Is it possible to run the FCSP by combining 2 50amp runs?

[invertedspear]

I am not an electrician, so this question is coming from pure ignorance with a touch of mad scientist.

When I put a charger in the garage, I was planning on getting an SR, and honestly, was just going to use the mobile charger that was included at the time. But I also knew we were eventually going to be a 2 EV family, so when the Electrician ran the wire and installed the 14-50 outlet, I had him run 2 lines on independent 50 amp breakers.

Now I own an ER, and Jeep's EV Wrangler is pushed off to 2028, so I'm thinking I want to go ahead with the FCSP. The kicker is that the charger is 120 ft from the panel, so pulling all the existing copper out and running new lines is going to be expensive. The mad scientist in me says I should be able connect both of these 50 amp lines to a cutoff switch in the garage, then run a single line out of that to the FCSP and run it at 80 amps. In the main panel both lines are coming off breakers on the same rail, one right above the other. Would this work in such a way to not be a hazard? I would think that if one of the lines somehow became disconnected, the overdraw on the other line would trip that breaker and it would still fail safely.

Please tell me if this is a terrible idea or not, or if there's any other way to do this so that I don't have to pull out the existing copper and run a new line.


Thanks!

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[Tfarrell73]

Is it a 23 or 24 ER? The 24 will only charge up to 48 amps. 24 does NOT come with the FSCP. There are a lot of cheaper EVSEs available than the Ford charger.

 

[TaxmanHog]

I think the surviving parallel circuit would overheat quickly and start a fire, not certain the 100 amp breaker would intervene in time to prevent a catastrophe!

 

[Newton]

The breakers would still trip. In theory you could combine the two wires and put in a 100A breaker but doing that safely is probably more trouble than it is worth.

I don't see why buying an ER means that you need that much charging power, if you take a 100 mile trip in an ER it will take exactly (almost) as much energy to recharge as if you had taken a SR. I think your original plan of multiple chargers is best. At the moment I wish I had two, I just took an unexpected trip to Bellingham after a long trip so the Ford is low, and we left the EV6 at a low state of charge as recommended while we were gone and my wife needed to take a trip with it. Now I have two cars at a low state of charge. It is no big deal, they will both be charged by tomorrow but at some point I'm going to have to remember to go out and swap the cord.

 

[bmwhitetx]

The FCSP is big and bulky and because it has a CCS1 connector it will not charge your eventual Jeep without dremel tool surgery on a CCS1 adapter. So you would likely have to switch back to your original plan anyway.

I would go with your original plan.

 

[invertedspear]

Is it a 23 or 24 ER? The 24 will only charge up to 48 amps. 24 does NOT come with the FSCP. There are a lot of cheaper EVSEs available than the Ford charger.

23, I have the FCSP sitting in the garage catching dust.

 

[invertedspear]

I think the surviving parallel circuit would overheat quickly and start a fire, not certain the 100 amp breaker would intervene in time to prevent a catastrophe!

I was thinking I would keep them on the 50 AMP breakers, combining them in the cut-off box in the garage. Maybe electricity doesn't work like this?

 

[TaxmanHog]

I was thinking I would keep them on the 50 AMP breakers, combining them in the cut-off box in the garage. Maybe electricity doesn't work like this?

In that method of operation, in a partial failure scenario you would definitely blow the other 50-amp breaker as 75-80 amps of load tried to pass through it.

 

[Maquis]

No, you absolutely can’t do this. You would be essentially paralleling the branch circuit conductors. The NEC only allows paralleling conductors sized 1/0 or larger.
There are other more technical reasons why this won’t work (safely) as well.

 

[Runaway Tractor]

Yes it would work. And also it is a terrible thing to do. Pull the 4 gauge copper and do it right.

 

[invertedspear]

The breakers would still trip. In theory you could combine the two wires and put in a 100A breaker but doing that safely is probably more trouble than it is worth.

I don't see why buying an ER means that you need that much charging power, if you take a 100 mile trip in an ER it will take exactly (almost) as much energy to recharge as if you had taken a SR. I think your original plan of multiple chargers is best. At the moment I wish I had two, I just took an unexpected trip to Bellingham after a long trip so the Ford is low, and we left the EV6 at a low state of charge as recommended while we were gone and my wife needed to take a trip with it. Now I have two cars at a low state of charge. It is no big deal, they will both be charged by tomorrow but at some point I'm going to have to remember to go out and swap the cord.

I wouldn't be considering this if I wasn't having situations come up where my driving needs left me undercharged periodically. Multiple times coming in late and needing to leave early on the weekends. Currently taking 20 mins at a DCFC occasionally corrects for it, but charging at home is cheaper in the long run, as long as there isn't a bg cost like 120 feet of thick copper wires.

 

[invertedspear]

No, you absolutely can’t do this. You would be essentially paralleling the branch circuit conductors. The NEC only allows paralleling conductors sized 1/0 or larger.
There are other more technical reasons why this won’t work (safely) as well.

Appreciate this. I'll chalk this up as a dead end idea then. Not really caring what the NEC says, but more caring why, if you can give a layman's explanation, I would appreciate it.

 

[invertedspear]

Yes it would work. And also it is a terrible thing to do. Pull the 4 gauge copper and do it right.

So a dead-end idea, but do you mind adding any color on why it's a terrible idea?

 

[Runaway Tractor]

There is no way to actually control how much current flows on each conductor. You've doubled the terminations. Any issue can rapidly and drastically overload other leads.

 

[Tony Burgh]

Is it physically possible? Yes. Assuming you have two 50 amp circuits with 8 gauge wire of similar run length, the current pull of 80 amps should distribute by line resistance. The 50 amp circuit breakers optimally will be opposite each other or sequential in the panel so matching cycles will give you 120 volts and not 240 volts (disaster since closed circuit with no resistance - bang).
Yes, possible but dangerous and easily wired wrong. To say nothing about the poor sucker who buys or inherits this cludge from you.

Final analysis - don’t do it. I’m positive that no licensed electrician will install this.

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