50TFQ004 Product Data

Single-package standard efficiency rooftop heat pump units 3 to 10 nominal tons
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LEGEND
FLA
— Full Load Amps
HACR — Heating, Air Conditioning and Refrigeration
— Indoor Fan Motor
IFM
LRA — Locked Rotor Amps
MCA — Minimum Circuit Amps
MOCP— Maximum Overcurrent Protection
NEC — National Electrical Code
OFM — Outdoor Fan Motor
RLA — Rated Load Amps
*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
max voltage deviation from average voltage
= 100 x
average voltage

LEGEND AND NOTES FOR ELECTRICAL TABLES

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 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.
452 + 464 + 455
3
1371
=
3
= 457
7
457
61

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