Syncronous Motor

[peetey]

I have a few questions about sychronous motors. I am a Journeyman Meterman by trade and we have some old mechanical meters on our system that use synchronous motors (rotors) as a timing mechanism for demand metering. I know that these are more frequency dependent. I am wondering if I have a 240v rated synch motor how low or high can the voltage be before it has an effect on the speed or performance of the sych motor?

peetey

 

[davidbeach]

No effect on speed if it turns at all. Voltage tolerance would be part of the meter specification and probably varies by meter style and manufacturer.

 

[7anoter4]

I think you mean "selsyn" which is an abbreviation for “self synchronous”.
There are two types: torque transmitter-receiver and control transformer. Also there is a type with slip ring and other without contact.
See:

http://www.allaboutcircuits.com/vol_2/chpt_13/11.html

 

[waross]

Hi New Post7anoter4;
In a metering environment with TOU metering these are probably a marriage of an old (synchronous motor) electric clock and a washing machine control.
The timer in a TOU meter must keep the time of day and either mechanically or electrically switch between kWHr registers at definite times of the day.

Bill
--------------------
"Why not the best?"
Jimmy Carter

 

[7anoter4]

Hi waross
It is very interesting, indeed. I remember a kwhmeter provided with 2 kWh registers-one for night hours , for a cheaper kWh, and one for the day hours. But synchronized TOU system it is something new for me.
Many thanks
Best Regards

 

[waross]

Hi 7anoter4;
This would be a synchronous motor clock that keeps time normaly and switches from the day time register to the night time register at the proper time.

Bill
--------------------
"Why not the best?"
Jimmy Carter