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The above values of full-load currents are typical for

motors running at speeds usual for belted motors with

normal torque characteristics. Motors built for low

speeds (1200 RPM or less) or high torques may require

more running current, and multi-speed motors will have

full-load current varying with speed, in which case the

nameplate current ratings apply.

The voltages listed are rated motor voltages. The

currents listed are permitted for system voltage ranges

of 230 to 240 and 440 to 480 volts.

The amperages given here are approximate values only and represent averages compiled from the tables of leading

motor manufacturers. Overload relay heaters should not be selected on the basis of these tables only. Heaters must

be selected in accordance with the actual motor current as shown on the nameplate. It is also important that

ambient temperatures of the area in which the motor control is located be taken into consideration when making

heater selection. Ambient compensated overload relays are available for abnormal temperature conditions.

NOTE:

On most roof exhausters the motor synchronous speed is 1800 RPM.

HP

115V

208V

230V

1/6

1/4

1/3

1/2

3/4

1

3.8

4.2

6.2

8.2

10.0

13.7

2.0

2.1

3.1

4.1

5.0

6.8

1.9

2.1

3.1

4.1

5.0

6.8

HP

208V

230V

460V

1/2

3/4

1

1-1/2

2

3

5

2.4

1.7

3.6

4.8

6.0

9.3

14.6

2.4

1.7

3.6

4.8

6.0

8.4

13.2

1.2

0.9

1.8

2.4

3.0

4.2

6.6

SINGLE PHASE

THREE PHASE

The table data shown above is from the NEC 1996

edition, table 430-150.

The above values of full-load currents are for motors

running at usual speeds for direct connected motors

with normal torque characteristics. Motors built for

especially low speeds or high torques may have higher

full-load currents and multi-speed motors will have

full-load current varying with speed, in which case the

nameplate current ratings apply.

The voltages listed are rated motor voltages. The

currents listed are permitted for system voltage ranges

of 110 to 120 and 230 to 240 volts.

8

ADP

– Serving the HVAC Industry Since 1952

Nominal Ampere Ratings