Does house main have to be shutoff for TWC install?

[JustABill]

I was planning on having a 60A breaker added to breaker box and new conduit + wiring from breaker box to TWC. An electrician told me they wouldn't have to shut off my house power at all during the install. Does this sound right? Wouldn't they have to shut off the house main to avoid working on hot wires?

I'm just trying to make sure I understand the process.

Thank you!

 

[rwiegand]

No need to shut the power off. The only thing close to hot work is snapping the breaker in place at the end (they won't electrify the new circuit until the very end of the installation). Even so, electricians work safely on live wires all the time.

If you were going to DIY it then I'd tell you yes, absolutely, turn the power off.

 

[Tronguy]

The Gen 2 required that the breaker be off at the panel when all the wires get connected and the mechanical switches get set. A friend bought a M3, had an electrician do the install, and the idiot electrician (not a Tesla-certified type) flipped switches with the power on. Then beat feet out of town before my friend found out. The circuit board was fried.

Luckily, the on-line Tesla service rep declared the Wall Connector as being DOA and drop-shipped him a new one. This, my friend installed, following the directions this time, and it all worked.

Current version is Gen 3 which doesn’t have mechanical switches. Manual, which is on-line, will say. But as a EE, throwing arcs and sparks around when wiring up electronics is a no-no. But you don’t generally need the mains turned off, just the breaker attached to the WC. Unless you just don’t like working inside an energized breaker panel.

 

[ScottNY]

I used a licensed electrician straight from Tesla’s list of certified installers. He put in a 60 amp breaker, ran conduit and wire, and hooked up the Wall Connector. I have 60 amps at ~240v going to the WC, and he never shut off main breaker to the house.

 

[VegasMYP]

I used a licensed electrician straight from Tesla’s list of certified installers. He put in a 60 amp breaker, ran conduit and wire, and hooked up the Wall Connector. I have 60 amps at ~240v going to the WC, and he never shut off main breaker to the house.

Same

 

[JustABill]

Thanks everyone! I guess the key is that the new 60A breaker just gets snapped in. It's not like someones stripping off some insulation on a wire then screwing that onto a post.

 

[ucmndd]

Thanks everyone! I guess the key is that the new 60A breaker just gets snapped in. It's not like someones stripping off some insulation on a wire then screwing that onto a post.

Most pros I see will clamp down the wires on the breaker first, then seat it on the bus bar. No need to shut off the mains. As an amateur hack I always do though because I've done the 60hz shuffle enough to not want to do it again.

 

[Plood]

There's lot of hot metal in the open panel, but adding a breaker to a hot panel is about like plugging in a lamp into a hot receptacle. It's designed to do that

 

[Rocky_H]

Thanks everyone! I guess the key is that the new 60A breaker just gets snapped in. It's not like someones stripping off some insulation on a wire then screwing that onto a post.

Well, that is exactly what's being done, but it's to the non-hot wires that go out to the wall connector that are still disconnected at that time. That is being manipulated and then inserted and screwed in to the breaker that you're holding in your hand that is NOT plugged into the panel yet. When the wires are set into the breaker, it's only then that you carefully press the breaker into the slot in the panel.

The other part to be careful of is attaching the ground or neutral wires onto those bars in the open panel. The ground and neutral are at 0V, so they are not dangerous, but you don't want to accidentally have a hand or screwdriver slip and hit one of the hot lines that the breakers snap onto.

 

[MacO512]

Leave working in hot panels to licensed electricians. It's not a general DIY project that can be done safely.

The smallest breakers are 15 or 20 amps. Less than 1 amp can kill, so breakers don't provide safety to people, they provide some protection to wiring in the house and devices.

Anyone working in a hot panel should know very confidently what they're doing and wear proper protection. Eye protection as if something arcs it could send molten metal flying, plus wires can be razor sharp and unexpectedly hit your face. Gloves just so you don't have bare wet skin potentially touching something, insulated shoes, and insulated tools.

 

[JustABill]

Thank you. I'm not going to attempt any of this work myself. I just wanted to make sure that this sort of work is reasonable for licensed electricians to do.