I N S TA L L AT I O N , O P ER AT I O N S A N D M A I N T EN A N C E M A N UA L
37
Heaters for ther-mag circuit breaker controllers
For continuous-rated motors with a service factor
of 1.15 to 1.25, select the appropriate heaters for
the motor full-load current. For continuous-rated
motors with a service factor of 1.0, multiply the
motor full-load current by 0.9 and use this value
to select heaters.
Overload relay tripping current in 40°C ambient
is the minimum value of full-load current multiplied
by 1.25.
Provide short-circuit protection in accordance with
the National Electrical Code.
Size 0 and 1 (Standard and Ambient Comp.)
Size 2 (Standard and Ambient Comp.)
Overload heaters
Overload relays with automatic reset may
automatically start a motor connected to a two-
wire control circuit. When automatic restarting
is not desired, use a three-wire control circuit.
Circuit breaker tripping may be an indication that
a fault current has been interrupted. To provide
continued protection against fire or shock hazard,
examine all current-carrying parts and other
components of the motor controller and replace
any damaged components. If heater burnout
occurs, the complete overload relay must
be replaced.
Motor Full-
Load Amps
3-Ph, 3 Heater
Heater
Number
CR123
Motor Full-
Load Amps
3-Ph, 3
Heater
Heater
Number
CR123
.41-.45
C054A
4.96-549
C592A
.46-.49
C060A
5.50-5.91
C630A
.50-.53
C066A
5.92-6.47
C695A
.54-.59
C071A
6.48-7.20
C778A
.60-.65
C078A
7.21-8.22
C867A
.66-.76
C087A
8.23-8.72
C955A
.77-.84
C097A
8.73-9.67
C104B
.85-.93
C109A
9.68-10.4
C113B
.94-1.04
C118A
10.5-11.0
C125B
1.05-1.15
C131A
11.1-12.4
C137B
1.16-1.27
C148A
12.5-13.2
C151B
1.28-1.39
C163A
13.3-15.4
C163B
1.40-1.55
C184A
15.5-17.1
C180B
1.56-1.73
C196A
17.2-18.0
C198B
1.74-1.89
C220A
Size 1
1.90-2.05
C239A
2.06-2.28
C268A
17.2-18.1
C198B
2.29-2.47
C301A
18.2-20.0
C214B
2.48-2.79
C326A
20.1-21.5
C228B
2.80-3.31
C356A
21.6-22.5
C250B
3.32-3.70
C379A
22.6-23.9
C273B
3.71-4.06
C419A
24.0-26.3
C303B
4.07-4.47
C466A
26.4-27.0
C330B
4.48-4.95
C526A
Motor Full-
Load Amps
3-Ph, 3 Heater
Heater
Number
CR123
Motor Full-
Load Amps
3-Ph, 3 Heater
Heater
Number
CR123
5.48-5.85
C630A
16.8-17.9
C180B
5.85-6.47
C695A
18.0-18.7
C198B
6.48-7.35
C778A
18.8-20.4
C214B
7.36-8.06
C867A
20.5-22.7
C228B
8.07-9.03
C955A
22.8-24.7
C250B
9.04-9.61
C104B
24.8-26.3
C273B
9.62-10.5
C113B
26.4-29.5
C303B
10.6-11.6
C125B
29.6-32.5
C330B
11.7-12.5
C137B
32.6-36.7
C366B
12.6-13.6
C151B
36.8-41.9
C400B
13.7-16.7
C163B
42.0-43.2
C440B
43.3-45.0
C460B