Fried STC-1000

[ds0oc1]

Just tried to wire up my first STC-1000 and as soon as I plugged it in she ****ing fried.



This is the wiring diagram I used:



Not really sure where I could have went wrong - the diagram is pretty simple. I double checked everything 10 times before plugging it in and after it fried. I noticed that the wires were burnt where they would have plugged into the relay at 6 and 8.

Where did I go horribly wrong?

 

[Wynne-R]

The diagram is correct. Somehow the receptacle shorted, smoking the relay. I’ve never seen a receptacle short, more likely it’s a cable or plug.

Was anything plugged in? Was it in a metal box?

You need to get an ohm-meter. Check across the terminals on the receptacle (wall outlet in the box). Unhook stuff one at a time until the short goes away.

 

[Jim_Holmes]

did you remember to cut the tab? not sure if it that would cause that or not

 

[AkTom]

Did you break off the tab between the two plugs? I had one my after several batches. Thankfully I bought two of them, so I had a spare.
Tom

 

[day_trippr]

Leaving the duplex outlet tabs intact would not cause this failure - unless something was plugged in - or two somethings plugged in - that grossly exceeded the STC relay circuit load capacity.

With the straps intact whatever was plugged in to either outlet would be powered when either STC relay was active.

To me it looks like there were direct shorts from AC to ground or neutral across both relays...

Cheers!

 

[raouliii]

Just tried to wire up my first STC-1000 and as soon as I plugged it in she ****ing fried...

This is the wiring diagram I used:
...
Not really sure where I could have went wrong - the diagram is pretty simple. I double checked everything 10 times before plugging it in and after it fried. I noticed that the wires were burnt where they would have plugged into the relay at 6 and 8.

Where did I go horribly wrong?

I would hazard a guess that hot and neutral were crossed at the receptacle or a short was plugged into it. If you have a photo of the wiring prior to plugging it in, I'm sure HBT can identify where the wiring diverged from the diagram.

 

[ds0oc1]

I would hazard a guess that hot and neutral were crossed at the receptacle or a short was plugged into it. If you have a photo of the wiring prior to plugging it in, I'm sure HBT can identify where the wiring diverged from the diagram.

Thanks for the replies everyone - I'll get a photo up later.

When you say I had the hot/neutral crossed... you mean that I might had the two cables crossed on the bottom side of the receptacle?

 

[Kwitty]

Is it possible you wired it upside down? That would have flipped all the connections. Almost did it myself the first one I wired!

 

[raouliii]

Thanks for the replies everyone - I'll get a photo up later.

When you say I had the hot/neutral crossed... you mean that I might had the two cables crossed on the bottom side of the receptacle?

That kind of damage was the result of too much current passing through the unit; probably at the relay(s). It was likely the result of hot and neutral meeting at the relay when it switched on. This could have been the result of wiring the receptacle incorrectly, like attaching hot to one brass screw and neutral to the other brass screw; badaboom, big badaboom.

Is it possible you wired it upside down? That would have flipped all the connections. Almost did it myself the first one I wired!

That's another possibility.