TMC is an independent, primarily volunteer organization that relies on ad revenue to cover its operating costs. Please consider whitelisting TMC on your ad blocker and becoming a Supporting Member. For more info: Support TMC

New Install Tomorrow (Solar + 2 Powerwalls)

Discussion in 'Tesla Energy' started by plucas777, Dec 4, 2019.

  1. plucas777

    plucas777 Member

    Joined:
    Dec 4, 2019
    Messages:
    25
    Location:
    Orlando, FL
    I have a few questions regarding an attempt at a "Whole Home Backup" install.

    I live in Florida and in my area we seem to have short spurt outages from .5 - 3 hours outages during the rainy season quite often. Aside from the obvious scenario of a hurricane, the main reason I got the Powerwalls was in hopes to continue life uninterrupted by the shorter outages due to random thunderstorms.

    I was wondering if it is possible to power a 3.5 ton A/C with two Powerwalls for a short period of time. It seems that the information I am getting ranges from "it will do it but just drain the batteries quicker" to "it depends on if the LRA value is less than the 60A that two powerwalls can provide". I am not sure which one of those answers is accurate. The LRA of my outdoor unit is 109.

    If the LRA answer is correct, would it be smart to let them install the batteries to back up the whole home and then later install a "soft start" module. I was thinking in this scenario I'd have to avoid turning the A/C if I was in backup mode until I get the soft start module installed.

    I guess ultimately, I am trying to avoid having them setup my system in a way that will add more work later if I want to backup the entire house later"


    Forgive my ignorance as I am new at all of this.
     
  2. plucas777

    plucas777 Member

    Joined:
    Dec 4, 2019
    Messages:
    25
    Location:
    Orlando, FL
    Just saw this post from user runfarnn -

    "Here is what the Tesla engineer designing our system provided as specs for a 2 PW set up (with two A/C units).

    The LRA for each unit is 58 amps or less

    OR

    The LRA is 140A or less AND the unit has a scroll compressor."



    I have confirmed that my unit does indeed have a scroll compressor. So does a combo of LRA 109A and scroll compressor sound safe for two Powerwalls ?


    Thanks.
     
  3. chrisbailey13

    chrisbailey13 Member

    Joined:
    Sep 17, 2019
    Messages:
    96
    Location:
    Central Florida
    I recently had Solar and Powerwalls installed in FL. I am backing up two 3 ton AC units and the Tesla installers installed soft start modules on each unit to compensate for the hard starts. Your team should be doing the same if the AC unit is a part of your Powerwall backup design.
     
  4. bkp_duke

    bkp_duke Active Member

    Joined:
    May 15, 2016
    Messages:
    4,250
    Location:
    San Diego, CA
    If you have the scroll compressor, it works just like a soft start device, no need to have them install that. You should be good to go.

    In my experience, Tesla engineering was very conservative, and if they have any indication you will push past peak draw, they won't let you wire up a whole house backup (this is the reason we had to go for 3 PW2s, instead of the originally planned 2).
     
  5. plucas777

    plucas777 Member

    Joined:
    Dec 4, 2019
    Messages:
    25
    Location:
    Orlando, FL
    I guess the only difference than my install and others is that I didn’t work with Tesla. I worked with a local company called Maximo Solar. They had several Powerwalls on hand so I jumped on it since I was doing solar anyway.

    Hopefully it either works like the above poster or the installers can put a soft starter in place.
     
  6. plucas777

    plucas777 Member

    Joined:
    Dec 4, 2019
    Messages:
    25
    Location:
    Orlando, FL
    Thanks to you all.
     

Share This Page

  • 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