Pigtail, forced air heater

I am in need of installing a recently purchased Fahrenheat (FUH 54) forced air garage heater. It is a 17000 BTU, 240volt, 5000 watt, 20.9 amp heater with a max fuse capacity of 30. The installation instructions call for a 10 gauge hard wired.

I have installed a window air condition unit through the wall of my garage which is fed by 240 volt, 10 gauge wire to a single outlet.

My question is, in as much as it is a single outlet and only one appliance at a time can be active, is there any reason I could not use a pigtail from the heater to the same outlet, alternating which one is plugged in on a seasonal basis?

I'm assuming the pigtail would need to be 10 gauge to meet mfg. specs.

The heater will be suspended from the ceiling as provided by the mfg. brackets and will be within 3-4 feet of the outlet.

Would a pigtail of this nature be available in local hardware stores (Nashville) or would I need to go to an electrical supply store?

Thanks for any assistance you may offer.

joeford said:

I have installed a window air condition unit through the wall of my garage which is fed by 240 volt, 10 gauge wire to a single outlet ...
... is there any reason I could not use a pigtail from the heater to the same outlet, alternating which one is plugged in on a seasonal basis?

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If that is a 30-amp outlet and you use a 30-amp cord for the heater, I cannot see any problem other than possibly the length of the cord. The 30-amp cords I have used for stoves and dryers or whatever were not very long. So, you might end up having to buy a piece of SJ cord or whatever is best and attaching the plug that fits your existing receptacle if everything matches up correctly. You will also need a connector to fasten the cord where it enters the heater or its attached electrical box.

joeford said:

The installation instructions call for a 10 gauge hard wired.

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If the installations call for hardwire, then you must hardwire the unit.

Max 30 Amp

Just to clarify....The specs state "Maximum 30 Amp fuse" and reflects the heater to be 20.9 Amp.

I had assumed that this means you must not exceed 30amp breaker (fuse) but that any amperage over the 20.9....say 25amp breaker would be allowable. Is this not the case?

I also note from the second email that we have some differences of opinion as to using a pigtail irrespective of the gauge....Do I need a third opinion to break the tie?

joeford said:

Just to clarify....The specs state "Maximum 30 Amp fuse" and reflects the heater to be 20.9 Amp.

I had assumed that this means you must not exceed 30amp breaker (fuse) but that any amperage over the 20.9....say 25amp breaker would be allowable. Is this not the case?

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I think I remember someone once saying circuits should operate at no more than 80% of capacity, and that would be 24 amps in a 30-amp circuit. So, I believe 30 would be best ... and again, be sure any plug you buy is going to fit into your outlet since different amperages have different blades and configurations.

joeford said:

I also note from the second email that we have some differences of opinion as to using a pigtail irrespective of the gauge....Do I need a third opinion to break the tie?

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If you will be dealing with a permit and inspector, he or she will ultimately decide. But, maybe there is some kind of code saying you cannot have a cord coming down from a mounted heater ... and the bottom line is always safety. If necessary, maybe you could add an extension to the existing outlet box and run some conduit on the wall and over to the heater while still having the outlet available right where it is for the air conditioner.

Gotcha on the 80%

I think I would prefer to use a pigtail if I can find the right capacity...because from a safety perspective, if I only have one outlet, I can not accidently overload the circuit by having two appliances connected at once...

We may be selling in a year or so, so if there is only one outlet....I can take the heater with me and feel good that the future owner is only connecting the ac to the outlet....well within capacity...Thanks for the insight....

The code issue's simple: installations must conform to the manufacturer's instructions. So if the instructions say hard-wired, a pigtail's illegal. No exceptions.

That means if ever something goes wrong with the heater, you're screwed on the warranty, and if it starts a fire or something, you're screwed on your insurance.

Just set up a 30 amp subpanel - run 2 circuits off it, each 30 amps - one to the receptacle for the AC, one hardwire run to the heater. That way your ass is covered.

Edit: Or, return the heater, and try to find one that's manufacturer-approved for pigtails. (I have no idea if such exists, though.)

joeford said:

... from a safety perspective, if I only have one outlet, I can not accidently overload the circuit by having two appliances connected at once...

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Assuming the wire size matches the circuit breaker, that is not a safety issue. In the fab shop where I work, we have a total of seven outlets in various places for welders and such, but the circuit will only handle two at a time ... and there is never more than two of us working in that area at one time.

Put an extension on the box and run some flexible conduit. All of that could easily be removed along with the heater later.

outlet

What kind of receptacle is it? If it is the same as a dryer outlet, then many items that are recommended to be hard wired, such as dishwashers and cooktops are often connected with a pigtail in order to comply with the requirement that a disconnect be accessible and visible.

hj said:

What kind of receptacle is it? If it is the same as a dryer outlet, then many items that are recommended to be hard wired, such as dishwashers and cooktops are often connected with a pigtail in order to comply with the requirement that a disconnect be accessible and visible.

Click to expand...

But their instructions allow pigtails as an alternate.

...and actually, Lee's last suggestion makes sense, too. The worst that could happen, if somebody was to tun the heater same time as the AC, is the breaker would trip.

...unless the instructions call for a dedicated circuit - then you have to spilt them via a subpanel.