Dual Voltage Single Phase Motor only runs on 115v.?

[stevecedarkey]

Hello,

I have a dual voltage water pump motor that until recently ran on 230v. It stopped working recently and now will only run on 115v. There is an internal switch in the motor that can be set on 230v. or 115v. I have checked the line voltage going to the pressure switch and each leg reads 115v. The motor is only 1 year old and after disassembling it - it looks new inside, no burnt windings, etc.

Hoping someone can tell me what may have happened to it. I have not yet tested the function of the dual voltage switch but there is nothing that looks bad visually. The connections all appear to be solid. Anyone?

 

[jraef]

Does your motor have one capacitor on it, or two? I suspect it's the kind with two, that's what usually comes with a switch like that. In either voltage, the caps are in the LV aux winding, but for 230V the two are in series, in 115V, one of them is not used at all. So most likely the switch has a bad contact in it and when switched to 230V, you don't get the complete circuit. But in 115V, it only needs the one cap so the other one not being connected by the switch is irrelevant.


"You measure the size of the accomplishment by the obstacles you had to overcome to reach your goals" -- Booker T. Washington

 

[stevecedarkey]

My motor has only one capacitor and I have run preliminary tests and it appears to be good. I will go ahead and do some testing on the switch.

Any other thoughts? Thank you.....

 

[zlatkodo]

stevecedarkey,
An issue is probably related to the switch.

for 230V the two are in series, in 115V, one of them is not used at all

A small correction: Auxiliary winding is always connected to 115 V ( either in LV or HV connection). That is usual connection of NEMA dual voltage, 1ph motors in order to avoid a use of second capacitor.
There is a drawback - a high capacitance is required.

Motor Repair and Winding Design

 

[waross]

I have seen a lot of 115:230 Volt motors. I have never seen one winding abandoned for 115 Volt use.
The run windings are connected in series for 230 Volts and in parallel for 115 Volts.
The start winding is typically a single 115 Volt winding. It is typically connected in parallel with one of the run windings so it always sees 115 Volts. As this winding always sees 115 Volts there is no need to change the start capacitor for 230 volt use.
I agree that your switch may have failed.

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

 

[stevecedarkey]

I will test the switch in the next few days & report back my findings. Thank you for the knowledge and help.....

 

[zlatkodo]

I have never seen one winding abandoned for 115 Volt use.

BTW, there are such a motors.

Winding Data Calculations

 

[waross]

Yes zlatkodo, I have seen a number single voltage 110 Volt or 115 Volt motors. What I have not seen is a motor rated at 115:230 Volts that uses only one 115 Volt run winding on 115 volts. Every dual voltage motor that I have seen, uses both run windings in parallel for 115 Volt application.

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