Ranco 2 stage controler, don't try this with it.

I'm now using my 24x24 barn as a fermenting room. It's well insulated so I figure I should be able to keep it at temp easy enough.
So I put and electric space heater out there and after some playing around with the built in temp control I got the barn to hold steady at 60*. Well I wanted better control so I bought a Ranco 2 stage thermostat. It's rated for 120v at 16 amps. My heater is 12.5 amps. I figured this would be great.
After setting up the Ranco I had some problems with it. I had the stage one for cooling and stage two for heat. Heater was plugged into stage 2. Heat was on but once it hit temp and shut off it would not come back on. I found this out two days later and the barn was at 45*. I used some propane heat to help get it back up and I tried it again. Next day it was cold again.
I then switched it to stage one and set it to heat. That fixed the problem and all was good.
I set up another heater and a fan on the other side of the barn. This heater is on low and runs all the time as does the fan. The main heater was being triggered by the Ranco.
This past Saturday I was out there and it was all good. But working hard to hold the 60* I wanted.
It's Tuesday night now and I step out to see how it's doing and when I walked in I got hit in the face with the smell of electrical burn. You know that smell right?
The fan and low heater are running, check, the main heater is not. I look at the Ranco and it's on and showing that it was 58*. Ok the heater should be on but it's not. I unplug the heater and plug it into the wall. It's fires right up. Ha, it's the Ranco.
When I removed the Ranco from the wall I see the problem.


I damn near burned down my barn. That would have been a huge loss. I got so lucky that it burned it's self out without igniting the wall.

On a side note. The heater is now just plunged into the wall and it's not working hard at all to keep the temp. I don't think these Ranco controls are built to run space heaters.

 

Not cool. Just curious, have you checked the amp draw on that heater with an ammeter to verify it's only pulling 12.5 amps?

 

No I was just going by the tag on the heater.
But one thing that is true is the heater runs a lot better not going thru the Ranco.

 

I would definitely check the current draw on the heater.

Not saying it wasn't the Ranco, but I'd want to be sure if it were my property that could burn down.

 

Well I don't have a meter to check it but I just went back out there and it's sitting at 62* so I backed the heaters down so they will stay right there. Nothing is hot, the cords and outlets are all cold.
Looking at the Ranco I see that the stage 1 relay is what burned down. My guess is that it can't handle that kind of draw for that long. This last week was our first cold week with highs in the low 30's and with it getting so cold in there the heaters were working hard to get it back up to temp.
I wont buy another Ranco that's for sure.
Thinking as the winter progresses and gets colder I may end up building a 6x8 cold room in the barn so that I don't have to heat as large of a space.

 

Had a heat lamp do that to my first Love controller. It shorted out and drew too much power through the controller... bad things ensued. If I had to guess it is drawing more than it should. Always possible the controller was defective too though.

 

The heater seems to be running as it should. If I had been home last night I would have found this yesterday. The wife informed me that when she got home yesterday all the clocks in the house were blinking. We had a power outage it seems. My bet is that when the power went out and came back on that instant surge from the heater overloaded the relay.

 

According to this page ETC Supply (which also states it is rated to 16 amps) the resistive loads relay ratings for the 120V NO contact are only 9.8A, much less than your 12.5A heater is drawing. I think that was you issue. I have no idea why they are stating that it can handle 16 amps!
If I woere you I would be returning it to whoever you bought it from, damanding a refund because they mislead you with the 16 amp claim and also demand that they change their their product description to acurately discribe the controllers limitations/ratings.

Ha, I found out the 16A claim - only the single stage controller is rated for 16 amps! THE 2 STAGE IS NOT RATED FOR 16 AMPS- THE 2 STAGE IS ONLY RATED FOR 9.6 AMPS!

 

Wow - look at all the bold fonts!

Just to clarify, ETC doesn't "claim" the 2-stage controller is rated for 16A...

Cheers!

 

OK, your right they don't claim and do state halfway down the page "The Ranco ETC-211000 is identical to the Ranco ETC-111000 except that this unit is 2 stage, and has 2 relays to control both heating and cooling at the same time. (The output relay NC and NO ratings are also different)" (so it is not really at all identical then?)

But for most people reading it they would take the first statement on the 2 stage controollers page that the Ranco ETC controllers are suitable to switch loads up to 16 amps as meaning the Ranco 2 stage ETC contrller can be used with 16 amp loads. It seems that at least the OP did.

Yep, might have over done it with the bold all caps but wanted to make sure no one missed that point

 

Yes I sure did. Everything I have read on these always stated that they were the same but now I'm seeing that they are not.
This does explain why the heater seemed to work harder and not put out as much heat once I hooked into the Ranco.