Ugghhh ... Discovered a wiring problem in my home - help...

[cdherman]

So I bought one of those refurbished clipper creek EVSE's off eBay. But I went with the CS-60 since I *thought* I had a 100A service to my garage and could add a 60A circuit. The CS-60 pulls a max of 48A. My idea was "future proofing"......

So today I get to looking and realize that the prior owner appears to have fed the 100A service with 6-3 NM wire. I had never looked, just assumed that the 100A breaker at the main service was correct.

That means what I really have is a 60A subpanel and I need to switch out the 100A breaker at the main.

But can someone help me -- can I still put a 60A beaker in a subpanel that is rated only at 60A? I assume yes, but the problem could be that someday, when someone actually pulls 48A to their model year 2017 Leaf (lets hope!), and then switches on a circular saw and dust collecter, the main 60A breaker back in the house will blow.

And I don't know how to derate the CS-60 -- I mean, it must signal the vehicle somehow that 48A charging is allowed. I *could* just install it on a 40A circuit (only paid $124 more for it). But I would worry about problems down the road when someone actually plugs in a 48A vehicle.

Am I making any sense?

Finally, I seem to recall reading that the wires to an EVSE should be run in conduit since its continuous duty. So technically, I'd need to run size six wire in a conduit from the subpanel to the EVSE. But wait! The subpanel itself is fed with 6-3 plus ground service wire that is NOT in a conduit. It snakes its way through my basement joists, up inside an interior wall, through the attic and down into the garage -- a run of at least 100 feet or more.

In the end, I think I just am not going to be able to use the CS-60... Darn...

Anyone with an idea to save me?

 

[nworbekim]

Hi,

I'm not an electrician, but I believe (and been told by electricians) the purpose of the breaker is to protect the wiring. I'd put in the 60amp breakers unless you intend to replace the cable with something rated for 100amps.

I wouldn't worry about tripping the breaker, the odds of actually using 60amps in your garage is probably small.

Good luck!

Mike

 

[TickTock]

If it were me, I would just put in the 40A breaker and worry about the 60A problem when you actually have it. Even knowing the 40A limitation, I think I would have gone for the bigger unit, anyway for the bigger relays. When I wired my shop, the inspector had no problem with a 200A circuit breaker on a 200A subpanel song side others breakers since it was protected at the main. Looks like #6 is good enough for 60A up to 120 feet so your pushing even 60A.

 

[TimLee]

So today I get to looking and realize that the prior owner appears to have fed the 100A service with 6-3 NM wire. I had never looked, just assumed that the 100A breaker at the main service was correct.

That means what I really have is a 60A subpanel and I need to switch out the 100A breaker at the main.

Finally, I seem to recall reading that the wires to an EVSE should be run in conduit since its continuous duty. So technically, I'd need to run size six wire in a conduit from the subpanel to the EVSE.

Yes, having the 100A breaker feeding 6-3 NM wire is a code violation, and the breaker should be changed out to a maximum of 60A.
I don't know where you got that EVSE supply wire should be run in conduit since its continuous duty.
My Blink was installed by licensed electricians and was code inspected, and it is supplied by NM cable in the wall.
Many of the installations did use conduit for the final run in a garage because it was quicker and cheaper to install conduit, than to cut sheetrock and put NM cable inside the wall, which is required with NM cable.
That would have been the standard install approach on mine, but the wall distance on mine was very short, ~6 feet, and the installers agreed to remove small section of sheetrock and put the NM cable in the wall through holes bored in the studs, if I would do the replacement of the sheetrock.
Keep in mind that an EVSE is considered a "continuous" load. A continuous load is only allowed to use 80% of the circuit's capacity. So if the EVSE can do 48A, the supply breaker does need to be 60A or higher.
I'm not sure about code acceptability of a 60A breaker in a panel fed by a 60A breaker at the main. Not sure it is a violation, but considered bad practice.
But if there's not much as being powered in the garage, it probably will be OK.

 

[Nubo]

So I bought one of those refurbished clipper creek EVSE's off eBay. But I went with the CS-60 since I *thought* I had a 100A service to my garage and could add a 60A circuit. The CS-60 pulls a max of 48A. My idea was "future proofing"......

So today I get to looking and realize that the prior owner appears to have fed the 100A service with 6-3 NM wire. I had never looked, just assumed that the 100A breaker at the main service was correct.

That means what I really have is a 60A subpanel and I need to switch out the 100A breaker at the main.

Or run heavier wire to the subpanel.

