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Upgrading NEMA 14-50 to HPWC
- Thread starter Mikey122687
- Start date
What about installing on the same circuit and get 40 amps charging with the hpwc
eprosenx
Active Member
Wow, yeah, you have zero space.
You are correct. They don’t make a 60a quad tandem.
The Wall Connector can just use the 50a circuit with a 40a charge rate. Obviously you would prefer a 60a circuit, but that could get more spendy.
What is the breaker capacity that feeds that panel? Presumably outside? I bet it is 125a max. A 60a circuit might also be pushing it if it is only a 100a feed or less (though your other loads are pretty small).
Swapping the panel could be an option. They are stupid cheap without main breakers, but that may require some Sheetrock repair.
I am not proposing this, but some might swap some AFCI breakers to non AFCI which would let you use tandems.
Did you get the Wall connector for free? For a short time they sold a plug in version of it that did 40a on a 50a circuit which would not require any modifications to your power setup.
Some have also installed their own pigtails on the Wall Connector to plug in, but I am generally not a massive fan with that route. But for your use case it might be very practical if the wall connector was a freebie. There is some debate as to if this meets code.
This is the cheap and easy solution, you will gain 25% charge speed not the full 50% , but is super easy and no additional expense.
eprosenx
Active Member
Wow, yeah, you have zero space.
You are correct. They don’t make a 60a quad tandem.
The Wall Connector can just use the 50a circuit with a 40a charge rate. Obviously you would prefer a 60a circuit, but that could get more spendy.
What is the breaker capacity that feeds that panel? Presumably outside? I bet it is 125a max. A 60a circuit might also be pushing it if it is only a 100a feed or less (though your other loads are pretty small).
Swapping the panel could be an option. They are stupid cheap without main breakers, but that may require some Sheetrock repair.
I am not proposing this, but some might swap some AFCI breakers to non AFCI which would let you use tandems.
Did you get the Wall connector for free? For a short time they sold a plug in version of it that did 40a on a 50a circuit which would not require any modifications to your power setup.
Some have also installed their own pigtails on the Wall Connector to plug in, but I am generally not a massive fan with that route. But for your use case it might be very practical if the wall connector was a freebie. There is some debate as to if this meets code.
Were one to do what I did not suggest above, one might use this breaker: Eaton BR 1-15 Amp 2 Pole and 1-20 Amp 2 Pole BQC (Common Trip) Quad Circuit Breaker-BQC215220 - The Home Depot Replace the quad tandem and move two AFCI 15a breakers to the outer poles.
Again, I would not suggest such a thing (though the vast majority of houses out there don't have AFCI breakers). ;-) Note that again, there might be more serious load issues with trying to install a 60a breaker anyway.
Running the Wall Connector at 40a on a 50a circuit is likely more than sufficient (if you even have enough load calculation headroom to do that - you should run a load calc before moving from the 32a UMC Gen 2 to a Wall Connector set to 40a).
How do I run a load calc?
I also have a gen1 UMC running 40a and every now and then I keep getting “charging interrupt”. Now I’m suspecting that it can’t do 40a
Wow, yeah, you have zero space.
You are correct. They don’t make a 60a quad tandem.
The Wall Connector can just use the 50a circuit with a 40a charge rate. Obviously you would prefer a 60a circuit, but that could get more spendy.
What is the breaker capacity that feeds that panel? Presumably outside? I bet it is 125a max. A 60a circuit might also be pushing it if it is only a 100a feed or less (though your other loads are pretty small).
Swapping the panel could be an option. They are stupid cheap without main breakers, but that may require some Sheetrock repair.
I am not proposing this, but some might swap some AFCI breakers to non AFCI which would let you use tandems.
Did you get the Wall connector for free? For a short time they sold a plug in version of it that did 40a on a 50a circuit which would not require any modifications to your power setup.
Some have also installed their own pigtails on the Wall Connector to plug in, but I am generally not a massive fan with that route. But for your use case it might be very practical if the wall connector was a freebie. There is some debate as to if this meets code.
I bought the signature wall charger thinking that I could swap the 50a breaker to 60a. After looking at the box I realized that I might not have the option to do it. I’m not sure if the breaker outside is 125 or 100. I’ll take a look tomorrow. But I’ve been having some charge interrupt issue with gen 1 UMC. It would charge for about an hour or so before shutting off and restarting. It could mean that the panel can’t handle the 40a gen1 UMC
eprosenx
Active Member
There are various tools online for running a NEC load calculation. Some jurisdictions have posted pdf files and such with the form.
Btw, most places now follow 2017 NEC but not everywhere. I don’t think the formula has changed much lately.
Hrm, I am not sure what exact error messages from the Tesla to expect. Normally if it detects a voltage issue and either slows down charging or stops altogether I think it gives a more descriptive error message.
This is concerning though, there is a good chance you have a pretty small electrical service.
While it is very modern and looks well done, it may just be too small. I assume this is a condo or townhouse?
Also, if you have the skills to safely do it, I would like to see a picture of the inside of the panel and especially any stickers with detailed specs of the panel on them. Usually inside the door of the panel has lots of data. I particularly want to know what the wire gauge and type (copper or aluminum) feeds this panel if you can see the labels on it. (We can tell type by the color of the stripped wire). A picture of the outdoor unit would be good also (specifically of the breaker size as well)
P.S. Where did you get the UMC Gen 1? I assume we are talking about charging a Model 3 here? Just curious, it should work just fine!
I got the UMC Gen 1 from a friend. Yes it’s for a model 3.
This is the error that I got, there is no error on the car just on the phone.
My place is a townhouse. I’ll remove the panel tomorrow after work so you can see the wiring.
There are various tools online for running a NEC load calculation. Some jurisdictions have posted pdf files and such with the form.
