Electronics Gurus--Off Topic Question

[npalen]

Wondering if the solid state relay shown would be appropriate to power a clothes washer? It would be used in conjunction with the drain monitor to kill power to the washer if the drain overflows.

DiversiTech WS-1 Wet Switch Flood Detector: Household Alarms And Detectors: Amazon.com: Industrial & Scientific

My concern is the "leakage" of the relay as opposed to a mechanical relay and how that might affect the electronics in the washer control. Also thinking that a heat sink might be required?

Any suggestions appreciated including alternative devices. I just happen to have the Crydom on hand.
Thanks in advance.

 

[vvanders]

When it comes to line voltage stuff I'm a big fan of physically isolated components. Relays, transformers and the like. Solid state stuff does behave differently, even the optically isolated variety.

 

[mrmikey]

It's rated 25A so I assume it would be fine but I'm no mechanical engineer. You'd have to make sure you broke the hot and not the neutral for safety of anyone working on the washer that might think it's dead is the only issue I can think of.
Vvanders has a valid point also about being isolated........Mike

 

[Ken]

This relay could be mounted on wall high enough to not get wet. then a transformer out put of 24volts to sensor should the water fail to drain. Have used this type to alarm when the chillers froze and then defrosted causing water to flood the floor.

Your washing machine using 120 volts would be no different than a power fail when running.


ken

 

[Diggin It]

Enclosed relays with contacts rated for 110V and sufficient amperage are cheap and commonly available. Match the coil voltage to whatever your control device puts out. Myself, I would rig up a box, basically an extension cord type thing with the relay inside. Cord to plug into the wall outlet, relay inside the box and a new outlet mounted to it. Plug the washer into that new outlet. That way, you don't have to alter the washer in any way.

Those relays aren't very big, so you may be able to use a standard double gang surface box (one of the grey outdoor types).

 

[mikester]

Wondering if the solid state relay shown would be appropriate to power a clothes washer? It would be used in conjunction with the drain monitor to kill power to the washer if the drain overflows.

DiversiTech WS-1 Wet Switch Flood Detector: Household Alarms And Detectors: Amazon.com: Industrial & Scientific

My concern is the "leakage" of the relay as opposed to a mechanical relay and how that might affect the electronics in the washer control. Also thinking that a heat sink might be required?

Any suggestions appreciated including alternative devices. I just happen to have the Crydom on hand.
Thanks in advance.

Here’s food for thought...
Fail of the Week: Solid State Relay Fails Spectacularly | Hackaday

I personally wouldn’t be buying these on eBay...

Most industrial guys I know favour mechanical relays with high voltage coils to ensure positive engagement. I.e. don?t choose to switch 120VAC loads with 5VDC coils

 

[ChiefBodie]

Why don't you skip the electronics and have the washer empty into a holding tank upstream from the drain? When you prepare the next load, if the holding tank is not drained you don't start again until it is.

 

[WVBill]

Why not just use something purpose-built?

Amazon.com: WaterWatcher Leak Detector: Home Improvement

 

[skipperbrown]

I've never heard of a drain for a washer backing up. The washer has a lint/foreign matter trap in front of the pump. Has this been a problem in the past?

 

[npalen]

Thanks for all the ideas and suggestions. They are all appreciated and I will respond to a few of them:

Ken--My concern is the few milliamps of leakage current that passes thru even when the relay is "off". The washer would see this current but may not be a problem.

Diggin It--I was kind of thinking of the small box idea and I agree on the availability of mechanical relays.

Mikester--Your "Fail of the week" is enough to scare me.

WVBill--Good find. I would need a long extension cord as the washer is on ground floor while the drain is in the basement floor.

ChiefBodie--I thought about the holding tank near the drain in the basement but if the drain plugs there would still be water on the concrete. With that in mind, I did build a holding tank of sorts. It consists of a 6' length of 6" PVC drain pipe to serve as the vertical part of the drain connection between floors. It will hold about 8 gallons of drain water and has holes at the top end so that the water can't back up to the first floor and flood. At the bottom is a 5/8" orifice which sounds too small but handles the washer pump's output well.

The water would overflow the top of the 6" riser if the orifice ever plugged which would be fine as the water would drain down the outside of the riser and down into the floor drain.
If the floor drain ever plugs, however, I need a way to shut off the washer pump and hence the need for the sensor operated relay in the power to the washer.

The floor drain is normally capable of easily handling the flow 99%+ of the time but there's that one time.