But can someone help me -- can I still put a 60A beaker in a subpanel that is rated only at 60A? I assume yes, but the problem could be that someday, when someone actually pulls 48A to their model year 2017 Leaf (lets hope!), and then switches on a circular saw and dust collecter, the main 60A breaker back in the house will blow.

If you install the EVSE on that 60A circuit, it needs to be the ONLY thing on the circuit. Anything else in the garage would need to be on different breaker(s) in the subpanel.

And I don't know how to derate the CS-60 -- I mean, it must signal the vehicle somehow that 48A charging is allowed. I *could* just install it on a 40A circuit (only paid $124 more for it). But I would worry about problems down the road when someone actually plugs in a 48A vehicle.

I believe the J1772 "negotiation" is done with a simple resistor value. You could probably put a different resistor in the EVSE but I'm not sure what that would do to the UL certification, etc.. Probably not kosher.

Finally, I seem to recall reading that the wires to an EVSE should be run in conduit since its continuous duty. So technically, I'd need to run size six wire in a conduit from the subpanel to the EVSE. But wait! The subpanel itself is fed with 6-3 plus ground service wire that is NOT in a conduit. It snakes its way through my basement joists, up inside an interior wall, through the attic and down into the garage -- a run of at least 100 feet or more.

You definitely don't want to combine under-sized wire with a long run.

In the end, I think I just am not going to be able to use the CS-60... Darn...

Anyone with an idea to save me?

Since someone has already played fast and loose with the wiring in your home, I'd consult an electrician. Who knows what else they did or even if the 100 amp subpanel fits into the load calculations for the main service. Keep everything legit. It's not enough to say "well, I'll never really use X, or I'll just remember not to run X and Y at the same time.

My guess you'll either have to compromise on the wiring end by creating a "real" 100A service to the garage, or settle for a less powerful EVSE. De-rating the CS-60, I'm not so sure of.

 

[Randy]

The Clipper Creek unit would have to be reprogrammed to reduce the pilot signal down to 30 amps or 40 amps. Tony had it done by them, it can't be done by the user (that I know of).

 

[smkettner]

Swap in the 60a breaker and get on with your installation.
40 amp Leviton might be better.

 

[cdherman]

Yes, having the 100A breaker feeding 6-3 NM wire is a code violation, and the breaker should be changed out to a maximum of 60A.
I don't know where you got that EVSE supply wire should be run in conduit since its continuous duty.
My Blink was installed by licensed electricians and was code inspected, and it is supplied by NM cable in the wall.
Many of the installations did use conduit for the final run in a garage because it was quicker and cheaper to install conduit, than to cut sheetrock and put NM cable inside the wall, which is required with NM cable.
That would have been the standard install approach on mine, but the wall distance on mine was very short, ~6 feet, and the installers agreed to remove small section of sheetrock and put the NM cable in the wall through holes bored in the studs, if I would do the replacement of the sheetrock.
Keep in mind that an EVSE is considered a "continuous" load. A continuous load is only allowed to use 80% of the circuit's capacity. So if the EVSE can do 48A, the supply breaker does need to be 60A or higher.
I'm not sure about code acceptability of a 60A breaker in a panel fed by a 60A breaker at the main. Not sure it is a violation, but considered bad practice.
But if there's not much as being powered in the garage, it probably will be OK.

OK, been reading all afternoon and yes, seems I was mistaken about the conduit thing -- I suspect it came from some post where someone was being chastized for suggesting a surface run of NM (commonly called Romax), which is a no-no under seven feet, IIRC.

I had intended to run the 6-3 to the EVSE between joists in attic and then down inside the wall, fished.

In the end, I think I can actually do this within code, but someday, should someone actualy plug in an EV capacble of 48A charging, they will just have to understand that aside from some lights, they had better not start runing the power tools (my garage has a shop space in the back).

And, obviously, the 100A breaker in the main service has got to go. Cannot beleive the PO did that. Feel a little dumb myself as well -- I rewired a lot of this house, replacing some other messes the PO left behind, as well as removing ALL the Aluminum wiring from the 60's -- and yet I missed checking the size of the cable going to the subpanel. It is in plain sight in the basement....

I would actually second the suggestion by a couple of posters that a electrician would a wise choice for about 99% of people in my situation. I'm not going to take that advice, but agree that for most folks, its probably the correct way to go.....

 

[QueenBee]

I think you'll be perfectly fine switching the 100 amp breaker for a 60 amp breaker. There shouldn't be any safety issue or even a code issue of then putting a 60 amp breaker in the subpanel for the EVSE. Obviously you'd want a larger service if you were doing this again but considering the EVSE is only going to max at 48 amp that leaves you with almost 12 amps at 240 volt of extra usage before you are in danger of tripping the sub panel breaker. And it's there in case you do start your welder while charging your future EV to trip before damage to the wire occurs.

