Welcome to Tesla Motors Club
Discuss Tesla's Model S, Model 3, Model X, Model Y, Cybertruck, Roadster and More.
Register
  • We just completed a significant update, but we still have some fixes and adjustments to make, so please bear with us for the time being. Cheers!

Powerwall Automated Load Shedding?

aesculus

Still Trying to Figure This All Out
May 31, 2015
4,301
2,460
Northern California
I was thinking running control circuitry based on the low voltage relay that already controls the HVAC load shedding. Its a normally closed relay that opens when the grid goes out, if you have it set that way in the app.
Can you be more specific on what you are referring to? Which App and which relay?

BTW I don't want a system that requires a internet connection. I want everything local.
 

Vines

Active Member
Jul 20, 2018
1,783
2,062
Silicon Valley, CA
Can you be more specific on what you are referring to? Which App and which relay?

BTW I don't want a system that requires a internet connection. I want everything local.

The Tesla Powerwall App has load shedding built into it. Whether its currently working I am honestly not sure. I have heard both it working and not working.

Inside the App there is a slider that asks whether to load shed the HVAC. Setting this to on causes a DC relay inside the GW to stay open during grid out events. I was imagining you used a NO DC contactor of whatever size to keep the AC circuit to be shed closed as long as there is grid power, and when grid goes out the objectionable load turns off automatically.
 
Last edited:

RKCRLR

Member
Apr 13, 2020
250
101
Garden Valley, CA
The Tesla Powerwall App has load shedding built into it. Whether its currently working I am honestly not sure. I have heard both it working and not working.

Inside the App there is a slider that asks whether to load shed the HVAC. Setting this to on causes a DC relay inside the GW to stay open during grid out events. I was imagining you used a NO DC contactor of whatever size to keep the AC circuit to be shed closed as long as there is grid power, and when grid goes out the objectionable load turns off automatically.
I agreed to a whole house backup system but it turns out my HVAC is not compatible with SureStart. I've asked Tesla what they are going to do about it. They've alluded that they're considering a load shedding relay but haven't been able to give me any details about how it would work.
 

aesculus

Still Trying to Figure This All Out
May 31, 2015
4,301
2,460
Northern California
Inside the App there is a slider that asks whether to load shed the HVAC. Setting this to on causes a DC relay inside the GW to stay open during grid out events. I was imagining you used a NO DC contactor of whatever size to keep the AC circuit to be shed closed as long as there is grid power, and when grid goes out the objectionable load turns off automatically.
Where is this option? I cannot find it in the app.
 

aesculus

Still Trying to Figure This All Out
May 31, 2015
4,301
2,460
Northern California
I am 99% sure this won't work in my environment. I have a bunch of PLC devices (Insteon) and another PLC device that I used to measure the power feed and they consistently fail reliable communications.

PLC is just not reliable enough for me.

On a side note I did notice Eaton has REST communicating breakers but you have to subscribe to their restful service (ie internet) and they also only seem to deal with large scale organizations.
 
  • Helpful
Reactions: mspohr

Vines

Active Member
Jul 20, 2018
1,783
2,062
Silicon Valley, CA
Where is this option? I cannot find it in the app.

I apologize I was wrong.

This is not a setting in the App, its in the commissioning wizard. We typically install Powerwall systems large enough to keep the HVAC on backup, so haven't set it up yet.

Tesla announced the feature last year in April, so there is firmware that works with it.

Load shed terminals are 3 and 4 on the 5 pin connector, this has a 60vdc 2A relay built in.

In the commissioning wizard select "Open relay when off grid" from the "Gateway Low Voltage Relay" option.
 
  • Informative
Reactions: aesculus

aesculus

Still Trying to Figure This All Out
May 31, 2015
4,301
2,460
Northern California
I apologize I was wrong.

This is not a setting in the App, its in the commissioning wizard. We typically install Powerwall systems large enough to keep the HVAC on backup, so haven't set it up yet.

Tesla announced the feature last year in April, so there is firmware that works with it.

Load shed terminals are 3 and 4 on the 5 pin connector, this has a 60vdc 2A relay built in.

In the commissioning wizard select "Open relay when off grid" from the "Gateway Low Voltage Relay" option.
I saved this info and will definitely probably use it on the PW side if Tesla does not come up with something holistic in the next 12 months.

Cutting off a signal wire from the thermostats is fairly easy as a means to keep the units from powering up. The hot tub on the other hand might be a bit more problematic. My hot tub is ancient and I am not sure how easy it would be to do something on the control board. Simpler to just cut it's power.
 

About Us

Formed in 2006, Tesla Motors Club (TMC) was the first independent online Tesla community. Today it remains the largest and most dynamic community of Tesla enthusiasts. Learn more.

Do you value your experience at TMC? Consider becoming a Supporting Member of Tesla Motors Club. As a thank you for your contribution, you'll get nearly no ads in the Community and Groups sections. Additional perks are available depending on the level of contribution. Please visit the Account Upgrades page for more details.


SUPPORT TMC
Top