Hello guys, I'm new to the forum. And could use a bit of advice. I've recently been work on a small hobby room / pub in my garage. My brother in law gave me a old Dayton 2E669B electric heater, never been used. After talking to a friend that does HVAC he told me I should be able to just use a switch instead of a thermostat so I used a 120v light switch. The heater worked as it should except one wire that comes from one of the 120 legs gets hot. Hotter than I feel comfortable with. I've been scratching my head for days. So my question is would a line volt thermostat do anything different than the switch? It did come with a wiring diagram so I'm pretty sure everything is where it should be. Thanks for taking the time to read this.
Dayton electric heater issues.
- Thread starter budman80
- Start date
ambenz
Well-known member
Could you show us, in a wiring diagram, how you have the whole unit wired?
Sounds like the wire you talking about in drawing amperage.
What is the gauge of the wire in question?
Sounds like the wire you talking about in drawing amperage.
What is the gauge of the wire in question?
I have a service box in my garage and I wired the heater into it. That wire is getting hot because it isn't big enough. My heater has a built in thermostat, it's a Dayton I got from grainger, actually it's on right now. It isn't very big but once I get it warm I'll turn it down or it'll get hot out there. My garage is insulated and dry walled but the garage door isn't.
I am surpised that it does not have a contactor in the circuit? Do you have an amp probe (anything to measure the current) if so, put it on the wire in question and see what its drawing, looks to me that its going to the element.
ambenz
Well-known member
From what I can see...that's almost 24.5 amps going through the wire and switch!!!!
Stop...now!
Might get a larger gauge wire...10 awg at least!
Those switches are usually only rated for 20 amps.
The specific thermostat for that heater had a duel throw relay in it rated for at least 30 amps with 2 separate contacts.
I bet the switch is getting warm too!
The wire is very warm for that reason!
Best to get the "special" thermostat rated for that unit...it was made to handle the amprage.
Stop...now!
Might get a larger gauge wire...10 awg at least!
Those switches are usually only rated for 20 amps.
The specific thermostat for that heater had a duel throw relay in it rated for at least 30 amps with 2 separate contacts.
I bet the switch is getting warm too!
The wire is very warm for that reason!
Best to get the "special" thermostat rated for that unit...it was made to handle the amprage.
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nehog
Well-known member
From what I can see...that's almost 24.5 amps going through the wire and switch!!!!
Wrong!
That heater is rated at 208 volts, not 240 volts. At 240 volts the current goes up to almost 29 amps, power from 5 KW to about 6.9 KW. I'm not sure, since it has no 240 volt rating on that plate, whether it can be safely be used on 240 volts.
LS6 Tommy
Well-known member
PLEASE TURN IT OFF NOW AND CALL AN ELECTRICIAN!!
No dispect intended, but that model is a 208/240 VAC unit. You can't safely substitute a 120 VAC 15A light switch for the proper line voltage controls.
Tommy
No dispect intended, but that model is a 208/240 VAC unit. You can't safely substitute a 120 VAC 15A light switch for the proper line voltage controls.
Tommy
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Well, it can be wired with a 1 or 2 pole T-Stat, its wired for a 1 pole and he has a 15 amp switch in place of the T-Stat, if the 15 amp switch is to small, then the wiring is also. Have you had this heater or just picked it up? just curious what size breaker do you have this on? just wondering if all original parts are/were there or if someone else has worked on this? maybe?
Cant really see the element wiring that well?
Cant really see the element wiring that well?
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nehog
Well-known member
No, it is a 208 volt only unit. Again, it is not safe to operate at 240 volts. Of course the internal wiring is heating up--it's overloaded.
dave67fd
Well-known member
Although the nameplate is listed for 208 (Typical commercial single phase from a 3 phase system) the schematic lists 208/240/277 single phase supply.
It is a heater and will run fine on 240 volts. The listed current will be lower at 240 than at 208.
OP, Remove the light switch and install with a rated LINE voltage thermostat with the properly sized wire. Better yet have an electrician wire it for you before you burn your place down.
Syberia
Well-known member
The heating element has a set resistance, unless there are multiple elements and multiple wiring configurations for the unit. If you increase the voltage over a set amount of resistance, the current also increases proportionally in a resistive load. 240 volts will pull more amps and output more watts of heat than 208.
Another vote for more amps and higher voltage, 28-29 amps is what I calc as well and about 6600W.
V=IR so I=V/R. Raise voltage and keep resistance the same means more amps and more watts because P=I^2 x R. Google any resistive heater rated for 208/240/277, all increase wattage with voltage. You are running near double the rated switch capacity so there is your problem. Most line voltage thermostats are rated for around 22-23 amps so you need a heavy duty one rated for 30A.
V=IR so I=V/R. Raise voltage and keep resistance the same means more amps and more watts because P=I^2 x R. Google any resistive heater rated for 208/240/277, all increase wattage with voltage. You are running near double the rated switch capacity so there is your problem. Most line voltage thermostats are rated for around 22-23 amps so you need a heavy duty one rated for 30A.
Charles (in GA)
Well-known member
The wiring diagram is generic for that model heater. Since the data plate specifies only 208 volts, especially since the motor is only 208 volt, it won't work properly on 240v. Fan will run slow, and possibly overheat eventually.
Charles
Charles
nehog
Well-known member
Not sure where you got your degree in electrical engineering, but you got cheated. Learn the basic electrical rule: Ohm's Law. Now tell me how your statements above meet Ohm's law?
The name plate describes the unit, not the schematic. The schematic is generic.
I'm outta here, there is so much bad information here that it is a waste of time. It is the wrong heater for the application, and I've said all I need to say.
LS6 Tommy
Well-known member
I totally agree that the unit is only rated for 208. Since no nameplate or diagram was posted at the point I replied, I only went by the WW Grainger model number listed by the OP. Their website called it 208/240...
Tommy
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LS6 Tommy
Well-known member
Actually, you are the one who is wrong. If resistance stays the same and voltage increases, current increases. The motor current drops at the higher voltage because there are two different windings for the two voltages...
Tommy
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kogerat
Member
The whole thing looks pretty scary, but the OP could probably get away with it if he used a switch rated for 250VAC @ 30 AMPS and #10 wire, that is if he didn't electrocute himself first!
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