Bryant 580F - Manual (Page 14)

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LEGEND AND NOTES FOR TABLES 2A AND 2B
LEGEND
*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.
208/230-3-60: Compressor no. 2 RLA is 14.1 amps and LRA is
105 amps.
460-3-60: Compressor no. 2 RLA is 7.1 amps and LRA is 55 amps.
575-3-60: Compressor no. 2 RLA is 6.4 amps and LRA is 40 amps.
POWER EXHAUST ELECTRICAL DATA
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 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 (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
POWER EXHAUST
PART NO.
MCA
(230 v)
MCA
(460 v)
MCA
(575 v)
MOCP
(for separate
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
= 100 x
max voltage deviation from average voltage
average voltage
Average Voltage =
452 + 464 + 455
3
=
1371
3
7
457