Btw, most places now follow 2017 NEC but not everywhere. I don’t think the formula has changed much lately.
Hrm, I am not sure what exact error messages from the Tesla to expect. Normally if it detects a voltage issue and either slows down charging or stops altogether I think it gives a more descriptive error message.
This is concerning though, there is a good chance you have a pretty small electrical service.
While it is very modern and looks well done, it may just be too small. I assume this is a condo or townhouse?
Also, if you have the skills to safely do it, I would like to see a picture of the inside of the panel and especially any stickers with detailed specs of the panel on them. Usually inside the door of the panel has lots of data. I particularly want to know what the wire gauge and type (copper or aluminum) feeds this panel if you can see the labels on it. (We can tell type by the color of the stripped wire). A picture of the outdoor unit would be good also (specifically of the breaker size as well)
P.S. Where did you get the UMC Gen 1? I assume we are talking about charging a Model 3 here? Just curious, it should work just fine!
So the main electrical panel for the building is outside and locked. I don't have access to go see if it's pushing 125a or 100a into my house but i was able to take some pictures of the panel in my garage.
davewill
Active Member
You could always do a subpanel. Move the EV circuit and two of the other circuits into the new subpanel, and feed it with a new 80a circuit and breaker you run from here. If all of them are in the garage and you can put the subpanel there, that would be a good idea... That said, personally, I don't think the fuss and expense is worth the extra 8a of charging capacity and I would just use the existing 50a circuit.
Edit: That ground wire you're running with the EV circuit looks a bit undersized to me although it's hard to make out in the photo. Make sure you can even use that size ground wire with a 60a circuit.
Edit: That ground wire you're running with the EV circuit looks a bit undersized to me although it's hard to make out in the photo. Make sure you can even use that size ground wire with a 60a circuit.
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eprosenx
Active Member
Thanks. Those look like aluminum conductors feeding this panel (aluminum handles less current for the same size wire than copper).
Were you by chance able to see what wire gauge is labeled on those? I can not quite tell from the pictures and I am not good enough at identifying them just by looking at them.
We definitely still want to know what the main breaker is and also see a picture of the door of your panel to see all the panel specs.
Yea, I've been doing more research on this and it seems like getting extra 8a of charging isn't worth the hundreds of $$$. Not to mention I would need to cut a hole in the wall for a new sub panel. I'm probably will just install the HPWC on top of the 50a breaker or not at all.
Apparently, i don't have access to the electrical room outside the building. I'll email my HOA to see if they can let me in to take pictures. Also my electrician that installed the NEMA 14-50 confirmed that the wire used is 6Gauge.
Here is the current set up. I was thinking of installing the signature wall charger about 12" to the left of the panel to make it looks "pretty".
Apparently, i don't have access to the electrical room outside the building. I'll email my HOA to see if they can let me in to take pictures. Also my electrician that installed the NEMA 14-50 confirmed that the wire used is 6Gauge.
Here is the current set up. I was thinking of installing the signature wall charger about 12" to the left of the panel to make it looks "pretty".
jlv1
Twice as much fun
I'm going to be faced with a similar problem. I ran a 50A circuit (6 gauge) into my garage and installed a NEMA 14-50. I have my UMC1 permanently sitting there to provide 40A charging to the cars.
But now I'm getting a Signature HPWC as a referral reward. I'm wondering if I should replace the 14-50 outlet with the hardwired HPWC (but limit it to 40A). I'm mostly concerned about reports of the UMC1 melting (such as this: PSA. Another melted NEMA 14-50 receptacle). This is why I've not unplugged the UMC1 since we got the UMC2 with the X.
But now I'm getting a Signature HPWC as a referral reward. I'm wondering if I should replace the 14-50 outlet with the hardwired HPWC (but limit it to 40A). I'm mostly concerned about reports of the UMC1 melting (such as this: PSA. Another melted NEMA 14-50 receptacle). This is why I've not unplugged the UMC1 since we got the UMC2 with the X.
juliusa
Active Member
My suggestion is HPWC at 50a. I would not put in a larger breaker without doing a load calculation first, but my guess is it would come back ok.
If you really want a larger breaker, put in two doubles on one side to handle the 4 15a circuits at the bottom of the panel if you can get AFCI doubles. Put in a new 60a breaker in the freed up space, and then either leave the 50/20 breaker you are using currently with nothing connected to the 50, or better just get a new 20a breaker (or put back in the one you took out when you added the 14-50).
Edit: looks like AFCI tandems are not available.
If you really want a larger breaker, put in two doubles on one side to handle the 4 15a circuits at the bottom of the panel if you can get AFCI doubles. Put in a new 60a breaker in the freed up space, and then either leave the 50/20 breaker you are using currently with nothing connected to the 50, or better just get a new 20a breaker (or put back in the one you took out when you added the 14-50).
Edit: looks like AFCI tandems are not available.
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you could also do a pig tail from HPWC to 14-50 so if that fails you can still use your UMC. Having 40A is better than 32A and wont cost you anymore money.. But as mentioned, easiest/cheapest is hard wire and set to 50A breaker (number 8) for max of 40A . Not worth the hassle and money to upgrade your panel for extra 8A.
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I'd also suggest HPWC set at 40A with the dip switches (you set it at 80% of the rated circuit).
@Mikey122687 You should look at the voltage the car is reporting while charging. My guess is that it's low, i.e. your wires are heating due to either improper sizing or a non-ideal/loose connection in the path. If the voltage drops too much, Tesla will fault, as a safety measure.
@Mikey122687 You should look at the voltage the car is reporting while charging. My guess is that it's low, i.e. your wires are heating due to either improper sizing or a non-ideal/loose connection in the path. If the voltage drops too much, Tesla will fault, as a safety measure.
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