What's up with HPWC?

[CmdrThor]

My X will draw 48 A max so I would dial down the HPWC as a remedy. Wouldn't just that work out fine if the HPWC is not drawing large amperage..

Dialing down the Wall Connector is good, but your 100A breaker is worthless because it will not stop your wire from catching on fire if somehow the Wall Connector draws too much current.

 

[ssq]

Dialing down the Wall Connector is good, but your 100A breaker is worthless because it will not stop your wire from catching on fire if somehow the Wall Connector draws too much current.

follow up question - assuming the HPWC dial is set at 48A and I never change it, I don't foresee any possibility of a catastrophic failure with the current setup. i.e I don't foresee a scenario wherein the THNN #4 will be subject to more than 48Amps. Or am I getting it wrong, is it the case that the HPWC is a step-down transformer or a similar circuit which can still draw > 80A while the output side is still at 48A? Help me understand please, thanks!

 

[Lloyd]

Youre getting it wrong. The breaker is there to protect the circut against over current. Suppose there is a failure or short in the wiring or in the HPWC. The breaker is not then sized properly to protect you against the failure of the circut . A fire could result.

 

[ssq]

Youre getting it wrong. The breaker is there to protect the circut against over current. Suppose there is a failure or short in the wiring or in the HPWC. The breaker is not then sized properly to protect you against the failure of the circut . A fire could result.

Thanks for clarifying, what would have been the right wire type for this HPWC install? I want to educate myself a bit more. I have read about THNN #4 so far. I believe that THNN #4 is well suited for a 100A subpanel sourcing per NEC code (non-sustained/continuous load) and it should be so even if a NEMA15-40 is put on that subpanel with a 50A breaker, yes? Confirming if at least that part of the circuit is in code compliance.

 

[Lloyd]

Thanks for clarifying, what would have been the right wire type for this HPWC install? I want to educate myself a bit more. I have read about THNN #4 so far. I believe that THNN #4 is well suited for a 100A subpanel sourcing per NEC code (non-sustained/continuous load) and it should be so even if a NEMA15-40 is put on that subpanel with a 50A breaker, yes? Confirming if at least that part of the circuit is in code compliance.

The minimum wire size for a 100 amp continuous circut is #3. I believe it states that in the installation manual for the HPWC. Since it is harder to find and more expensive, some elect to use #2 wire. Below is a wire ampacity chart for your reference.

Ampacity Charts

 

[FlatSix911]

follow up question - assuming the HPWC dial is set at 48A and I never change it, I don't foresee any possibility of a catastrophic failure with the current setup. i.e I don't foresee a scenario wherein the THNN #4 will be subject to more than 48Amps. Or am I getting it wrong, is it the case that the HPWC is a step-down transformer or a similar circuit which can still draw > 80A while the output side is still at 48A? Help me understand please, thanks!

You don't need to rewire... THNN #4 wire is fine for a single onboard charger.
Just set the rotary dial on the HPWC to 48A and change the circuit breaker to 60A.

 

[ssq]

You don't need to rewire... THNN #4 wire is fine for a single onboard charger.
Just set the rotary dial on the HPWC to 48A and change the circuit breaker to 60A.

View attachment 182063

thought so but please see posts #381-384 above. I will do that regardless.

 

[davewill]

thought so but please see posts #381-384 above. I will do that regardless.

He's telling you to do exactly what those other posts did, change both the setting on the HPWC and the circuit breaker.

 

[ssq]

He's telling you to do exactly what those other posts did, change both the setting on the HPWC and the circuit breaker.

I missed the 60A breaker part, I need more coffee..

 

[jason1466]

From the new HPWC manual I see "Daisy Chaining Multiple Wall Connectors"
Set one Wall Connector as the master by
setting the Rotary Switch Position from 1
to 8 depending on the maximum available
output current. Set up to 3 Wall
Connectors as slaves by setting the Rotary
Switch Positions to F. In the load sharing
network, only one unit can be designated
as the master (refer to Set the Operating
Current on page 21).

My 200A service panel has plenty of load capacity, so it seems I can use a 100A circuit to daisy chain 2 HPWC's I have on hand to install. However, the manual seems to say the Max charge setting in this instance is Setting # 8 = 40A. Is this just a typo? What good is daisy chaining if it just splits the 100A circuit in this case and limits my charge even when only one is in use.

 

[CmdrThor]

From the new HPWC manual I see "Daisy Chaining Multiple Wall Connectors"
Set one Wall Connector as the master by
setting the Rotary Switch Position from 1
to 8 depending on the maximum available
output current. Set up to 3 Wall
Connectors as slaves by setting the Rotary
Switch Positions to F. In the load sharing
network, only one unit can be designated
as the master (refer to Set the Operating
Current on page 21).

My 200A service panel has plenty of load capacity, so it seems I can use a 100A circuit to daisy chain 2 HPWC's I have on hand to install. However, the manual seems to say the Max charge setting in this instance is Setting # 8 = 40A. Is this just a typo? What good is daisy chaining if it just splits the 100A circuit in this case and limits my charge even when only one is in use.

I say yes a typo because someone up thread already installed two Wall Connectors with the master on a 100A breaker (rotary switch set to D) and the slave would have the rotary set to F. Maybe they originally weren't planning on having as many breaker settings.

 

[aesculus]

Is this just a typo?

Up thread it was confirmed as a typo.

 

[SMSMD]

My Wall Connector is all set thanks to @FlasherZ and all other. .used a Tech 90 #2AWG, 2 conductors and one ground which is a flexible metal, fire and water resistant cable, Passed Inspection, waiting for delivery of my X this week

 

[aesculus]

You know that plastic hose rest is redundant. The new WC is designed to allow you to loop the cable over the top. I have one of those Gecko hose clips at the bottom just to keep it all neat.

 

[masam]

For those that ordered the HPWC online - did it actually take 3-4 weeks to arrive ?
Thanks!

 

[Tech_Guy]

If your local to a service center id suggest calling to see if they have one in stock was able to get mine same day...

 

[goneskiian]

For those that ordered the HPWC online - did it actually take 3-4 weeks to arrive ?
Thanks!

Nope.

 

[cmd_keen]

Btw, I have an extra brand new HPWC (new 80A model with the charge handle holder on the side)... $450 shipped anyone interested?

Oh, btw it's the 8.5' cable length.

Tesla — Wall Connector with 8.5' Cable

 

[djgabriel2004]

Hi I'm interested

 

[TechVP]

This is what I settled on for my installation. I have 1/0 for 30 feet from my main panel with a 125 amp breaker to a sub panel. On the subpanel I have a 100 amp breaker on #2 copper to the WC set to 80 amps. I also have a 50 amp breaker on standby mode using #6 copper for a NEMA 14-50. I am using on of those Gecko hose holders to keep the bottom cables in place. Normally I don't even secure the last two loops but just drape them over the charger so it's easier to deploy and store.

View attachment 180667

Hi @aesculus

I'm planning for an install this coming week... and had sketched it out.
When I read your post & photo -- its nearly exactly what you completed. Luckily I came by your post.
I'm going to be 33' on from the main panel to a 125 amp subpanel. I will feed it with THHN 1/0. I just happen to have 2 CU segments just the right length handy. But I need to look up what gauge to use for ground?

Q1: What AWG is your ground line?
Q2: Is that the Eaton 6 space 12 circuit Subpanel?
Q3: Anything you would/should have done differently?

Thanks