Op is in Chicago. They have their own code over there. They use a lot of conduit.
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Replacing 50 amp breaker with 60 amp?
- Thread starter MatildaModelY
- Start date
Charger is actually in WI, and is more lax than chicago when it comes to code.
Hello guys, I have 60a breaker with NM-B 6/3 wired (didnt know this wire is for 50a breaker till recently).
after I found out the 6/3 wire is only for 50a breaker I've lower the charing amp to 40 or lower. my question is should I replace the 60a breaker to 50a since the wire is for a 50a breaker or its fine as long I lower the charing amp to 40 or lower.
Thank you
after I found out the 6/3 wire is only for 50a breaker I've lower the charing amp to 40 or lower. my question is should I replace the 60a breaker to 50a since the wire is for a 50a breaker or its fine as long I lower the charing amp to 40 or lower.
Thank you
If the wire will only support a 50 amp breaker, then you should replace the existing 60 amp breaker with a 50.
Technically the wiring itself is rated for 55A and per NEC rules a 60A breaker is acceptable in that scenario (assuming this is a hard wired device and not hooked up to a 14-50 or 6-50). The charger would still have to be limited to 44A or less to meet the 80% rule.
Does that mean as long I keep it below 44a should be fine with the 60a breaker?
Thanks
ATPMSD
Active Member
Assuming you are talking about a Wall Connector, the Wall Connector should be set to 50-amps. The connector will not draw more than 40-amps at this settling.
ATPMSD
Active Member
There was a discussion on this subject, which I cannot locate at the moment, but as I recall you cannot use a 60-amp breaker with 55-amp wire unless the connected device is hardwired and will never draw more that 55-amps, so the Wall Connector cannot be set to 60-amps. As you will be setting it to 50-amps you need to use a 50-amp breaker.
Yes, you really should because you should have something pretty solid to enforce the right amp limit. So my second question comes to HOW are you lowering the amp limit? That setting where you can lower the amps from the touch screen in the car (or mobile app) is really not very reliable, so you shouldn't count on that. Reconfiguring a wall connector to a 50A circuit is much better, but you should still probably switch the breaker too.
If you can find a device that really lets you SET it for a 44A limit, then yes, that would be an appropriate thing, but it is extremely rare to find a car charging device that has a setting at that amount. And no, just turning it down to that level on the car's screen doesn't cut it. The cars can forget that setting and default back to max for a few reasons that aren't uncommon (GPS glitching, firmware updates, etc.).
Trying to fudge your way around these things just isn't a good idea. Fix the circuit to a 50A breaker to be correct all the way through.
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is also normal while charging the car it has a slight noise came from the panel with that breaker, If I use 48a it will be little louder compare to 40a I have to put my whole head over i will still hear a little buzz sound. don't know replace the breakers will fix the issue. I have called an electrician he told me to change a new panel because my panel seems old should replace a new panel.
ATPMSD
Active Member
If you are sure it is the charging breaker try this if you are comfortable doing so. Open the panel, trip the breaker and remove it. Gentle blow any dust out and reinstall the breaker. Then tighten the connections but do not close the breaker.
Open the Wall Connector and see if the connections can be tightened (likley). Put in back together, close the breaker and see what happens.
Sigh.. another 'professional', probably advising totally unneeded work. 'seems old' just isn't a justification to change a panel for 1-2k(or subpanel for $500). The justification might be 'there are no new breakers available for this panel' or 'the bus bars are corroded'.
You most likely have a circuit breaker needing replacement, either the one directly feeding the charger or the main breaker(not possible, since your noise is in a subpanel and there shouldn't be a 'main' breaker inside the subpanel)
A new 50 amp duplex non-gfci breaker is usually $20-30.
If he has a wall connector set to 40A, why would a 60A breaker be not to code using 6AWG NM/B?
ATPMSD
Active Member
If you are trying to fix a “noise” issue you should find the problem and fix it, not just lower capacity to avoid the noise.
ATPMSD
Active Member
The breaker protects both the wire and “appliance.” In this case it should match the appliance rating. In the case of the Wall Connector if you set it to a 50-amp circuit, it will draw no more than 40-amps, but you use a 50-amp breaker since that is what the connector is set it to.
