LEGEND AND NOTES FOR TABLES 2A AND 2B
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
*The values listed in this table do not include power exhaust. See table below for power exhaust requirements.
†Used to determine minimum disconnect per NEC. **Fuse or HACR circuit breaker.
††Fuse only.
***Compressor no. 1 data indicated in table.
POWER EXHAUST ELECTRICAL DATA
POWER EXHAUST | MCA | MCA | MCA | MOCP | |
(for separate | |||||
PART NO. | (230 v) | (460 v) | (575 v) | ||
power source) | |||||
CRPWREXH021A00 | N/A | 0.9 | N/A | 15 | |
CRPWREXH022A00 | 3.3 | N/A | 1.32 | 15 | |
CRPWREXH023A00 | N/A | 1.8 | N/A | 15 | |
CRPWREXH024A00 | 1.6 | N/A | 0.64 | 15 | |
CRPWREXH025A00 | N/A | 0.9 | N/A | 15 | |
CRPWREXH026A00 | 3.3 | N/A | 1.32 | 15 | |
CRPWREXH027A00 | N/A | 1.8 | N/A | 15 | |
CRPWREXH028A00 | 1.7 | N/A | 0.68 | 15 | |
CRPWREXH029A00 | N/A | 1.0 | N/A | 15 | |
CRPWREXH030A00 | 1.6 | N/A | 0.64 | 15 |
N/A — Not available
NOTE: If a single power source is to be used, size wire to include power exhaust MCA and MOCP. Must be in accordance with NEC or local codes.
Check MCA and MOCP when power exhaust is powered through the unit. Determine the new MCA including the power exhaust using the fol- lowing formula:
MCA New = MCA unit only + MCA of Power Exhaust
For example, using a 580FPV090 unit with MCA = 40.1 and MOCP
=45, with CRPWREXH030A00 power exhaust. MCA New = 40.1 amps + 1.6 amps = 41.7 amps
If the new MCA does not exceed the published MOCP, then MOCP would not change. The MOCP in this example is 45 amps and the MCA New is below 45; therefore the MOCP is acceptable. If “MCA New” is larger than the published MOCP, raise the MOCP to the next larger size. For separate power, the MOCP for the power exhaust will be 15 amps per NEC.
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. Canadian units may be fuse or circuit breaker.
2.Unbalanced
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
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.
% Voltage Imbalance = 100 x |
| 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.
