Central Vac low voltage wiring question

Hi everyone..hope I'm in the correct sub-forum.

My mother's central vac died while in use yesterday.

I'm thinking it may be a bad/loose wire in the low voltage trigger/switch run.

I just checked the 2 low voltage wires that plug into the vac power unit and there is NO continuity. I'm no electrician but I think there should be continuity...or am I out to lunch?

Also, if I disconnect these 2 wires at the power unit and jumper the 2 connections should the motor fire up? Just to rule out motor failure?

Any of your thoughts are welcome!

TIA

 

If you disconnect the wires at the power unit and short the terminals the vac should start.
If you check for continuity on the wires while still disconnected you will only see continuity when one of the vac doors is open, or when the on/off switch on the hose is on (depending on which type of system you have). You will only measure continuity under the condition where unit would normally run.

If it doesn't run when you short the terminals, make sure unit is getting power. Then check for a reset button on the power unit; they usually have a built in circuit breaker. If resetting the breaker fixes it, unplug the unit, remove the bottom housing and reach way up inside and make sure the coarse filter screen isn't all plugged up. Hope this helps.

 

Thought about my question and realized there should be continuity IF the hose was plugged into one of the receptacles and there was.

Still curious if it's safe to jump the low voltage inputs on the power unit to test it.

hmm

 

You can jump the terminals with the wires on or off.

If it's not the push button circuit breaker there are a few other parts that can cause the problem. There is a small transformer and a contactor that is the control circuit.

With a make and model I might be able to post a wiring diagram.