OVERLOAD RELAY HEATER SELECTION TABLES
OVERLOAD RELAY HEATER SELECTION TABLES
Data Based on Furnas Tables 393 and 398 for Three-Phase Motors
Class 16 DP Model
Motor SF Amps
16A, 16B, 16C
16D, 16E
1.91
2.08
2.26
2.44
2.7
2.98
3.22
3.61
3.93
4.23
4.67
5.02
5.46
6.25
6.74
7.25
8.05
8.55
9.8
10.3
12.0
12.5
13.6
14.7
15.5
16.9
17.9
19.1
22.0
23.6
25.2
27.0
30.0
34.0
37.1
41.0
46.0
49.2
56.0
–
–
–
–
Starter Size / Max. Amps
16A / 25
16B / 30
16C / 40
16D / 50
16E / 60
K
Heater
No.
–
K21
–
K22
–
K23
–
K24
–
K26
–
K27
–
K28
–
K29
–
K31
–
K32
–
K33
–
K34
–
K36
–
K37
–
K39
–
K41
–
K42
–
K43
–
K49
–
K50
–
K52
–
K53
–
K54
–
K55
–
K56
–
K57
–
K58
–
K60
22.5
K61
24.1
K62
25.7
K63
28.0
K64
31.1
K67
34.6
K69
37.8
K70
41.5
K72
50.0
K73
54.0
K74
57.0
K75
60.0
K76
66.0
K77
73.0
K78
80.0
K79
16F / 75
16G / 90
16H / 120
16I / 150
Class 16 DP Model
Motor SF Amps
16F, 16G ①
16H, 16I
50.2
53.2
58.0
62.2
65.5
72.0
80.0
–
85.0
93.0
97.5
104
–
119
–
–
–
–
–
–
Selection tables are used with the motor service
factor amps if known, otherwise use motor full
load amps multiplied by a factor of 1.15. Select
the heater closest to but higher than the SFA
(motor trip amps).
NOTE: These charts are only for Class 16 Definite
Purpose, Ambient Compensated Starters (identi-
fied by a green reset button) using Quick Trip
(class 10) K heaters for Submersible Motors. Other
Classes or Brands of Starters require different
selection tables, consult the manufacturer for
information specific to that brand/class.
Selection example: Motor service factor
amps = 9. If using a 16AC starter, select a
K49 heater since it is the next higher heater
amp rating number above 9 amps.
① Our current 16F and 16G starters are equipped
with ESP100 adjustable overloads and do not
require heaters. Use this chart only for older
starters requiring K heaters.
K
Heater
No.
50.1
K72
53.1
K73
58.0
K74
62.1
K75
65.5
K76
72.0
K77
80.0
K78
–
K79
85.0
K83
93.0
K85
97.5
K86
104
K87
114
K88
126
K89
136
K90
150
K92
162
K93
180
K94
190
K96
200
K97
21