So I have a standard 240v 30 amp plug in my garage.




I would like to be able to use this 6P plug (my heat treat kiln) are which I believe is max 13 or 15 amps. Previous space had a dedicated outlet.



Is it possible just to make a conversion cord with some kind of circuit breaker and it to plug directly into a 30 amp outlet?



*** Separately, how long of a 240 V 30 amp extension cord can be made in general? Using a 3 hp single phase 240 V motor on it? (10 ft already on the motor.)

Thank you for your thoughts!

This looks like it would do it:

https://www.amazon.com/10-30P-...22bcb241-spons&psc=1

Are those truly compliant? The female side looks close, but …

So, if the kiln shorts a heating element, do we have an issue with the mismatch in the current ratings?

Kiln says 13 amps. (Iirc, Used to be on a 15 or 20 amp circuit.)

You can always put in a smaller breaker.
As for the plug I would just buy it and cut off the old one.
The pig tail will be a pain in the but being pointing upwards.

It sounds like you’re recommending changing the plug/cord on the kiln?

Otherwise, I should clarify that I need to keep the wall outlet as it is for another 240v tool.

Just want to be able to plug in the kiln for the occasional heat treat cycle, which is usually fairly short. 30-60 mins. (Takes time to get hotted up to 1500-2000F, soak time is far less.)

Cut off the kiln plug and add a plug that matches your outlet. Home Depot 30$ maybe. As for the breaker if your kiln pulls 15amp it would be fine. As mentioned if it failed and pulled more current it will still break at 30amp.
If you want a longer cord go bigger gauge wire.

quote:

Originally posted by SIGnified:
Are those truly compliant? The female side looks close, but …

So, if the kiln shorts a heating element, do we have an issue with the mismatch in the current ratings?

Kiln says 13 amps. (Iirc, Used to be on a 15 or 20 amp circuit.)

Breakers protect the wiring in the house, not the end item. The 30amp circuit will continue fat dumb and happy while 15 amp wire starts to melt. There usally is some kind of fuse in the end item. This is just the way it is. That is one of the reasons undersized extension cords are frowned upon.

quote:

is it possible just to make a conversion cord with some kind of circuit breaker and it to plug directly into a 30 amp outlet?

Yes

You can buy a fusible disconnect with 20 amp fuses.

Buy a cord that will plug in to your 30 amp outlet this then gets wired to the top of the disconnect the fuses will protect the kiln

Hang the disconnect on the kiln or a wall nearby

At the bottom side of the disconnect you can direct wire to the kiln or hang an outlet under it to plug the kiln in to.

Plug and un plug at the 30 amp outlet as needed

It looks like your wall receptacle has been arcing (white residue).
I'd pull it out and inspect it.

Then buy a dryer cord, breakered disconnect box, 20 amp breaker and a 20 amp receptacle.

Wire the cord to the box. Gets you from the wall to the disconnect.
Drill a hole for the receptacle to fit in the disconnect cover. Wire it to the box.

Now you'll have a box to plug into the wall and an outlet in the box to plug in your kiln.

* breakers are to protect wiring.
** they are also there to protect end wiring.
*** equipment fuses protect wiring within the equipment.

The fuses in the equipment CAN NOT protect the external wiring from physical damage.

Thank you all for your input… I think I’ve learned what I needed. Solid!

Re: mark on outlet; good catch! I think that’s simply drywall from installing the outlet recently. (That plug has never been used.)