Reminder: Never connect a generator to home wiring without transfer switch

Mark Tinka mark at
Wed Aug 25 13:19:35 UTC 2021

On 8/23/21 19:53, Sean Donelan wrote:

> Currently a problem in the north-east USA, but applicable after every 
> storm.
> People in the south have more experience with hurricanes, and are used 
> to this advice.  But apparently, some folks up north aren't in practice.
> Never connect an electric generator to home electrical wiring without 
> installing a transfer switch to disconnect power from the electric 
> grid.  Back feeding electric power into the utility lines is dangerous 
> for the repair crews working on utility lines.

Standard advice when you do any kind of distributed or embedded 
generation outside of the grid.

Mistakes like these are more likely to come from DIY'ers who put in 2hrs 
of Youtube and think they are suddenly qualified electricians.

Same advice applies to solar or stationery storage inverters. Typically, 
these are automated enough to disconnect from the grid after an outage, 
if you don't have a local battery; or the battery inverter will isolate 
away from the grid in case of grid failure, but still form its own 
micro-grid for the building. So back-feeding into the grid is not a concern.

But for combustion generators, yeah, have a qualified electrician do the 
install. Just saves time, money and lives.


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