[bspratt22]

installed a in duct dryer fan

about a year ago and was never able to get the current sensing switch working;
got a 2nd switch and it also did not work. Basically you run either "hot" leg of the 220 circuit through the sensing switch as pictured and this should close the leg (when dryer turned on) at the top enabling the 110 to turn on the fan. I have an electrician friend who verified the switch never would close during our tests. So I ended up bypassing the whole mess with a simple smart switch controlled by Alexa. "alexa turn on dryer fan; alexa turn off drying fan" works fine but kind of frustrating you must remember to do this. Does anyone have experience or suggestions on getting this current switch to work? Alternate ideas? I may just hard wire the fan to a wall switch in back of the dryer that would turn on both at the same time. (yes the dryer is 220 and the fan 110 but I think this can be done) Thanks for any thoughts at all - Bill

 

[surferdude2]

Try looping through the current sensor switch hole with 3 or more turns or wire.

 

[bspratt22]

I will try your suggestion of looping TY!

 

[bspratt22]

THANK YOU VERY MUCH for the suggestion of looping the cable through 3 times! That worked and I almost could not believe it! Now the fan comes on whenever the dryer is turned on as designed. Wow, waited a year for this - TY!!!

 

[bspratt22]

This is a minor thing but after getting things working I tested the outlet receptacle with a tester and it said neutral open. But both the dryer fan and the attic light controlled by the toggle switch at top worked on/off perfectly. After taking more time to put everything back together "perfectly" (only change was adding a ground for the outlet receptacle itself) the toggle switch when turned off stayed on - the attic light that is. No big deal because the attic light has a pull string to turn off. Also now when I put the tester in the receptacle it says "CORRECT". No open neutral - so not overly concerned but have no idea what might cause this.

 

[brric]

A bigger deal is the open splices in an attic.

 

[seharper]

I assume the open box and puke of wires and splices all over your attic is just temporarily lying there for testing. Make sure you install it properly inside junction boxes when you're done.

 

[surferdude2]

I'm glad to hear it's functioning as intended for you.

Get and mount a 6x6x4 metal junction box (with ko's) and some 2-screw cable connectors and enclose that current sensor and all the junctions in it and you'll be all safe and set.

 

[bspratt22]

Sorry, I did not post pictures of finished job! I did install 2 junction boxes for the 2 large splices going to and from the current sensor switch. I did not enclose the switch itself because (in my mind at least) there is no real juice flowing from the output of this same switch just a on or off to the bottom of the receptacle turning the attic fan on/off. I will be glad to enclose it along with the one lead that runs through the switch if this is recommended. Maybe use flex conduit to run from junction box to switch; enclose the switch in a 3rd box and finally flex conduit from switch to 2nd junction box? Just want it to be safe here; but I'm curious as to why the toggle switch on the receptacle would no longer open? Just ran out of time yesterday or would have tested...thanks again!

 

[roughneck]

Post pictures of the finished product.
We like pictures.

 

[bspratt22]

Ok here are pictures - please go easy - I'm a novice here and I'm sure we are not in code here : ) Also included schematic that my friend put down on paper thanks - Bill

 

[bspratt22]

Can someone please tell me if I need to box up the current switch itself? Because to do that means putting the other wires (neutral and 2nd hot) in with the 1st hot wire - looped around current switch - and for some reason I'm thinking that could affect the switch? Or just get a huge box that sort of allows you to separate the current sensing lead from the others?

 

[roughneck]

I would put it in a box.
The other stuff needs all redone ASAP.
Those boxes need to be securely mounted, and cannot have wire running through a knockout without a connector.
That’s both a fire and a short hazard.

 

[RAL238]

Can someone please tell me if I need to box up the current switch itself? Because to do that means putting the other wires (neutral and 2nd hot) in with the 1st hot wire - looped around current switch - and for some reason I'm thinking that could affect the switch? Or just get a huge box that sort of allows you to separate the current sensing lead from the others?

Since there are 120V terminals on the current sensor, you need to enclose it in a box. Also, the red wire running through the sensor is a single conductor, as is (I think) the white wire that runs between the 2 junction boxes. They can't be out in the open like that - they also should all be within an enclosure.

A better way to do this would be to mount everything all in one large junction box, like an 8" x 8" x 6".

 

[Datawise]

Purchase one big box (6 x 6 or 8 x 8) and put everything in it.

Nothing should be exposed.

Cheers
John

 

[bspratt22]

Thanks everyone just purchased the parts tonight to do things right. Not cheap. Thinking about opening an electrical supply house. Holy cow the prices! I do appreciate the honest and helpful feedback - Bill

 

[bspratt22]

Ended up using the 4 inch box for the current sensor and screwing them together with previous boxes and conduit - buttoning it all up together while fastening the center box down. Thanks again to everyone on this thread/forum for your help and insight but special thanks goes to surferdude2!