Charge rate for non-standard power combinations

[aslam]

How do you have 347V at home?! That would be my first question...

and only 15A?

Quick 220 should help you to get 30A

@ytwytw Yeah I asked I'm about doing a Quick220 but there aren't any other circuits around that we can pull from. This is a cement underground parkade and I'm on P3 so unless I'm allowed to drill through the concrete (super expensive) the options are pretty limited.

 

[aslam]

347VAC is pretty common for commercial properties as it's a 3 phase system.
Quick 220 would only work if he could get two separate 120V circuits on different phases - could be difficult to find another 120V circuit nearby on a different phase.

@Doubled You're 100% correct. This is a standard commercial system. And I asked about getting two 120V circuits which would essentially give me the same thing (240V / 15A) but we don't have two circuits on different phases within easy vicinity of my parking stall.

 

[aslam]

Option 2 is definately what you'll want. Option 1 will charge too slow to be of any use. You'll see approx 240v @ 12A (which is 80% as mentioned by another member) = 2.88kW. On empty it will take approx 26h to charge your 75kWh battery.....


Where you park | Tesla

A Tesla Wall Connector installed on a 60 amp / 240 volt circuit breaker will achieve the maximum charge rate of 11.5 kW for 75 kWh configured vehicles. A Tesla Wall Connector installed on a 90 amp / 240 volt circuit breaker will achieve the maximum charge rate of 17.2 kW for a 100 kWh configured vehicle.

@shiny Yeah. Getting a wall connector on a 90 A / 240 V circuit is my dream but alas that will not happen without some serious drilling through concrete to get to the electrical room which is two floors up. That would cost too much, I think.

 

[aslam]

You are really testing the circuit if you haul down a 347 volt lighting line...
Why?
1. The lighting circuit will already be drawing up to 80% of it's rated load. If it's a 347 V 15 amp circuit, it has about 4160 watts available. If you pop in a 5 KVA - 347/240 transformer, and try to draw 12 amps at 240 volts (NEMA 6-15 plug), you will draw at least 2880 watts, plus losses in the transformer - leaving only 1280 watts maximum, for the lighting circuit.
2. I suspect that there may be some harmonics or electrical noise that kick off from a UMC. As it's not a dedicated circuit, the lighting power supply ( A ballast for fluorescent,HID or LED lights) may not work well, causing flickering, or cycling.
IF you can dedicate a 347 volt circuit it might be okay. Otherwise, I wouldn't consider it

@DMC-Orangeville You make some good points. I've asked the electrician to tell me what the likelihood is of me tripping the circuit. I will ask him to do a load test before choosing this option. I'll also ask him about the flickering. Alas my only other option is the 120V/15A which is definitely not going to be enough. The only reason why I was getting access to the 347V was because the lighting system was already at that. No way I can get a dedicated 347V for me.

I wonder if I could do a Quick 220 setup with the regular 120V/15A for one circuit and then draw the second circuit from the lighting system and down step from 347 down to 120. Any reason why that wouldn't work?

 

[aslam]

I guess no one else beat me to it.

I’m seeing up to 12 km/h of charge on 240V/12A (compared to 6 km/h on a 120V NEMA 5-15 plug).

@Scott_K Thanks for the test. 12 km/h is certainly a lot better than the 6 I will get from the 120V/15A one. Fingers crossed I can make it work.

 

[aslam]

This should help with your estimates...
View attachment 275663

@FlatSix911 Thanks for that chart. That matches up with what @cwave1 reported.

 

[aslam]

If your circuit is fused at 15A, you can use 80% of it.... so you can charge at 12A

Interesting. Does anyone know the reason why we can only use 80% of the circuit? What causes the loss of the 20%?

 

[Scott_K]

Interesting. Does anyone know the reason why we can only use 80% of the circuit? What causes the loss of the 20%?

It’s not so much that the 20% is being lost anywhere. It’s just a limitation put on continuous loads for safety reasons in the Canadian Electrical Code (Rule 8-104[5]).

Continuous Circuit Loading, Rule 8-104 | IAEI Magazine

 

[sakimano]

bear in mind that newer Canadian market cars have a Nema 14-50 adapter plug that limits the car to 32A

My 2015 70D had the older style that allowed the car to charge at 40A and about 48 km/hr

My P90D has the newer style that limits it to 32A unfortunately so I only get abou 34-35 km/hr

Keep that in mind when making your plans.

 

[aslam]

It’s not so much that the 20% is being lost anywhere. It’s just a limitation put on continuous loads for safety reasons in the Canadian Electrical Code (Rule 8-104[5]).

