Carrier WeatherMaster 50HCQ04-12 Service And Maintenance Instructions page 58

Legend and Notes
LEGEND
BRKR — Circuit breaker
C.O. — Convenience outlet
DISC — Disconnect
EFF — Efficiency
FLA — Full load amps
LRA — Locked rotor amps
MCA — Minimum circuit amps
P.E. — Power exhaust
Pwrd fr/unit — Powered from unit
PWRD C.O. — Powered convenience outlet
UNPWR C.O. — Unpowered convenience outlet
NOTES:
1. In compliance with NEC requirements for multi-motor and combi-
nation load equipment (refer to NEC Articles 430 and 440), the
overcurrent protective device for the unit shall be fuse or HACR
breaker. Canadian units may be fuse or circuit breaker.
2. For 208/230 v units, where one value is shown it is the same for
either 208 or 230 volts.
3. 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 per-
centage of voltage imbalance.
APPENDIX D — ELECTRICAL INFORMATION (cont)
Applicable for Electrical Data Tables AJ-AU
% Voltage Imbalance = 100 x
Example: Supply voltage is 230-3-60
A B
MOTOR
Average Voltage =
Determine maximum deviation from average voltage.
(AB) 227-224 = 3 v
(BC) 231-227 = 4 v
(AC) 227-226 = 1 v
Maximum deviation is 4 v.
Determine percent of voltage imbalance.
% Voltage Imbalance = 100x
This amount of phase imbalance is satisfactory as it is below the maxi-
mum allowable 2%.
IMPORTANT: If the supply voltage phase imbalance is more
than 2%, contact your local electric utility company
immediately.
NOTE: Check all factory and field electrical connections for
tightness.
58
max voltage deviation from average voltage
average voltage
AB = 224 v
C
BC = 231 v
AC = 226 v
(224 + 231 + 226) 681
=
3 3
4
= 1.78%
227
= 227