DIY Home Improvement Forum banner

Breaker and wire size for electric garage heater

1992 Views 8 Replies 6 Participants Last post by  Shadow99
I'm installing one of the heaters below in my garage. It's 240v 4800w and will be aproximatly 25' of wire from the panel to the heater. My plan is to use a 20 amp double pole breaker, #12 thwn in conduit to a junction box with a double pole switch then a short peice (maybe 18") of 12-3 mc between the box and the unit. Is that an acceptable method or should I be using a 30 amp and #10? I probably don't need the switch but I want to keep others from using the breaker as a disconnect.

Thanks in advance for any advice.
1 - 9 of 9 Posts
#10 @ 30 amps with disconnect unless OCPD is within sight and less than 50' away.
Thank you. I will use #10. I forgot you don't want to pull 100% of the available amperage for very long.
#10 @ 30 amps with disconnect unless OCPD is within sight and less than 50' away.
What kind of disconnect? Is a simple wall plug a disconnect?
@John Hook it's a 6 year old thread. But to answer your question, no a simple wall receptacle on a 30 amp circuit does not fall into a category as a "disconnect". Generally a pull disconnect is advised.
A receptacle and cord cap are considered a disconnect. A simple 30A 2-pole switch would be much cheaper.
I only mentioned it due to the resistive load weakening the plug/receptacle connection over time. A direct disconnect or switch as you mention would be more viable.
Disconnect isn't required anyways under CEC.

Simple AC pull style may be handy, but flipping the breaker works fine up here.
  • Like
Reactions: 1
1 - 9 of 9 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.