Welcome to Tesla Motors Club
Discuss Tesla's Model S, Model 3, Model X, Model Y, Cybertruck, Roadster and More.
Register

Electricians, did I totally miss an opportunity here?

This site may earn commission on affiliate links.
I'm learning as I go (see my previous post in reply to @kkillebrew )... The humidifier has a dip switch and you can select between 11.5 and 16 amps. The electrician was not the same person that installed the humidifier, so my guess is he was being extra safe (not knowing which setting the plumber was going to use)?
any way you can check the gauge of the Romex coming into the outlet box from the basement? or at the breaker in the panel? Should be a thick number 8 for 40 amps and you need to be sure to be safe, depending on the length some might suggest #6. Otherwise with the right plug and the right breaker you are good to go.
 
I'm learning as I go (see my previous post in reply to @kkillebrew )... The humidifier has a dip switch and you can select between 11.5 and 16 amps. The electrician was not the same person that installed the humidifier, so my guess is he was being extra safe (not knowing which setting the plumber was going to use)?

I would not do this stuff myself. But considering you say you have at least 40 amp available going to the humidifier, I ask an electrician to split that circuit with a box that has two circuit breakers at the garage. One for your EV and the other going to the humidifier. Sort of saves the day when you yourself said "did I miss an opportunity". Something this simple would (I think) meet code and easy to make happen.
 
  • Love
Reactions: Rocky_H
This is what I was worried about. So I have these junction boxes that I can't even use :(

How bad is it if I do install a 6-20 plug and charge @ 16 amps though? Am I just violating the code or am I really creating a hazard?

You have 2 types of hazards with the circuit overload - one is using more than 80% of the load, and the other is a short circuit. The short circuit is 100% protected by the breaker no matter what you do (still can get electrocuted), and the other one, using more than 80% has some protection because the circuit breaker heats up and will trip when hot.

Since you cannot have any more short-circuit protection than you already have, I fail to see what additional protection you would receive by having the two dedicated loads on separate breakers, assuming that the load is less than or equal to 32A. You would receive the benefit of having an easier time to diagnose a tripped breaker, but this is different from a hazard.

The biggest hazard would be, if you installed an outlet, that maybe someone will come by and hook up a welder and draw 19A instead of 16A.
 
Ok, I think things are starting to make sense now... I found the installation manual for the humidifier and it says:

"With factory settings, the Model 800 draws 11 .5 amps +/- 10% . Use a minimum 20 amp dedicated circuit when installing to operate at 11.5 amps. When set to 16 amps, use a minimum 25 amp dedicated circuit"

So it looks like it is meant to be a "dedicated circuit". But why then did the electrician add the junction boxes on the way to the humidifier? Is this part of the electrical code? I've heard that 120v outlets inside the house have to be every so many feet... is it the same for this 240v line (even though it's "dedicated" to something already)???
The electrician may have decided it was easier to pull the cable in two sections. Every junction where wires are joined have to be accessible, like in a junction box. You can take the cover off and see if the wires are just passing through or there are wire nuts or other connectors inside. The solution I provided up-thread will definitely work in your specific situation. 40A breaker in the main panel feeding this tiny sub-panel with two 20A 240V circuits, one for the existing humidifier and one for car charging on a NEMA 6-20 outlet.
 
  • Like
Reactions: Akikiki
I think you are making this a bit more complicated than it needs to be.

I would not do this stuff myself. But considering you say you have at least 40 amp available going to the humidifier, I ask an electrician to split that circuit with a box that has two circuit breakers at the garage. One for your EV and the other going to the humidifier. Sort of saves the day when you yourself said "did I miss an opportunity". Something this simple would (I think) meet code and easy to make happen.

The electrician may have decided it was easier to pull the cable in two sections. Every junction where wires are joined have to be accessible, like in a junction box. You can take the cover off and see if the wires are just passing through or there are wire nuts or other connectors inside. The solution I provided up-thread will definitely work in your specific situation. 40A breaker in the main panel feeding this tiny sub-panel with two 20A 240V circuits, one for the existing humidifier and one for car charging on a NEMA 6-20 outlet.

Yes--like this. I wouldn't do it myself, but it would be easy to describe this to an electrician. You have a 40A circuit. Run that to a subpanel, and then split it to two branch circuits to the humidifier and the car outlet. This is still considered separate dedicated circuits if they are done that way, each with its own breaker.
 
  • Like
Reactions: Akikiki
Why? Again, I really don't know what I'm talking about, but if I have 40 amps available and the only other load is the humidifier then I know how much load I have left right? So I should be able to install a 6-20 plug in the junction box for the EVSE no?
Do you think it is a good idea to protect an outlet rated at 20 amps with a 40 amp breaker? The tap rule might let you get away with it, but I wouldn’t.