Category Archives for Electric Motors

Resistance-Start Induction-Run Motor

The rotating magnetic field of the resistance-start induction-run motor is produced by the out-of-phase currents in the run and start windings. Since the run winding appears more inductive and less resistive than the start winding, the current flow in the … Continue reading

05. June 2019 by admin
Categories: Electric Motors | Leave a comment

Identifying Motor Capacitor Terminals

Most run capacitors and some starting capacitors are of the oil-filled type. This is especially true for high current motors such as those used to operate compressors. Many manufacturers of oil-filled capacitors will identify one terminal with an arrow, a … Continue reading

18. May 2011 by admin
Categories: Electric Motors | Tags: | Leave a comment

Permanent Split Capacitor Motor

The permanent-split capacitor motor has greatly increased in popularity for use in the air conditioning field over the past years. This type of split-phase motor does not disconnect the start windings from the circuit when it is running. This eliminates … Continue reading

24. April 2011 by admin
Categories: Electric Motors | Leave a comment

Motor Power Consumption

It should be noted that the motor does not use less energy when connected to 240 volts than it does when connected to 120 volts. Power is measured in watts, and the watts will be the same regardless of the … Continue reading

24. April 2011 by admin
Categories: Electric Motors | Leave a comment

Dual Voltage Motor

Single-phase motors can also be constructed to operate on two separate voltages. These motors are designed to be connected to 120 or 240 volts. A common connection for this type of motor contains two run windings and one start winding, … Continue reading

24. April 2011 by admin
Categories: Electric Motors | 1 comment

Testing The Stator Winding

The stator winding of a single-phase motor is generally tested with an ohmmeter. The ohmmeter test can be used to determine if a winding is open or grounded. Many single-phase motors have one lead of the run and start windings … Continue reading

24. April 2011 by admin
Categories: Electric Motors | Leave a comment

Capacitor-Start Induction-Run Motors

Capacitor-start induction-run motors are very similar to resistance-start induction-run motors. The design of the stator winding is basically the same. The main difference is that a capacitor is connected in series with the start winding, as shown in Figure 11–11. … Continue reading

24. April 2011 by admin
Categories: Electric Motors | Leave a comment

The Effects of Voltage Variations on AC Motors

Motors will run at the voltage variations already mentioned. This does not imply such operation will comply with industry standards of capacity, temperature rise, or normally anticipated service life. Figure 7-34 shows general effects. Such effects are not guaranteed for … Continue reading

07. January 2011 by admin
Categories: Electric Motors | Tags: , | Leave a comment

Potential-Type Relay

This relay is generally used with large commercial and air-conditioning compressors (see Fig. 7-31). Motors may be capacitor-start, capacitor-run types up to 5 hp. Relay contacts are normally closed. The relay coil is wired across the start winding. It senses … Continue reading

07. January 2011 by admin
Categories: Electric Motors | Tags: | Leave a comment

Current-Type Relay

The current-type relay is most often used with small refrigeration compressors up to 1 hp. Where power is applied to the compressor motor, the relay solenoid coil attracts the relay armature upward. This causes bridging contact and stationary contact to … Continue reading

07. January 2011 by admin
Categories: Electric Motors | Tags: | Leave a comment

← Older posts