Tesla requires 60A Disconnect switch w/charger?

[Roman_O]

Congrats for answering 4 year old posts in a thread last replied to 2 years ago, and getting your facts wrong. A 240v circuit is made up of two 120v phases, which makes it less than 150v to ground.

You are right in BOTH sentences. I replied on old post because I found it the most relevant to my issue and I saw that people set $20 disconnect switches and after this surprised by seeing attached picture.
Regarding the 150V code requirement, you are absolutely right. I had a misguided haze when I wrote this.

 

[Roman_O]

As far as I know electrons are electrons whether they are in US or anywhere else.

We are limited to 32A of 240v on a single phase circuit. As I recall that's 7.6 kW out of the grid. I just wondered if there could be any problem or special considerations to be taken in setting it up.

If I understood correct, in US Tesla Wall Connecter uses split phase (115V each hot wire) and ground. Wall Connecter provides maximum 230V x 48 Amp = 11Kw = 14.8 HP. This is why Disconnect switch rated to 10HP is not correct solution and cause to that I showed in previous post.
If you installed $20 disconnect switch rated for 10HP, you should limit Wall Connecter for 31 Amp.

 

[davewill]

As far as I know electrons are electrons whether they are in US or anywhere else.

We are limited to 32A of 240v on a single phase circuit. As I recall that's 7.6 kW out of the grid. I just wondered if there could be any problem or special considerations to be taken in setting it up.

Yes, but laws are not the same and this whole thread is about U.S. code in regards to disconnects. Plus, you don't even say what you're trying to do. Plug in a mobile connector? Install a wall connector?

 

[QtownTaxiGreg]

I didn't know a plug in connector could even do 7.6kW if you had a wall outlet wired for it. A three pin 240v house plug is 10A here. You would need some extra hoofy wiring and plug and socket set. I think that's probably why I went for the hard wired version.

At that stage I had not clocked onto the fact these are only safety switching for the A/C home to car link. Someone was talking about the work the charger on board does and the penny dropped.

It's a brand new Gen3 wall connection. It could do 11kW with 3 phase but I would have to pay for a whole separate grid connection. 16 amps on each @ 240V.

So, as I recall, 32 amp breaker is the biggest allowed on single phase. I don't know if that is due to code or the wall unit. I was just wondering if anyone could see any gotchas in the hookup?

 

[Roman_O]

I didn't know a plug in connector could even do 7.6kW if you had a wall outlet wired for it. A three pin 240v house plug is 10A here. You would need some extra hoofy wiring and plug and socket set. I think that's probably why I went for the hard wired version.

At that stage I had not clocked onto the fact these are only safety switching for the A/C home to car link. Someone was talking about the work the charger on board does and the penny dropped.

It's a brand new Gen3 wall connection. It could do 11kW with 3 phase but I would have to pay for a whole separate grid connection. 16 amps on each @ 240V.

So, as I recall, 32 amp breaker is the biggest allowed on single phase. I don't know if that is due to code or the wall unit. I was just wondering if anyone could see any gotchas in the hookup?

In US we use one split phase 115V , 115V and ground. So Tesla Wall Connecter uses 230V. Breaker on both "hot" lines is 60Amp, but Wall Connecter uses 48Amp. As result disconnect switch should support 230 x 48 = 11 Kw =15HP

 

[QtownTaxiGreg]

In US we use one split phase 115V , 115V and ground. So Tesla Wall Connecter uses 230V. Breaker on both "hot" lines is 60Amp, but Wall Connecter uses 48Amp. As result disconnect switch should support 230 x 48 = 11 Kw =15HP

That's what is known here as 3 phase power I think. 2 hot and one ground. We limit the amps since our voltage is higher. End result same amount of power. 11kw as advertised. Twin 24 amp hot wires hot enough at 240v I guess, not too sure.

I am handicapped by only having a single phase, limited to 32A, of 240v available.

At least my power retailer responded positively and smartly today to my query about hooking up EV charging. I haven't been too happy with them and their haphazard comms when we have had problems with estimated reads being 5x consumption. So I contacted a few more highly rated suppliers who really didn't want to know about my backwoods internet and fitting a new meter.

All the metering around the country relies on either cellular data or ripple control for variable tariffs. We ain't got no cellular data here! All the CS people seem to completely fail to grasp that basic concept. It's highly frustrating.

Tell them over the phone. Tell them by email. They keep coming back to my meter is about to be upgraded to smart capable and hang tight. I got a car needs charging! Well, I do when they cave and give me the non leaky tail lights.

 

[NickFie]

HOWEVER... a 60A non-fusible disconnect costs $10 at most. It's what's used for every home air conditioner unit.

Fusible disconnects are incompatible with EV Supply Equipment (EVSE) such as Tesla Wall Connector. Installing one on an EVSE circuit creates a fire risk.

