Need some help: King Electric GH-2407

[R_einan]

Decided on electric heat for the shop to keep it above freezing this winter. Went with a King 7500w heater. Specs say 32A on this unit. Wired it in with 8/2 NM-B to a properly sized breaker. Shop runs on a 60a sub panel off the house run with 6awg THFN in conduit. Tried to set up a Aube rc840t-240 to run a remote 24v thermostat, but didn't get boo out of the heater. Removed the relay and required the internal thermostat. When I went to turn the heater on, the whole shop went down. Tripped the heater breaker, main subpanel breaker, and the breaker in the house as well. Not really sure where to go from here, because I have never had a power issue of this degree. Thoughts?

 

[shooon]

How exactly did you rewire the internal thermostat?

Wondering if you maybe inadvertently shorted the control transformer when trying to rewire the thermostat. Can you snap a few pictures and check for a wiring diagram on the inside panel?

Edit:
Also assuming this is a 240v heater?
Have you checked to ensure you are getting 240v at the heater power connections and that they are wired correctly?

 

[R_einan]

https://www.king-electric.com/pdfs/GH_SKB_UniversalIntructions.pdf

I followed the wiring diagram for the remote t-stat exactly. Disconnecting the internal at the terminal block and attaching the 3 wires from the relay to the correct numbered terminals.

I also verified that each leg is being supplied 120V.

 

[R_einan]

After some help from the guys in the electrical sub forums, I checked resistance of the elements and made sure I didn't have a short in the elements. Turns out, I have a short in the internal thermostat. After hooking the relay/transformer back up and disconnecting the internal, I was able to get it running.

 

[shooon]

Awesome!

Glad you sorted it out, thanks for posting back your findings.