All major brands of panels sell tandems. Quick and easy to install (unless the box is already full of tandems).
Who ever installed t.hat missed the whole point of an interlock. It is supposed to be installed on the MAIN panel. This reduces costs and let's you CHOOSE, at the time of the power outage, what circuits you want to power.
That interlock looks fine to me, There is no way the main back fed breaker and the back fed breaker from the generator can both be on at the same time. The generator will just power the circuits in that panel.
Exactly. I had a transfer panel at my old place. More expensive, more complex and not nearly as flexible. New place I did the interlock.
The main box is right next this box.
Wiz, you need to get out more. My last house had twice that many 240 breakers. 3 heat pumps + air handlers, 1 AC + air handler, two ovens, range top, two water heaters, hot tub, one mini split, 3 branch circuit breakers to feed other subpanels.
Tandems will only install in panels that will accept them. Not all panels and not all spaces will let a tandem be installed. some have a notch in the buss, others like Square D QO and Eaton CH are a little different. A panel is listed only for so many circuits, it is a violation to exceed that number. I understand they make the "cheater" style tandems, but you should still not exceed the maximum circuit rating. Your newer panels will have it on the label if tandems are accepted.
IANAE, but I have not run into any panels that will not accept SOME tandems. May be a limited number. Last time I needed to add tandems, the limit was 4 and that was exactly what I needed !
Not really. Nothing says this has to be on the main panel. I did the same thing in a small sub panel. In retrospect the main panel would be more flexible but that was 18 years ago and the availability of panel interlocks was limited. Works fine and supplies ESSENTIAL loads.
The interlock has to be in the same panel that supplies the loads you want to run off the generator. If you do it to the garage panel you will only power the garage panel and not feed back to the main panel. The whole point of an interlock is to not allow power to be fed upstream to the source for the panel.
A friend just had a generator install (20kw) quoted from Costco. They said $11k-$15k for the install of transfer and generator. That's the highest I've seen, but there is a lot of demand.
sounds like theyre confusing the code that requires that for ATSs
The vast majority the installed base of Eaton CH panels are not made nor listed for twin breakers, although they will plug in anywhere, if they flop around on the lug end then they are not made for that panel or that position in the panel .
