EVSE powered 7.5KW garage heater
- Thread starter dcg9381
- Start date
But....why?
Firebrick43
Well-known member
He found a way to make electric resistance heat(the most expensive heat already) even more expensive than it already is.
mike93lx
ALLIANCE MEMBER
mike93lx
ALLIANCE MEMBER
Outputting straight ac is all it does anyway. The car does the inverting.
Ok
But wouldn't it still mess with the logic? Or just pump 7.5kW?
Guess I don't get the point of the evse and not just a plug
mike93lx
ALLIANCE MEMBER
There is no logic beyond telling it what the max it can output is. That's in the car.
The point feels like a "because I can" and a "because I have a youtube channel" combo, plus it avoids needing to run another circuit
Well my 401k hasn't been great lately so the new plan is getting an evse and plugging various things into it for YouTube.
Stay tuned, I think I'll start with the microwave full of glowsticks
mike93lx
ALLIANCE MEMBER
I'll click on your vids
Sweet.
I figure after a few episodes of me letting the magic smoke out I'll switch it up to review pool shed construction. Want to be a guest star?
mike93lx
ALLIANCE MEMBER
I'm honored
American Locomotive
Well-known member
He actually discusses it right in the first few minutes of the video. He said it basically came down to that fact he didn't want to run another circuit, the NEMA 14-50 plug for the EVSE is just not designed to be regularly plugged/unplugged, and it seemed silly to not be able to utilize the very easy to use, high output 240v cord that's already there.
Huh, the OP was showing as a pic, not the usual YouTube vid, So I never clicked
BUT
Since when is a 14-50 not designed to be unplugged?
American Locomotive
Well-known member
Hey there, I didn't say it wasn't designed to be unplugged. I said regularly plugged/unplugged.
NEMA 14-50 outlet/plugs are really designed for a kitchen range or oven that needs to be unplugged once every 20 years when you replace it. They're awkward to use and kinda sketchy with how close their giant contacts are to the edges. They're just not a great design for something that is to be unplugged regularly. They also tend to wear out fast - I have seen so many slightly crispy and melty NEMA **-50 series plugs.
The J1772/J3400 EV plugs on the other hand are rated for minimum 10,000 plug/unplug cycles. They also have shielded pins making them safer, and are much easier to connect/disconnect.
johnre
Well-known member
There's a reason we have different sizes / rating for 240 V NEMA power connectors - so something doesn't get plugged in to an inadequate electrical service and overload the circuit. In other words, you are physically limited by the connector type on the receptacle side; if what you want to plug in would cause an overload, you physically can't even make the connection short of making a cheater cord.
But SAE-J1772 has no such mechanical connection safeguards; rather, it's entirely in the handshake between EVSE and vehicle instead - you plug it in, the EVSE tells the vehicle the maximum current that it can deliver, and the vehicle is supposed to limit its current draw to that maximum capacity
With an EVSE and this kind of heater, the heater has no such current limiting mechanism, nor can it even know what the maximum is that the EVSE tried to tell it. This circumvents the safeguard.
To be honest, he does get into this issue around the 18 minute mark in the video.
The other issue is that the heater has certain mounting requirements for stand-off distances from walls, room size, etc. It's 7.5 kW capacity. The location should be well thought out, and the heater mount permanent. Making it portable in this way will encourage abuse.
But SAE-J1772 has no such mechanical connection safeguards; rather, it's entirely in the handshake between EVSE and vehicle instead - you plug it in, the EVSE tells the vehicle the maximum current that it can deliver, and the vehicle is supposed to limit its current draw to that maximum capacity
With an EVSE and this kind of heater, the heater has no such current limiting mechanism, nor can it even know what the maximum is that the EVSE tried to tell it. This circumvents the safeguard.
To be honest, he does get into this issue around the 18 minute mark in the video.
The other issue is that the heater has certain mounting requirements for stand-off distances from walls, room size, etc. It's 7.5 kW capacity. The location should be well thought out, and the heater mount permanent. Making it portable in this way will encourage abuse.
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