Extension cord for 5000W electric heater.

[3rdgendslmech]

I recently purchased a Comfort Zone electric heater from tractor supply. Love it for what it is but without a ceiling and insulation it's only going to do so much. Planning on putting up a metal ceiling and 12" of blown in insulation.
Ive got it mounted on the ceiling blowing where my toolbox and work bench are.
Can I take the MC cable, unhook the heater and install a 30 amp twist lock or a electric drier receptical. Then buy about 35-40' of 10/3 SOOW cord and have it so the heater could be moved around? I've got an old dump truck rim with a 2" square stock cemented in the middle of it, was gonna make an adjustable hanger for the heater.
Is this something that will work? Should I use 8/3 instead? On 5000W setting the heater only pulls about 21 amps.

 

[wyliesdiesels]

Not sure about the M/C cable youre referring to. Are you saying the heater is hardwired with M/C cable?

For a plug and receptacle, you need a NEMA 6-30 NOT a dryer receptacle which is 10-30 or 14-30.

Did the heater come with a cord and plug?

Which model is it?

 

[3rdgendslmech]

It's the CZ220 Wylie. It didn't come with M/C (armorlite metal clad) but I had about 8 feet that a guy at work had given me so I ran it direct from the breaker panel to the heater.
I didn't think I'd want a drier type plug. I seem to remember an older guy telling me you want twist locks for extension cords because they're laying on the ground and could be caught on something and unplugged.

 

[wyliesdiesels]

It's the CZ220 Wylie. It didn't come with M/C (armorlite metal clad) but I had about 8 feet that a guy at work had given me so I ran it direct from the breaker panel to the heater.
I didn't think I'd want a drier type plug. I seem to remember an older guy telling me you want twist locks for extension cords because they're laying on the ground and could be caught on something and unplugged.

what gauge is the M/C?

And you can get straight blade and twist lock in almost every style plug. That is up to you if you want twist lock but regardless a dryer plug(10-30 or 14-30) is the wrong plug to use.

 

[3rdgendslmech]

what gauge is the M/C?

And you can get straight blade and twist lock in almost every style plug. That is up to you if you want twist lock but regardless a dryer plug(10-30 or 14-30) is the wrong plug to use.

10 gauge

 

[matt_i]

#10 awg SO-cord will run your 5kw all day long. Its more about damaging the exterior jacket of the cable and your ability not to dump the post over. A "J" = junior cord is 300v rated, thinner jacket, no-J is a 600V rated cord with a better jacket.

 

[alfredeneuman]

The #10 cord could be as long as 70' and the voltage drop would not exceed the suggested limit (3%)

 

[theoldwizard1]

In general, portable cordage is always stepped up one size, probably as a "safety" factor. This is why if you buy a 12/3 extension cord it will typically say it is good for 15A where as 12/2 NM-B is rated for 20A.

 

[sberry]

It is typically rated 15 due to the end that comes on it, even 10 cords are rated 15.

 

[exranger06]

The owner's manual for that heater says, "This heater is designed to be directly wired to 240 volt electric power. Never use with an extension cord or relocatable power tap (outlet/power strip)."

Just sayin.
https://www.tractorsupply.com/static/sites/TSC/downloads/ProdContentPDFs/1030776_Man1.pdf

 

[theoldwizard1]

It is typically rated 15 due to the end that comes on it, even 10 cords are rated 15.

Good point ! I still contend that it is a "flaw" in the NEC that you are allowed to put a NEMA 5-15 outlet on a 20A circuit. When I wired my sons garage, all 20A circuits had 5-20 outlets, even the GFCI. Definitely cost a few dollars more.

 

[sberry]

The end is not really different in capacity but the recept is designed to limit access to general circuits by tools that have the possibility of tripping the circuit. In some sense it is a calculated load like many circuits are. Often 20 ends are used on lighter tools, often in janitorial where you do not want the janitor plugging in to computer, science experiments with hi draw, hi start or even adding aditional load to multi outlet circuits that may be in use. Put a 20 end on it,, even on 14 and 16 cords and provide a dedicated outlet.
A 20 recept simply says,,, ok to plug heavy tools on this circuit. Same capacity as other circuits but is usually intended (when installed under proffesional design) is dedicated. Its not to deliver more current but to tell the operator something or prevent it by design.
The 15 simply limits access ti that circuit. It's kind of amateur to put 20 everywhere.