Non-fusible disconnects protect against sustained high current draw. All other home equipment only draws max current for short periods. AC compressor startup, ovens and dryers only heat part of the time.

EVSE is the first home appliance that draws high current for sustained-many hours-periods. This generates heat at new points along the circuit. It invalidates many “standard practices” (rule of thumb, this is the way we always do it…).

Electricians are still climbing the learning curve. This “State of Charge” video is a good example.

 

[Eric33432]

That's what is known here as 3 phase power I think. 2 hot and one ground. We limit the amps since our voltage is higher. End result same amount of power. 11kw as advertised. Twin 24 amp hot wires hot enough at 240v I guess, not too sure.

I am handicapped by only having a single phase, limited to 32A, of 240v available.

At least my power retailer responded positively and smartly today to my query about hooking up EV charging. I haven't been too happy with them and their haphazard comms when we have had problems with estimated reads being 5x consumption. So I contacted a few more highly rated suppliers who really didn't want to know about my backwoods internet and fitting a new meter.

All the metering around the country relies on either cellular data or ripple control for variable tariffs. We ain't got no cellular data here! All the CS people seem to completely fail to grasp that basic concept. It's highly frustrating.

Tell them over the phone. Tell them by email. They keep coming back to my meter is about to be upgraded to smart capable and hang tight. I got a car needs charging! Well, I do when they cave and give me the non leaky tail lights.

It is not three-phase power in the US. It is not two-phase power. It is split-phase power. Basically, it is the secondary of a single phase 240 volt transformer with a connection to the mid point of the secondary coil which is known as a center-tap. The center tap is grounded, giving 120 volts between the neutral and L1 or L2. L1-N-L2 gives 120-0-120.

In the US small appliances, lights, most electronics operates from 120 volts, and larger appliances like ovens, ranges, water heaters, central air conditioning, central electric heating, Level 2 electric car charging, operate from 240 volt power.

It is SINGLE PHASE. Even though L1 and L2 are out of phase with each other 180˚, it is NOT 2 phase power.

This article goes into more detail:

Split-phase electric power - Wikipedia

en.wikipedia.org

 

[QtownTaxiGreg]

Thanks. I am pretty sure we are just calling it the wrong thing. Even if not, and it really is true three phase, we don't get 480V worth of power out of it down the lines we use.

 

[Roman_O]

It is not three-phase power in the US. It is not two-phase power. It is split-phase power. Basically, it is the secondary of a single phase 240 volt transformer with a connection to the mid point of the secondary coil which is known as a center-tap. The center tap is grounded, giving 120 volts between the neutral and L1 or L2. L1-N-L2 gives 120-0-120.

In the US small appliances, lights, most electronics operates from 120 volts, and larger appliances like ovens, ranges, water heaters, central air conditioning, central electric heating, Level 2 electric car charging, operate from 240 volt power.

It is SINGLE PHASE. Even though L1 and L2 are out of phase with each other 180˚, it is NOT 2 phase power.

This article goes into more detail:

Split-phase electric power - Wikipedia

en.wikipedia.org

Unfortunately many local licensed electrician does not aware about it. They read US code requirement to install disconnect switch if "more than 150V from line to ground" as requirement to install disconnect switch before Tesla Wall Connecter, because it uses 240V. But actually it is two "hot" wires with only 120V to ground.

 

[appleguru]

Thanks. I am pretty sure we are just calling it the wrong thing. Even if not, and it really is true three phase, we don't get 480V worth of power out of it down the lines we use.

You're in NZ... NZ residential power is typically 3 phase. This is not the case in the US (where residential power is typically split-phase and commercial power is 3 phase.

In NZ, the average home has 230V 50Hz 3 phase power (230V Phase to N/G, 400V Phase to Phase)
In the US, the average home has 240V 60Hz, split phase power (120V phase to N/G, 240V "phase to phase")
In the US, some businesses have 480V 60Hz 3 phase power (277V phase to N/G, 480V phase to phase), though most also have 3 phase 208V (120V phase to N/G, 208V phase to phase).

None of this is really relevant to your question though.. just follow your local code, and the Tesla install instructions and you'll be fine.

https://www.tesla.com/en_NZ/support/charging/wall-connector

https://www.tesla.com/sites/default/files/support/charging/Gen3_WallConnector_Installation_Manual_AU_NZ.pdf

 

[QtownTaxiGreg]

My installer may not have done too many, if any. I just thought would keep abreast of things as is my way.

Everyone I speak to mentions another firm altogether to engage who are not on the Tesla list of two.

 

[SteelClouds]

You might be cheaper just to tell him to fuse it for 50amps and charge at 40amp

Exactly what I do and have done for the past 3 years.