ECN Forum Forums Code Related Discussion Canadian Electrical Code Topics 2 Phase Motor

Just a question about motors. What is a two phase motor? I have installed single and three phase ones but I have always been curious what 2 phase motors are and where they are used.



[This message has been edited by RobbieD (edited 02-03-2007).]

This link may help.
http://www.orientalmotor.com/MotionControl101/2phase-v-5phase-intro.htm

2 Phase Induction Motors were once the Industry Standard items - back in the early 1900's.

The 2 Phase Polyphase AC System was used in many areas, and was derived either solely from 2 Phase 4 Wire Distribution, or from 3 Phase 3 Wire Distribution - which was the more common method.

Variations of the 2 Phase Systems + Motors sprouted into some currently used types.

Small Dry-Type Polyphase Transformers are connected as Open Delta "Tee", which was a very common connection technique for 2 Phase 4 Wire Systems derived from 3 Phase 3 Wire Distribution.
These currently used Open Delta Tee Systems range up to 15 KVA, with Voltage Ratings of:

* 480 VAC x 208Y/120V 3 Phase 4 Wire,

* 480 VAC x 240/120V 3 Phase 4 Wire Delta,

* 480 VAC x 240V 3 Phase 3 Wire Delta,

* 600 VAC x 208Y/120V 3 Phase 4 Wire,

* 600 VAC x 240/120V 3 Phase 4 Wire Delta,

* 600 VAC x 240V 3 Phase 3 Wire Delta.

There are also 2 Phase 3 and 4 Wire Servo Motors in use today, for AI (Robotics) and related applications.

Scott35

Thanks for the answers. I understand what they are more now. I guess they are motors that use two different phases so they don't rely on a capacitor for the phase shift like single phase motors. I just never saw one before and was curious to what they were all about.
Thanks again.

Forgot to mention:

Check the Technical Reference Section, for Schematics and some details regarding 2 Phase Motors + Transformer Connections.

Refer to the Menu For Technical Reference Area https://www.electrical-contractor.net/ubb/Forum15/HTML/000064.html
For links to the 2 Phase related pages.

Scott35

Thanks Man!