Multiple HPWC Issues with Model 3

[NewTMSMan]

Does anyone have more than one HPWC installed and have them interconnected and are charging a Model X or S at the same time as the Model 3?

I have a 100A circuit for the HPWCs and they are interconnected and I have no issues charging my Model S and X at the same time. Lately when I charge the Model S and the Model 3 at the same time the circuit trips. Wondering if there is some issue with the Model 3 and using multiple HPWCs or if I have an issue with my chargers?

 

[araxara]

Does anyone have more than one HPWC installed and have them interconnected and are charging a Model X or S at the same time as the Model 3?

I have a 100A circuit for the HPWCs and they are interconnected and I have no issues charging my Model S and X at the same time. Lately when I charge the Model S and the Model 3 at the same time the circuit trips. Wondering if there is some issue with the Model 3 and using multiple HPWCs or if I have an issue with my chargers?

I have this exact configuration (Model S, Model X & Model 3 with 3 power sharing HPWC with 3-100amp breakers - in a 125A panel)

I have never had any circuit trips. Of course, I have 3 circuit breakers rather than one. Are you sure you have the proper interconnect between chargers? Only the master charger is set to 80A. The rest are set to Slave and the signal cable comes from the OUT of the master charger into the IN of the first slave. Then the signal goes from 1st slave OUT to 2nd slave IN.

If you could observe the current usage when the Model S and Model 3 are charging, you can see if there is too much current draw. What is the max your Model S can take? Mine can take 80A.

One thing I may do different than you is that I have staggered the changing times of each car, due to Time-of-use, although due to how much the cars get driven and plugged in, they may be charging at the same time.

 

[PhaseWhite]

Does anyone have more than one HPWC installed and have them interconnected and are charging a Model X or S at the same time as the Model 3?

I have a 100A circuit for the HPWCs and they are interconnected and I have no issues charging my Model S and X at the same time. Lately when I charge the Model S and the Model 3 at the same time the circuit trips. Wondering if there is some issue with the Model 3 and using multiple HPWCs or if I have an issue with my chargers?

I have 2 HPWCs on a 60Amp circuit connected together and I have not seen this issue. Though I have a different issue: When both chargers are plugged into the cars then but I want to only charge 1 car , that car gets only half the charging power (6KW) instead of the full 12KW that should be available when it's the only car charging. Unplugging the other car from the HPWC allows full current. I'm expecting it to be smart enough to know if both cars are actually charging or not but suspect there could be an issue with the charge port communication and the software updates optimizing charge port locking during winter time.

 

[ewoodrick]

I have this exact configuration (Model S, Model X & Model 3 with 3 power sharing HPWC with 3-100amp breakers - in a 125A panel)

I have never had any circuit trips. Of course, I have 3 circuit breakers rather than one. Are you sure you have the proper interconnect between chargers? Only the master charger is set to 80A. The rest are set to Slave and the signal cable comes from the OUT of the master charger into the IN of the first slave. Then the signal goes from 1st slave OUT to 2nd slave IN.

If you could observe the current usage when the Model S and Model 3 are charging, you can see if there is too much current draw. What is the max your Model S can take? Mine can take 80A.

One thing I may do different than you is that I have staggered the changing times of each car, due to Time-of-use, although due to how much the cars get driven and plugged in, they may be charging at the same time.

I don't believe that it is the same config as yours. The original poster seemed to have a single breaker for two chargers. You seem to have 3 chargers, each with their own breaker. I certainly hope that yours never trips. Actually having 100A breakers on each car wouldn't be my recommendation, I'd change to 60A, so if there was a problem, it would actually trip.

 

[NewTMSMan]

I am sure the HPWCs are wired correctly. Have had them a year and have been charging the S and X at the same time many times over the year.

The S can draw 72A, but is reduced to 40A when the 3 is connected. The 3 was drawing about 40A at that time as well.

May be a breaker going bad.

 

[sammyfan711]

I've had a breaker trip in the summer when the garage was hot and my X and S were sharing for several hours (at 40 amps each) and once when the 3 and S were sharing but never consistently the way you are describing.