Continuous Circuit Loading, Rule 8-104 | IAEI Magazine

Thanks for that. Interesting reading. So much to learn about electricity and charging! I wish there was a good primer out there that covered all of this.

 

[aslam]

bear in mind that newer Canadian market cars have a Nema 14-50 adapter plug that limits the car to 32A

My 2015 70D had the older style that allowed the car to charge at 40A and about 48 km/hr

My P90D has the newer style that limits it to 32A unfortunately so I only get abou 34-35 km/hr

Keep that in mind when making your plans.

@sakimano Really??? Do you know why they did that?

 

[ShawnA]

I just bought a UMC Gen 1 for 14-50... Get them while you can...
It will charge the Model X at 40A not 32A with the UMC Gen 2 that comes with the car.
I am in USA.

Shawn

 

[wayner]

@sakimano Really??? Do you know why they did that?

I belive it is the electrical code. A couple of years ago they sent out new cables and asked us to return the old ones.

 

[aslam]

I just bought a UMC Gen 1 for 14-50... Get them while you can...
It will charge the Model X at 40A not 32A with the UMC Gen 2 that comes with the car.
I am in USA.

Shawn

@ShawnA Are you plugged into a 50A circuit or a 40A circuit? Because if it is pulling 100% of a 40A circuit, then I would think that is dangerous. However if it is pulling 80% of a 50A circuit, then that makes more sense and I will definitely buy one.

 

[ShawnA]

Hi Aslam,

It is plugged into a 50A circuit... which is 125% of the 40A load.

Shawn

 

[aslam]

Hi Aslam,

It is plugged into a 50A circuit... which is 125% of the 40A load.

Shawn

Ah, ok. That makes sense, then. Because if you use the 80% rule a 50A circuit will give 40A continuous without any problems. In that case, that's a good option and I will look into buying a Gen 1.

Interestingly, the electricians I've spoken to say they normally put in 40A circuits not 50A circuits. I wonder why that is.

 

[ShawnA]

Hi Aslam,

It sounds like bad practice. I am not an electrician.
I have read enough here that says for continuous use
a circuit should be equipped for 125% of the continuous load.
125% of 40A is 50A.
The reciprocal of 80% also works...
80% of 50A is 40A.
So, I think we are all saying the same thing - Except for the ones that say 40A circuit for 40A continuous load.

Remember too, I am US.
80% of 40A is 32A... I believe that is the solution recommended for Model 3.

Canada has unique rules that I am not aware of... So beware...

Shawn

 

[aslam]

Hi Aslam,

It sounds like bad practice. I am not an electrician.
I have read enough here that says for continuous use
a circuit should be equipped for 125% of the continuous load.
125% of 40A is 50A.
The reciprocal of 80% also works...
80% of 50A is 40A.
So, I think we are all saying the same thing - Except for the ones that say 40A circuit for 40A continuous load.

Remember too, I am US.
80% of 40A is 32A... I believe that is the solution recommended for Model 3.

Canada has unique rules that I am not aware of... So beware...

Shawn

Yeah we are saying the same thing, I believe. And so far everything you're saying is the same that my Canadian electricians are saying (can only have 80% of the rated capacity for continuous load). I think they are just saying the 80% whereas you're using the 125% inverse.

However I still wonder why they don't want to install 50A circuits and say they are more used to installing 40A circuits which, would only give me 32A usable.

 

[DMC-Orangeville]

Yeah we are saying the same thing, I believe. And so far everything you're saying is the same that my Canadian electricians are saying (can only have 80% of the rated capacity for continuous load). I think they are just saying the 80% whereas you're using the 125% inverse.

However I still wonder why they don't want to install 50A circuits and say they are more used to installing 40A circuits which, would only give me 32A usable.

They should be installing a 50 amp circuit regardless. There are many threads about this. Below are some posts I made on my discussions with ESA. The discussion was about the de-rating of the 14-50 UMC adapter in Ontario. I asked a head inspector for reference, and he came back with a 14-50 should be on a 50 amp circuit - because someone may plug 40 amps into it.....

My posts:
Link 1: Beginning of thread where new UMC and 14-50 adapter was sent to everyone in Ontario: New UMC?
Link 2: Later in this thread....New UMC?
Link 3: the response I received from The Ontario ESA:New UMC?

 

[yuhong]

The fun thing is that even most DCFC chargers are 277/480V. Of course, I don't know which kind of circuit KSI installed their chargers on, but note that DCFC charging don't end at 50kW.