IVS vac won't shutdown

[chaz]

Hi all....

Arrived at wash on Friday one motor of one vac would not shutdown. Adding payment would start timer and second motor and operated as a normal cycle, but the one motor remained on after timer was at 00:00

Replaced relay and relay base, all seemed fine until today (Sunday), 1 motor running. For now I have shut the vac down as it's too cold to investigate further.

Thoughts...

 

[MEP001]

Failing motor fusing relay contacts?

 

[Greg Pack]

I'm assuming an old IVS combo with IDX timer setup? IIRC they do use a IDX relay with a SCR in them, which can fuse when too high a load is applied to them (Mep001s failing motor hypothesis) Once those modules failed I swapped out to a mercury relay with no problems afterwards. IDX didn't like the idea because of some voltage spike yada, yada, yada. However, mine has worked for years that way.

On the IVS basic units with just a timer, I installed an inline fuse on each vac motor. A bad motor will just blow the fuse and not take the timer with it.

 

[chaz]

It's a basic IVS vac with Dixmor led7 timer. Warmer today so I will spend done time on this. Might just swap both motors. I do like the fuse idea, what amp fuse are you using? I assume on the line going to the relay?
Tks

 

[cantbreak80]

The Dixmor energizes the 24vac coil of the relay. 120vac (Line) is supplied to the Common terminals of the relay. When the relay coil is energized, the relay’s normally open contacts close, supplying 120vac to the motors (Load).

Add fuses between the relay and the motors (Load) to save the relay.
Adding a fuse to the Line will not save the relay.

For best protection, use 10A slow-blow fuses…one for each motor.

 

[2Biz]

Is there one set or two sets of contacts in the relay? If there's only one contact and both motors are wired to same contact, then how is one motor continuing to run after time out? Has to be two sets of contacts with each motor wired to different contacts in the relay? I would think if those relays are that troublesome, you'd put in a 24v mercury relay and wire both vac motors to the single relay. That's how I have mine wired.. Never a problem...24v mercury relays are rated for 30A...You could still fuse each motor for protection...

 

[cantbreak80]

I was assuming an older (Mike Doyle's IVS) vacuum. The several hundred 3 motor units that I sold were equipped with 3-pole relays (brand name escapes me) rather than a mercury relay. I can't speak to the Ginsan/IVS versions.

 

[sparkey]

I second the Mercury relay. I used to get vacuum motor relays welded shut all the time until I switched to Mercury relays. Haven't had a problem since.

 

[MEP001]

Third - I get the 35A relays from Kleen-Rite. It's just a couple bucks more than the 30A.