Gen 3 Charger Power Sharing - who has this working?

[RudeDude]

Hopefully someone is willing to document a re-commission of their units or new setup so we can have a little more clarity. I'll make sure to do it once I get another WC

Not sure when I'll have time to do it... but I might do it and try to document for you and the community. I'd like to know for sure what the slave is set to and tempted to play with upping the total shared amps. The cabling has been very safe temps so far whether I pull max with the Model-Y or max across both cars so I'm feeling good about my branch wiring.

By the way... I used a thing called a "split bolt" to build my junction box for this branch sharing. https://www.amazon.com/dp/B0B3LBGC8N?psc=1&ref=ppx_yo2ov_dt_b_product_details So, I've got one set of wires (L1, L2, G) coming into junction and then the two coming out for the two TWCs. In my electrical research I learned that there are not wire nuts rated for three strands of 6 awg copper and a split-bolt (a compression splice) is the right way. Then you have to wrap the bolt and exposed ends with enough electrical tape / rubber tape to provide required insulation for 240v.

 

[brkaus]

By the way... I used a thing called a "split bolt" to build my junction box for this branch sharing. https://www.amazon.com/dp/B0B3LBGC8N?psc=1&ref=ppx_yo2ov_dt_b_product_details So, I've got one set of wires (L1, L2, G) coming into junction and then the two coming out for the two TWCs. In my electrical research I learned that there are not wire nuts rated for three strands of 6 awg copper and a split-bolt (a compression splice) is the right way. Then you have to wrap the bolt and exposed ends with enough electrical tape / rubber tape to provide required insulation for 240v.

Alternative is a Polaris connector

 

[RudeDude]

Alternative is a Polaris connector

I saw those briefly in my searching but the ports weren't always connected to each other, were kind of expensive, and were aluminum but my cables are copper... wasn't sure about the load passing through it.

 

[RudeDude]

Hopefully someone is willing to document a re-commission of their units or new setup so we can have a little more clarity. I'll make sure to do it once I get another WC

I didn't do a full re-commision (yet) but I took a couple screenshots that I don't think are shown very nicely in the docs. One shows the view where you would set the total amps for the shared circuit. The other is the "main" sharing page that shows my units' current status.

 

[rwojo]

I didn't do a full re-commision (yet) but I took a couple screenshots that I don't think are shown very nicely in the docs. One shows the view where you would set the total amps for the shared circuit. The other is the "main" sharing page that shows my units' current status.

Nice!

What type of circuit do you have? If similar to my upcoming situation, you could squeeze out a little more. For example, I was going to set my network to 52A (which is 80% of 65A calculated for 6/2 MC @ 75C) for the network for example.

Not sure what happens if two cars are connected and one is full. 52A - 6A is an weird 46A (not 48A). Will it do 6+40? 6+46? ¯\_(ツ)_/¯

 

[rwojo]

I saw those briefly in my searching but the ports weren't always connected to each other, were kind of expensive, and were aluminum but my cables are copper... wasn't sure about the load passing through it.

Oh it's totally capable of that and way more. But that option you had is much much cheaper and should be fine, just a little more DIY.

 

[RudeDude]

Nice!

What type of circuit do you have? If similar to my upcoming situation, you could squeeze out a little more. For example, I was going to set my network to 52A (which is 80% of 65A calculated for 6/2 MC @ 75C) for the network for example.

Not sure what happens if two cars are connected and one is full. 52A - 6A is an weird 46A (not 48A). Will it do 6+40? 6+46? ¯\_(ツ)_/¯

The breaker was originally a 50A for the NEMA-14-50 receptacle and I replaced that with a 60A. I wouldn't want to push my luck on the cabling getting hot in the summer on long charges. Maybe I'll get my IR heat sensor out this summer and see what temps I'm dealing with but the electrical code puts limits on the continuous draw with Copper AWG limits for a reason.

 

[holeydonut]

That is interesting. I read that you can set each unit, e.g. a slave unit matching the breaker it is on. Example:

Network: 48A
Master: 48A
Slave: 40A
Slave: 48A

In that case you'd have to set the slave units individually to match the breaker in the sub-panel.

Not going to matter for me since I'm planning on splitting a single branch so all units will be at the same max amperage.

The Tesla documentation says over and over that multiple Gen 3 EVSE's need to be on their own branch circuits with their own conductors and breakers. Daisy-chaining them seems to violate the install guidelines even if you used one of these Polaris things for #6 THHN.