I see no reason to derate your EVSE unless you wanted to run smaller gauge wire to it.

BTW: Do consider getting your work inspected. It's easy, will be nice when you go to sell the house and IMO when the inspectors know that you know what you are doing they are nice to work with and are pleasant about the corrections they want.

 

[sub3marathonman]

Yes, having the 100A breaker feeding 6-3 NM wire is a code violation, and the breaker should be changed out to a maximum of 60A.

...

Keep in mind that an EVSE is considered a "continuous" load. A continuous load is only allowed to use 80% of the circuit's capacity. So if the EVSE can do 48A, the supply breaker does need to be 60A or higher.
I'm not sure about code acceptability of a 60A breaker in a panel fed by a 60A breaker at the main. Not sure it is a violation, but considered bad practice.
But if there's not much as being powered in the garage, it probably will be OK.

In the end, I think I can actually do this within code, but someday, should someone actualy plug in an EV capacble of 48A charging, they will just have to understand that aside from some lights, they had better not start runing the power tools (my garage has a shop space in the back).

...

I would actually second the suggestion by a couple of posters that a electrician would a wise choice for about 99% of people in my situation. I'm not going to take that advice, but agree that for most folks, its probably the correct way to go.....

I'm not a licensed electrician, but I too think you should consult one.

I don't think you can do this to code as currently proposed just switching to a 60 amp breaker. The garage subpanel will need a load calculation done, and I strongly suspect that it won't pass. And even though you're not pulling the full 48 amps, if the EVSE is rated for it that is what you have to calculate for.

I don't know if this can be done, but what you need is the 60 amp feed into a transfer switch that either powers the one 60 amp EVSE circuit or when switched powers the original subpanel circuits. I suspect the current garage subpanel wouldn't even pass with just another 20 amp 240v circuit added. And if the wiring is aluminum going to the garage, I would definitely call a professional.

I tried to do something unusual when I was putting in my EVSE, with the same justification that it wouldn't be pulling that many amps with the current LEAF, but in the end decided it was better to do things the correct way, even if the code would have allowed a bit of unusual wiring methods. I was able to do this myself due to previous professional electrical work when I had the house built. With unprofessional wiring, done by the previous owner, I would at least want a professional electrician or code inspector to give his approval to any work I did.

 

[cdherman]

A little update:

I decided that the 6-3 run from the main was too much trouble to remove and replace. But I corrected the breaker to 60A and think that the run to the subpanel of about 125 ft should be OK interms of voltage drop.

From the sub-panel in the garage, I put in a 6-3 25' run of NM to my EVSE.. 60A breaker, derated to 48A cont duty.

Of course, it's not perfect. I feel safe living in the house, and if someone raises the issue if/when I sell it, I will simply remove the EVSE and/or breaker and that will be the end of it...

Its true that someone could overload the breaker at the service entrance (main panel) if they tried to charge a 48A EVSE and run some power tools at the same time. They would have to do this on an extended basis before the breaker would blow, as I have 12 A of "intermittant use...

Beats me if what I did is entirely correct. I have dealt with so many "professional electricians" through the years that I know from experience that the answers I'll get from them are just slightly more correct that I can get on the internet. Perhaps worse.....

Thanks again....

 

[QueenBee]

Of course, it's not perfect. I feel safe living in the house, and if someone raises the issue if/when I sell it, I will simply remove the EVSE and/or breaker and that will be the end of it...

Certainly sounds like you did what was needed to make this installation safe and it's easy for someone else to say it's not perfect when it's not their money and/or time that would be needed to make it perfect.


Obviously should have been inspected but to each their own

 

[wwhitney]

I decided that the 6-3 run from the main was too much trouble to remove and replace. But I corrected the breaker to 60A and think that the run to the subpanel of about 125 ft should be OK interms of voltage drop.

From the sub-panel in the garage, I put in a 6-3 25' run of NM to my EVSE.. 60A breaker, derated to 48A cont duty.

FYI, the ampacity of NM cable is limited to the 60C rating and for #6 Cu that is 55 amps. That is commonly protected by a 60A breaker (next standard size up), as long as the calculated load is 55 amps or less. But it is inadequate for a 60A load like the Clipper Creek CS-60. Perhaps not a problem for you in practice, as you are planning to avoid drawing the full 48A from your CS-60 anyway.

Cheers, Wayne