Installed a Dayton G73....thermostat ideas?

[buening]

Over the weekend I installed a Dayton G73 heater and it will only be used when I'm out in the garage. The problem is the thermostat is out of reach and I'd have to keep a step stool right by the heater and climb on it every time I want to turn the heater on or adjust the thermostat. I thought about installing a switch on the wall to turn the heater on and off, but that doesn't help if I get too warm and need to turn the thermostat down. Do people install a separate thermostat on the wall and keep the thermostat on the heater at full blast? Looking for ideas from people who've installed one of these. For now I'll keep the step ladder below the heater, but my garage is already small enough and the less **** to take up floor space the better!

 

[timgr]

The first thing you can do is place a switch on the wall for on and off. I have two of these heaters in my garage, and each has its own wall switch in addition to the thermostat and the breaker for each 30A circuit. You can buy a switch locally at an electrical supply company or online - here's one source: http://www1.mscdirect.com/CGI/NNSRI...opmainPcircularid=13665Ppagenumber=3344Pmode=

Someone else here has posted a 25A 230V thermostat that can go inline with the power, just like the switch can. Then you can leave the G37 thermostat on high all the time, and control operation from floor level. I don't have a link to these, but you can find them if you search.

(edit) Here you go: http://www.garagejournal.com/forum/showthread.php?t=12969&showall=1

 

[buening]

Thanks! I noticed that the switch is a single pole and that you only switched one of the legs of the 240V. I'm no electrician, but on a 30A double pole breaker is one leg of the 240V 15A? If so, I could get away with a 15A switch...no?

Is a switch required by code even if there is a thermostat installed on the wall (assuming the thermostat has an OFF setting)?

 

[timgr]

No, you can't use a 15A switch. The panel operates on 230V center tapped, but the heater does not. There is no center tap (neutral) going to the heater, so the circuit is truly 30A at 230V, and you are switching the rated 20.9A load at 230V.

JMO - you should understand a little more about how the panel wiring works (and maybe electricity?) before you take on installing something like this.

Can't tell you about whether the thermostat qualifies as a switch under code - I would assume it does. You can look up the exact code wording at the NEMA site
http://www.nfpa.org/aboutthecodes/AboutTheCodes.asp?DocNum=70

 

[TRDon]

Can't tell you about whether the thermostat qualifies as a switch under code - I would assume it does. You can look up the exact code wording at the NEMA site
http://www.nfpa.org/aboutthecodes/AboutTheCodes.asp?DocNum=70

I believe that It could be used as a disconnect pending that it:

-Is within sight of the heater and no more than 50 feet away
-The thermostat has the ability to disconnect all hot sources from the unit.
-The is a difinitive OFF settin got the stat. Turning it down does not qualify although it shuts it off.

That second one could be sticky because I dont think that line level 230V stats switch both hots, I belive they only switch one. I am not positive there but check your stat and see.

 

[timgr]

I believe that It could be used as a disconnect pending that it:

-Is within sight of the heater and no more than 50 feet away
-The thermostat has the ability to disconnect all hot sources from the unit.
-The is a difinitive OFF settin got the stat. Turning it down does not qualify although it shuts it off.

That second one could be sticky because I dont think that line level 230V stats switch both hots, I belive they only switch one. I am not positive there but check your stat and see.

Huh. TRDon is saying that the code requires a disconnect for the heater, not merely an on-off switch. I'm not sure what the code says, since I can't get to the online document, but your circuit breaker panel will serve as a disconnect if it is within line of sight of the heater and less than 50' away.

You can get the line-level thermostat linked above in either a single pole or double pole configuration. The double pole 'stat qualifies as a disconnect by the definition above. However, you only need the single pole 'stat or a single pole switch if you just want to control the heater and not disconnect it.

To Buening, sorry if I was brusque regarding the 15A switch question. Here's some background.

The power comes in from the pole transformer at 230VAC. There is a center tap to the pole transformer (neutral) that divides the incoming power in the middle. Neutral is referenced to ground potential at the panel. Thus you have a "top" half of the panel at 115VAC and a "bottom" half at 115VAC. When you have a double breaker for 230VAC, you are jumping over the neutral to take voltage from the two hot conductors (top and bottom) at the full 230VAC. The heater does not need 115VAC, so no neutral connection is needed.

(picture linked from: http://www.allaboutcircuits.com/vol_2/chpt_10/1.html )

Now, when you put the double breaker in, it has two circuit breakers ganged together. Each of these breakers is in series with the 230VAC load, so each sees the full current drawn by the load; this is two 30A CBs ganged together, one for the top and one for the bottom. You only need one CB to break the circuit and protect the device in case of overload, but for safety each side of the circuit needs to be protected against a short to ground. For example, if at the heater, you accidentally grounded one of the conductors and only the other conductor were protected, that CB would not be tripped. The double breaker is required to protect both conductors against accidental grounding.

hth!

 

[buening]

Nah, it's all good Tim! I'll admit electrical is not one of my strengths. The circuits class back in college proved that! The actual amperage of each leg from a double pole breaker was something I didn't look into much to learn about, more or less thinking out loud (incorrectly). I don't mess with 240V very often.

I had planned on getting a double pole thermostat that has an OFF at its lowest setting, similar to this: http://www.lowes.com/lowes/lkn?action=productDetail&productId=78056-49285-MD26R&lpage=none I need to find the amperage rating of that thermostat though, it doesn't say on the Lowes website.


I will test the OFF function with a voltmeter at the heater once a thermostat is installed, to make sure each leg is disconnected.

 

[timgr]

22A. Should be fine. Google "Fahrenheat MD26R."

 

[TRDon]

Huh. TRDon is saying that the code requires a disconnect for the heater, not merely an on-off switch. I'm not sure what the code says, since I can't get to the online document, but your circuit breaker panel will serve as a disconnect if it is within line of sight of the heater and less than 50' away.

Correct. You could use a switch, but it would have to be a 2 pole switch. The breaker could work if it is within sight of it. I was just answering the direct question of if the stat could be used as the disconnect, but the ways you mentioned would work as well.

 

[Torque1st]

2-pole 30A switches are available at any GOOD hardware store as well as online. Grainger supply had them the last time I looked and so did Strasser hardware. Grainger supply has better specs for their stuff available online. Both places have line level thermostats.

Electrical/electronics was one of my strengths in school and after.