I just installed a second Gen 3 TWC and the settings that RudeDude showed seem pretty straightforward.

Yes you can set the slave unit to be on a different maximum amperage. Fore example if the master is 48A, the slave can be 32A. And if you set the site maximum to be 64A, it should max out both at 32A if they were charging at the same time.

The only glitch I found was that if you set the site maximum to 0A, but each EVSE has a maximum of 48A, neither will charge even if there was only one vehicle plugged in. For some reason the 0A site limit was overriding the individual limits even if only one EV was charging. But if I set the site limit to like 24A, it would only throttle down each of the two EVSE's to 12A if they were both charging at the same time. If only one EVSE was active, it went back to 48A.

 

[Rocky_H]

The only glitch I found was that if you set the site maximum to 0A, but each EVSE has a maximum of 48A, neither will charge even if there was only one vehicle plugged in.

The only...glitch? That's exactly what it's supposed to do. That's what that setting is.

For some reason the 0A site limit was overriding the individual limits

The reason is that's what the setting is supposed to do. The definition of that setting is that all of the currents from the individual wall connectors added together cannot be over that total limit. If you set the total limit to 0, none of them can go above 0. That is operating how it is supposed to and honoring all of the proper limits.

 

[holeydonut]

The only...glitch? That's exactly what it's supposed to do. That's what that setting is.

The reason is that's what the setting is supposed to do. The definition of that setting is that all of the currents from the individual wall connectors added together cannot be over that total limit. If you set the total limit to 0, none of them can go above 0. That is operating how it is supposed to and honoring all of the proper limits.

Yeah but when I set the site limit to 24A (but only one car was plugged in), the sharing ruleset wasn't applied and the one EVSE went up to the individually configured 48A.

Aside from 0A, the site limit seems to only be applied when 2 of the EVSE's are pushing out suds.

 

[mongo]

Yeah but when I set the site limit to 24A (but only one car was plugged in), the sharing ruleset wasn't applied and the one EVSE went up to the individually configured 48A.

Aside from 0A, the site limit seems to only be applied when 2 of the EVSE's are pushing out suds.

Makes sense if 0 is used as a disable flag and one expects individual WCs to be set to what they can supply on their own. Seems like the global value should override regardless of number in use though.

 

[Rocky_H]

Yeah but when I set the site limit to 24A (but only one car was plugged in), the sharing ruleset wasn't applied and the one EVSE went up to the individually configured 48A.

OK, then that case would be a glitch where it is not honoring the limit. When it's set for 0 and everything is capped at 0 is operating correctly.

 

[h2ofun]

I am in the process of install 5 gen 3;s. I have not looked at the sharing details yet, but was hoping to put the panel source at like 120 amps, even though a 200 amp service. Each of the Gen 3's, have their own 60 amp feed to the breaker. Will this work? This would seem to allow me to charge 2 EV's at the max 48 amps. Then I am assuming if more are plugged in, it has the smarts to throttle back stuff?

 

[brkaus]

I am in the process of install 5 gen 3;s. I have not looked at the sharing details yet, but was hoping to put the panel source at like 120 amps, even though a 200 amp service. Each of the Gen 3's, have their own 60 amp feed to the breaker. Will this work? This would seem to allow me to charge 2 EV's at the max 48 amps. Then I am assuming if more are plugged in, it has the smarts to throttle back stuff?

I believe a max of 4 are supported in the balancing/sharing configuration.

 

[Sophias_dad]

I believe a max of 4 are supported in the balancing/sharing configuration.

According to a manual(maybe not the latest) the limit is 16.

 

[tm1v2]

@brkaus I think gen2 WC power sharing had a lower # of units limit, that might be where you're remembering "4" from.

 

[brkaus]

According to a manual(maybe not the latest) the limit is 16.

Yes. But the manual said that before there was even any support for sharing. I may be remembering incorrectly.

I do have gen2 at home. But I thought that was what I read here about gen3 (I’ve been considering upgrading).

 

[Sophias_dad]

Yes. But the manual said that before there was even any support for sharing. I may be remembering incorrectly.

I do have gen2 at home. But I thought that was what I read here about gen3 (I’ve been considering upgrading).

The current website says the maximum is six. Gotta say sixteen seemed kinda nuts.

 

[h2ofun]

I believe a max of 4 are supported in the balancing/sharing configuration.

doc says 6 now

 

[h2ofun]

The current website says the maximum is six. Gotta say sixteen seemed kinda nuts.

Going to try 5