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HVAC contractor or TESLA better to install sure start?

Hi, getting ready to install 11.3kw solar roof with 3 pws. Before that, installing a new HVAC, with a 135 LRA compressor (old one was was higher and wanted it on the backup). Assuming, as I do, that I need a sure start at those numbers, is it better to have the HVAC contractor put one on when they install or should I wait for the TESLA folks later (they built the system with the new HVAC specs, FWIW)? Had seen some compatibility issues on the boards, so wondered if I should just have one put on now.


Active Member
Mar 28, 2017
Orlando, FL
I would definitely talk to the HVAC people about it, at least. It’s my understanding that some HVAC equipment manufacturers make soft start units designed to be used with their equipment. If your manufacturer makes such a unit, then it would certainly make sense to install that one. Tesla would likely just install a generic one. The generic one would probably work, but again, if you can get one built for your system that seems like a better option.


Well-Known Member
May 3, 2017
Tesla installed my soft starts, works very well after they fixed the frequency problem when off grid, so make sure they don't crank your frequency too high when off grid or else the soft-starts won't work.
Note: that frequency offset is used to control the output from solar inverters on some setups. The inverters and PW all need to be set up in the correct range.

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