AIM Manual

Motor Application » Three-Phase Motors (Page 29)

Overload Protection

Overload Protection of Three-Phase Submersible Motors

Class 10 Protection Required

The characteristics of submersible motors are different than standard motors and special overload protection is required.

If the motor is locked, the overload protection must trip within 10 seconds to protect the motor windings. Subtrol/ SubMonitor, a Franklin-approved adjustable overload relay, or a Franklin-approved fixed heater must be used.

Fixed heater overloads must be the ambient-compensated quick-trip type to maintain protection at high and low air temperatures.

All heaters and amp settings shown are based on total line amps. When determining amperage settings or making heater selections for a six-lead motor with a Wye-Delta starter, divide motor amps by 1.732.

Pages 29, 30 and 31 list the correct selection and settings for some manufacturers. Approval for other manufacturers’ types not listed may be requested by calling Franklin’s Technical Service Hotline at 800-348-2420.

Refer to notes on page 30.

Table 29 - 60 Hz 4" Motors
HPKWVOLTSNEMA
STARTER
SIZE
HEATERS FOR
OVERLOAD
RELAYS
ADJUSTABLE
RELAYS
(NOTE 3)
FURNAS
(NOTE 1)
G.E.
(NOTE 2)
SETMAX
1/20.372000K31L380A3.23.4
2300K28L343A2.72.9
3800K22L211A1.71.8
4600-L174A1.41.5
5750--1.21.3
3/40.552000K34L510A4.14.4
2300K32L420A3.53.8
3800K27L282A2.32.5
4600K23L211A1.81.9
5750K21L193A1.51.6
10.752000K37L618A55.4
2300K36L561A4.44.7
3800K28L310A2.62.8
4600K26L282A2.22.4
5750K23L211A1.81.9
1.51.12000K42L750A6.36.8
2300K39L680A5.55.9
3800K32L420A3.33.6
4600K29L343A2.83
5750K26L282A2.22.4
21.52000K50L111B8.69.3
2300K49L910A7.58.1
3800K36L561A4.64.9
4600K33L463A3.84.1
5750K29L380A33.2
32.22000K55L147B11.612.5
2300K52L122B10.110.9
3800K41L750A6.16.6
4600K37L618A5.15.5
5750K34L510A4.14.4
53.72001K62L241B19.120.5
2301K61L199B16.617.8
3800K52L122B1010.8
4600K49L100B8.38.9
5750K42L825A6.67.1
7.55.52001K68L322B28.430.5
2301K67L293B24.626.4
3801K58L181B14.916
4601K55L147B12.313.2
5751K52L122B9.910.6
107.53801K62L241B19.521
4601K60L199B16.117.3
5751K56L165B12.913.6
15113802 (1)K70L322B2931.2
4602 (1)K67L265B2425.8
5752 (1)K62L220B19.320.7