Technical data
33-148
For more information contact Cutler-Hammer at: www.ch.cutler-hammer.com/catalog CAT.201.01.T.E
January 2001
NEMA Contactors & Starters
33
Thermal and Fast Trip Overload Relays
A200 Line
Vol. 2, Ref. No. [0164]
Heater Selection
General Information on Heater Coil Selection
For maximum motor protection and compliance with Article
430-32 of the National Electrical Code, select heater coils
from the tables in this section on the basis of motor name-
plate full load current.
When the full load current is unknown, selection may be
made on the basis of average full load currents as shown on
Pages 33-164 – 33-165 of the Cutler-Hammer product guide.
Caution — The average ratings could be high or low for a
specific motor and therefore selection on this basis always
involves risk. For fully reliable motor protection, select
heater coils on the basis of full load current rating as shown
on the motor nameplate.
Heater coils are rated to protect 40°C rise motors, and
open and drip-proof motors having a service factor of 1.15
where the motor and the controller are at the same ambient
temperature.
For other conditions:
1. For 50°C, 55°C, 75°C rise motors and enclosed motors
having a service factor of 1.0, select one size smaller
coil.
2. Ambient temperature of controller lower than motor by
26°C (47°F), use one size smaller coil.
3. Ambient temperature of controller higher than motor by
26°C (47°F), use one size larger coil.
Ultimate tripping current of heater coils is approximately
1.25 times the minimum current rating listed in the tables.
Table 33-254. Heater Selection — Type A and B Overload Relays,
Sizes 3 and 4
Table 33-255. Heater Selection — Type A and B Overload Relays,
Sizes 5 and 6
Note: Size 7 and Larger — Advise Full Load Current.
Size
Starter
Ambient
Compensated
Enclosed Starters
Non-
compensating
Enclosed
Starters
Heater
Catalog
Number
Price
U.S. $
All Applications
Full Load Current of Motor Amps
12.8 – 14.1
14.2 – 15.5
15.6 – 17.1
17.2 – 18.9
19.0 – 20.8
11.9 – 13.0
13.1 – 14.3
14.4 – 15.9
16.0 – 17.4
17.5 – 19.1
FH68
FH69
FH70
FH71
FH72
10.70
10.70
10.70
10.70
10.70
20.9 – 22.9
23.0 – 25.2
25.3 – 27.8
27.9 – 30.6
30.7 – 33.5
19.2 – 21.1
21.2 – 23.2
23.3 – 25.6
25.7 – 28.1
28.2 – 30.8
FH73
FH74
FH75
FH76
FH77
10.70
10.70
10.70
10.70
10.70
33.6 – 37.5
37.6 – 41.5
41.6 – 56.3
46.4 – 50
51 – 55
30.9 – 34.5
34.6 – 38.2
38.3 – 42.6
42.7 – 46
47 – 51
FH78
FH79
FH80
FH81
FH82
10.70
10.70
10.70
10.70
10.70
56 – 61
62 – 66
67 – 73
74 – 78
52 – 56
57 – 61
62 – 67
68 – 72
FH83
FH84
FH85
FH86
10.70
10.70
10.70
10.70
79 – 84
85 – 92
73 – 77
78 – 84
FH87
FH88
10.70
10.70
93 – 101 85 – 91 FH89 10.70
102 – 110
111 – 122
123 – 129
130 – 133
—
92 – 99
100 – 110
111 – 122
123 – 128
129 – 133
FH90
FH91
FH92
FH93
FH94
10.70
10.70
10.70
10.70
10.70
For Size 4 Starters
For Size 3 Starters
Compensated Overload Relay Heater
Catalog
Number
Price
U.S. $
Open Starter Enclosed Starter
Full Load Current of Motor (Amps)
Size 5 (with 300/5 Current Transformers)
—
118 – 129
130 – 141
142 – 155
156 – 170
171 – 187
188 – 205
206 – 224
225 – 244
245 – 263
264 – 292
293 – 300
—
118 – 129
130 – 141
142 – 155
156 – 170
171 – 187
188 – 205
206 – 224
225 – 244
245 – 263
264 – 292
—
FH23
FH24
FH25
FH26
FH27
FH28
FH29
FH30
FH31
FH32
FH33
FH34
10.70
10.70
10.70
10.70
10.70
10.70
10.70
10.70
10.70
10.70
10.70
10.70
Size 6 (with 600/5 Current Transformers)
—
236 – 259
260 – 283
284 – 310
311 – 340
341 – 374
375 – 411
412 – 448
449 – 489
490 – 527
528 – 585
586 – 600
—
236 – 259
260 – 283
284 – 310
311 – 340
341 – 374
375 – 411
412 – 448
449 – 489
490 – 527
528 – 540
—
FH23
FH24
FH25
FH26
FH27
FH28
FH29
FH30
FH31
FH32
FH33
FH34
10.70
10.70
10.70
10.70
10.70
10.70
10.70
10.70
10.70
10.70
10.70
10.70
Discount Symbol . . . . . . . . . . . . . . . . . . . . . . . 1CD1C
Tab3305.fm Page 148 Monday, October 23, 2000 10:19 PM