Open neutral error wiring STC1000

[TennBrewer]

I got my STC1000 from Amazon the other day and proceeded to wire it up, following the advice and techniques from the many fine people of HBT. I then tested the connections after programming the controller for 30 degrees C and 1 minute compressor delay. The STC1000 responded by enabling the heating mode. I used an outlet tester, basically a 3-pronged plug with 3 lights (one red, two amber) to indicate status. The heating outlet showed normal but when I plugged the tester into the cooling outlet, it indicated an "open neutral". I held the temperature probe in my hand until the temperature went above 30 at which time the controller switched into cooling mode. After the one minute compressor delay the cooling outlet was activated. The plug tester indicated that it was normal, but now the heating outlet test showed "open neutral". I double checked the wiring with several sources, then triple-checked it. It all looked right and all resources were in concert. I used my multimeter to check all connections and even tested the outlet alone by wiring it directly to the power cord. Nothing.

Then it hit me.

In all the sources I found for wiring the STC1000 controller, all of them instructed you to remove the metal tab which between the two connectors in the outlet. I don't recall them ever saying WHICH tab to break away, some outlets have one side brass the other gray colored. The outlet I was using had both sides the same color. The tab you break DOES make a difference! Most outlets these days have one side that is larger than the other side, the shorter size opening is the hot side, the longer sized opening is the neutral side. You must remove the tab from the HOT side only, if you remove the wrong tab, you will get an "open neutral" condition which could be dangerous.

I'm just posting this message as an FYI to anyone who may run into this problem, I have been tearing my hair out all afternoon trying to fix this problem. Hope now nobody else has to now.

 

[day_trippr]

Thanks for the post.

fwiw, I can't recall any dual-stage controller thread over the last four years where it wasn't made clear (eventually, if not from the jump) to break the hot-side bridge on a duplex outlet...

Cheers!

 

[TennBrewer]

It may be true that which tab to break away may have been stated, but I may have overlooked that part of it. The point being that this minute little detail is very important and may not have been emphasized enough in the text or videos. I have seen a couple of YouTube videos on this and this detail was not mentioned or if it was, it was not stressed enough. It may be painfully obvious to many who have already been through this, but for some who are venturing for the first time into unfamiliar territory, these little details need to be explained up front. The lesson learned here is to read and understand all materials before you begin. Pay attention to details and take it one small step at a time. I am guilty of not following my own advice, hoping others will be more diligent.