Bryant LEGACY 580J*20M Series, Installation Instructions Manual

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50
LEGEND FOR TABLES 24-25
LEGEND
NOTES:
1. In compliance with NEC requirements for multimotor 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. 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:
Example: Supply voltage is 230-3-60
AB = 224 v
BC = 231 v
AC = 226 v
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.
This amount of phase imbalance is satisfactory as it is below the maxi-
mum allowable 2%.
BRKR — Circuit Breaker
C.O. — Convenience Outlet
DISC — Disconnect
FLA — Full Load Amps
LRA — Locked Rotor Amps
MCA — Minimum Circuit Amps
P.E. — Power Exhaust
PWRD C.O. — Powered Convenience Outlet
UNPWR C.O. — Unpowered Convenience Outlet
% Voltage
Imbalance
= 100x
max voltage deviation from average voltage
average voltage
Average Voltage =
(224 + 231 + 226)
=
681
= 227
3 3
% Voltage Imbalance = 100x
4
= 1.76%
227
IMPORTANT: If the supply voltage phase imbalance is more than
2%, contact your local electric utility company immediately.
A B C
MOTOR