 

[sberry]

The janitor at the school ss a baby vac, a consumer grade deal with a common cord. It had been changed after to a 20 end,,, which she had twisted ti allow it on 15,, ha. Nut it was an after marked end installed ny a real electrician just to prevent its use on the lab circuits. The tool did not "need" 20A. Very few tools come 20, most cases they are changed to it.
Its not a "flaw" in the code but a very deliberately designed feature and system.

 

[sberry]

Almost all,,, and I use that term as a loophole,, but really about the only time a breaker is designed to provide thermal protection in common circuits is to prevent overload of wires to circuits with multiple outlets.
When we see multi taps,, a 3 way or a power strip it has additional breaker protection so combination loads do not overload the wire. A 3 way or strip with number 12 does not need it.
Any single appliance that comes with a 15 end will not overload the circuit wire. A 20A breaker on a single outlet 20 isn't really for thermal,,, it will,,, but its intent is simply off/on and short circuit, similar to a dedicated circuit with a calculated load.
Welders carry this to an extreme with duty cycle and allow smaller wire, an air conditioner may follow this, 12 wire, 40 breaker, load limited by the draw of the appliance and in some cases further protection, motors are often like this. Breaker in the device,,, similar to the power strip actually protects the wire ahead of it.

 

[3rdgendslmech]

I put all 20 amp recepticals in my barn. Anywho....as far as upsizing the cord, I've seen on a few things that say stranded wire 12ga solid wire 14 gauge. Makes sense because solid wires of the same gauge carry the load better.
What I planned on doing was running a short whip from the heater long enough to go down the stand and connect at the floor.
Also, could I use a NEMA L15-30 plug and connector, give up the neutal wire at the heater. Was thinking about this route because it would be kinda nice to leave my generator in the shed running vs putting it on the porch of the house.

 

[Toothaker]

The owner's manual for that heater says, "This heater is designed to be directly wired to 240 volt electric power. Never use with an extension cord or relocatable power tap (outlet/power strip)."

Just sayin.
https://www.tractorsupply.com/static/sites/TSC/downloads/ProdContentPDFs/1030776_Man1.pdf

Tap tap tap. Is this thing on?

I like how the discussion just flows around this post, like it never happened. [emoji2]

Sent from my mobile using The Garage Journal mobile app

 

[wyliesdiesels]

Tap tap tap. Is this thing on?

I like how the discussion just flows around this post, like it never happened. [emoji2]

Sent from my mobile using The Garage Journal mobile app

people choose to ignore codes and manufacturer instructions that disrupt their plans

 

[Skiff Builder]

Tap tap tap. Is this thing on?

I like how the discussion just flows around this post, like it never happened. [emoji2]

Sent from my mobile using The Garage Journal mobile app

Would it be acceptable for the OP to use say, a 20' whip of the proper current carrying capacity so the unit could be moved around?
Seen portable elec heaters 480V with 25' SO cords.

 

[Skiff Builder]

Tap tap tap. Is this thing on?

I like how the discussion just flows around this post, like it never happened. [emoji2]

Sent from my mobile using The Garage Journal mobile app

people choose to ignore codes and manufacturer instructions that disrupt their plans

Wylie, I'm all for doing it right when it comes to electricity. The words substituted below popped right into my head when reading your last.

people choose to ignorexxxxx speed limit signs and xxxxxxxx speed advisories that disrupt their plans.

I know no one on GJ ever exceeded a speed limit

But seriously, DO electric work properly.

 

[sberry]

There could be several reasons its hard wired only semi related to the cord itself. It may lack features to make it safe as a portable.

 

[sberry]

Would it be acceptable for the OP to use say, a 20' whip of the proper current carrying capacity so the unit could be moved around?
Seen portable elec heaters 480V with 25' SO cords.

There may be reasons other than the cord, semi rated but they list it for hard wire due to the fact it doesnt have all the safety features for portable.
A unit with 480 is likely under professional supervision, not really diy consumer stuff

 

[alfredeneuman]

Would it be acceptable for the OP to use say, a 20' whip of the proper current carrying capacity so the unit could be moved around?

No, any conduit that long must be secured.
(I think I read in the Code that the maximum length for an unsecured whip was 6', but I'm not sure)