 

[araxara]

I don't believe that it is the same config as yours. The original poster seemed to have a single breaker for two chargers. You seem to have 3 chargers, each with their own breaker. I certainly hope that yours never trips. Actually having 100A breakers on each car wouldn't be my recommendation, I'd change to 60A, so if there was a problem, it would actually trip.

The 3-100A breakers are for historical reasons. In the past I had 2 of the old style HPWC that did not share power each wired separately. At any time it could draw 80A+72A for two cars and would trip the 125A panel breaker. That's when I staggered the charging and quickly ordered the new style chargers. Later when I got the Model 3, my electrician recommended just putting it on it's own circuit.

But I don't understand why I would only charge at 60A.

 

[boaterva]

I have two on one 100 amp breaker, no issues. I do have both cars set to max charge at 40 amps since there is no reason they would need more. Thus I’ve never run up against the auto-sharing limits perhaps?

Wonder if that’s something?

 

[boaterva]

I have 2 HPWCs on a 60Amp circuit connected together and I have not seen this issue. Though I have a different issue: When both chargers are plugged into the cars then but I want to only charge 1 car , that car gets only half the charging power (6KW) instead of the full 12KW that should be available when it's the only car charging. Unplugging the other car from the HPWC allows full current. I'm expecting it to be smart enough to know if both cars are actually charging or not but suspect there could be an issue with the charge port communication and the software updates optimizing charge port locking during winter time.

Are you sure the HPWCs are set to master and slave and wired properly with the serial wiring between them? You do need to do that and not just ‘parallel’ them on one circuit, of course.

Manual, see at the end for wiring:

https://www.tesla.com/sites/default...nstallation_manual_80A_en_US.pdf?201612081439

 

[eSpiritIV]

Are you sure the HPWCs are set to master and slave and wired properly with the serial wiring between them? You do need to do that and not just ‘parallel’ them on one circuit, of course.

Manual, see at the end for wiring:

https://www.tesla.com/sites/default...nstallation_manual_80A_en_US.pdf?201612081439

This would be my guess as well.

Also, if you installed the wrong wire for a 100A circuit (even electricians do it wrong many times using 90 degree column vs 75 deg) The wire could be finally overheating enough to be causing trips.

3rd, yes a bad breaker also if it was not new when installed with the charger.

 

[animorph]

We have an X and a 3 charged with two HPWC's sharing one 100A circuit.

I haven't had any breaker trips, though I'm not sure we've had both chargers maxed out due to staggered charge times. 2x40A would max out the HPWC so if the breaker was going to trip that would do it.

We get the same 40A to one car if both are plugged in, even if the other car is not actively charging.

Charging was interrupted on the 3 a night ago. I restarted it in the morning, using just the app, and it charged fine. That's the only time in about three months that anything unusual has happened. The interrupted charge was not long enough to register on TeslaFi, so not much to troubleshoot with.

 

[boaterva]

We have an X and a 3 charged with two HPWC's sharing one 100A circuit.

I haven't had any breaker trips, though I'm not sure we've had both chargers maxed out due to staggered charge times. 2x40A would max out the HPWC so if the breaker was going to trip that would do it.

We get the same 40A to one car if both are plugged in, even if the other car is not actively charging.

Charging was interrupted on the 3 a night ago. I restarted it in the morning, using just the app, and it charged fine. That's the only time in about three months that anything unusual has happened. The interrupted charge was not long enough to register on TeslaFi, so not much to troubleshoot with.

It’s a 100 amp circuit. You are using a max of 80 amp. It’s really physically impossible to overload it and trip the breaker if the multiple HPWCs are wired TO EACH OTHER properly as the manual states. They communicate over serial cabling to tell each other how much each one is using and how much the other can use so the max is still (here) 80 amps.

If your electrician didn’t read the manual and do all this then it needs to be done. We’ve been talking about this for years, it’s really not rocket science. Also see Flasher’s excellent FAQ in my sig for more than you need to know for a normal installation.