Magnetic Motor Control

Heater coils are rated to protect 40½°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:

• (a) For 50½°C, 55½°C, 75½°C rise motors and enclosed motors having a service factor of 1.0, select one size smaller coil.
• (b) Ambient temperature of controller lower than motor by 26½°C (47½°F) use one size smaller coil.
• (c) Ambient temperature of controller higher than motor by 26½°C (47½°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.

Manual Motor Control

Heater coils are rated to protect standard 40°C rise motors, and open and drip proof motors having a service factor of 1.15 at approximately 125% of rated motor current, and where controller and motor are at same ambient.

Heater coil ranges provide for variations in all enclosure sizes and designs, including internal heating. Selection tables are not compromises or averaged values thereby providing maximum motor output and life.
For other conditions:

• (a) 50½°C or 55½°C rise motor and enclosed motor having a service factor of 1.0 with protection at 115% of rated current, use one size smaller coil.
• (b) Ambient temperature of controller lower than motor by: 8.5-16.7½°C (16-30½°F) use one size larger coil. 16.8-27.8½°C(31-50½°F) use two sizes smaller coil.
• (c) Ambient temperature of controller higher than motor by: 8.5-16.7½°C (16-30½°F) use one size larger coil. 16.8-27.8½°C (31-50½°F) use two sizes larger coil.