Electrician wants to put in a Disconnect for the FCSP

[Maquis]

And to clarify for the OP, the #1 aluminum only goes from your panel to the line side of the disconnect. The copper is required for the terminals on the FCSP and must be used on the load side of the disconnect or the whole circuit.

Thanks, I should have been more complete.

Sponsored

 

[flyct]

So the electrician wanted to run aluminum from the main panel to the disconnect to help with the cost. What gauge wire should it be? Am I going to lose any charging capacity at the FCSP or have my house burn down from using aluminum on that long of a run with continuous amperage load to the disconnect? Will the the aluminum or disconnect slow down my charging?

You already likely have aluminum SER cable to the main panel from the grid. Aluminum properly sized should not be an issue to the disconnect. It will not slow down charging.

 

[Pioneer74]

And, this is just me, but I would install a fusable disconnect.

If/when you don't want to use the FCSP anymore, you can use the existing feed to the disconnect for any amperage EVSE. You can then size down the fuses for the amperage you need. Could help when installing a future NACS device. There aren't many 80 amp EVSE's on the market, or vehicles that need that capability.

 

[TaxmanHog]

I put a disconnect within reach of the EVSE just for safety's sake, the brand-new load center installed in my motorcycle shop is only 20 feet from the auto garage where the FCSP is mounted.

 

[Danface]

Can he use #1 Aluminum service wire to the sub panel and then #3 THHN copper for the hot and #6 THHN copper for the ground in conduit between the sub panel and charger?

 

[Maquis]

Can he use #1 Aluminum service wire to the sub panel and then #3 THHN copper for the hot and #6 THHN copper for the ground in conduit between the sub panel and charger?

Yes

 

[Maquis]

And, this is just me, but I would install a fusable disconnect.

If/when you don't want to use the FCSP anymore, you can use the existing feed to the disconnect for any amperage EVSE. You can then size down the fuses for the amperage you need. Could help when installing a future NACS device. There aren't many 80 amp EVSE's on the market, or vehicles that need that capability.

I installed a 100A Square-D 6/12 main lug panel with a 100A breaker for a disconnect. It costs less than a fused disconnect and will be very flexible for future changes.

 

[Danface]

Yes

Thanks, I'd bet that would be the most robust and less expensive way to go

 

[Larryumo]

I have a 125ft run of copper for the FCSP being ran. There is about 90ft to get to the attached garage and the rest to where the charger is being placed. Electrician says it’s a national electrical code to put in a disconnect on the entry into the garage because it’s going to be rated at 100amps. He said he could do that or a panel. Other electricians I have talked too said to go straight from the main panel to the charger, nothing in between. I told them I don’t need something in between that could fail but they are not budging. They said they will make sure it is pulling 80amps at the charger even with the disconnect there. Any opinions on what I should do? They have done this before and been successful.

Lightning (the sky type) likes underground cables. With a separate breaker in-between your house and the charge point you lessen (not eliminate) the chance of house entry of a strike.

 

[DiveMan911]

FWIW…the permit that was pulled for my FCSP install stated we needed to have a means of disconnect nearby the EVSE. It was explained to me that this was to provide a means of ensuring that branch circuit remained “off” if any work was being done on it, so someone didn’t inadvertently flip that breaker back on unknowingly.

My electrician wasn’t aware of this (altogether another story ).
He ended up providing a way to lockout the breaker…and that satisfied the inspector.
Here it is:
https://www.masterlock.com/products/product/493B

Mind you…I’m in Santa Barbara County, CA, and I don’t think they let much slide in code enforcement.
Just my 2 cents. There are plenty of people here with far more expertise than myself that are well versed in this (@Maquis comes to mind). Certainly worth asking your electrician if that would satisfy them.

 

[Larryumo]

Nope not at all, aluminum to the disconnect and copper to the charger since ford says no aluminum , probably more or less to cover themselves and possibly terminals not rated for aluminum expansion and contraction and the risk of loose terminals over time.

I have 2awg SE Aluminum to my disconnect and 2awg copper disconnect to charger . Wire is barely warm to touch even at 3 hours in on a 30-80 charge

Aluminum got a bad name in older homes but guaranteed your service drop is aluminum and will never be an issue.

When dealing with Aluminum, be sure to use Noalox.

 

[MaintGrl]

When dealing with Aluminum, be sure to use Noalox.

I second that!

 

[ddimit]

As soon as I read disconnect and aluminum, first thing I thought of was Tom's video. "Dangerous Disconnect: Tesla Home Charging Problem Analyzed And Corrected"

These disconnects are designed for AC units and not for 100% usage, invest in a knife-style lockable disconnect.

 

[tls]

I installed a 100A Square-D 6/12 main lug panel with a 100A breaker for a disconnect. It costs less than a fused disconnect and will be very flexible for future changes.

Only thing to be aware of for those considering this is that if you ever intend to use the panel for any 120V loads, you'll need one extra wire in the cable feeding it, for the neutral. The EVSE itself just needs two hots, no neutral. This will increase the cost of the cable itself but because 100A disconnects are so expensive, you'll probably still come out ahead.

Or mark the panel clearly "240V loads only - no neutral" and call it good. There is no code problem with this, but you could conceivably run into a grumpy inspector who tries to find or invent one.

 

[Amps]

mark the panel clearly "240V loads only - no neutral" and call it good

It is marked.

Sponsored