3 ms·

Yes you definitely have to get it installed by a licensed electrician (and possibly approved then by the local utility) if you are going to backfeed your own ho

Yes you definitely have to get it installed by a licensed electrician (and possibly approved then by the local utility) if you are going to backfeed your own house. It is good that people are aware of the risk, but in reality the risk is quite low. It is standard procedure for a lineman to ground a line he's about to work on, to mitigate the risk of any power source feeding it. But I'd never advocate a DIY setup. But damn near everyone I know with a portable generator has a suicide cord and just flips the mains. Ah well.

brianwawok 5y ago
I do hear this kill a lineman a lot as soon as any talk goes into backup power. How many linemen are killed a year in the US due to backup generators or similar? Are there no procedures they can do to work on lines safer?
- eigenvector 5y ago
  Are GP mentioned, the safety procedure to protect you from a line you're working on becoming inadvertently energized is temporary protective grounding. A grounding jumper is connected to each phase of the power line near the work location so that the worker touching the line works in a zone of equipotential. Because everything the worker is touching bonded together, if the line becomes energized the worker's hands and feet are elevated to the same voltage simultaneously, so there is no potential difference across the body and no current flows through the worker. But since lives are at stake here, we prefer to have layers of protection rather than just one thing. Grounding jumpers can fail if not properly connected (a large mechanical force will be applied to the jumper when the phase-to-ground fault current flows through it). Bottom line, respect the electrical code and connect generators through a transfer switch. These rules are in place for a reason.
  - mycall 5y ago
    Could an isolating transformer be an alternative to connecting generators through a transfer switch?
    - swiley 5y ago
      Transformers only block DC. Unless your house is wired for that (pretty rare in almost every country) You'll backfeed AC which will go through transformers. In fact it's likely the transformer on the street between your house and the network that's responsible for the death of the linemen. IIRC that's a step down transformer (so step up when run backwards like this.)
Scoundreller 5y ago
Shouldn't this be called a "homicide cord"? It's the unsuspecting lineman that'll be harmed, not the homeowner, right?

brianwawok 5y ago

I do hear this kill a lineman a lot as soon as any talk goes into backup power. How many linemen are killed a year in the US due to backup generators or similar? Are there no procedures they can do to work on lines safer?

eigenvector 5y ago
Are GP mentioned, the safety procedure to protect you from a line you're working on becoming inadvertently energized is temporary protective grounding. A grounding jumper is connected to each phase of the power line near the work location so that the worker touching the line works in a zone of equipotential. Because everything the worker is touching bonded together, if the line becomes energized the worker's hands and feet are elevated to the same voltage simultaneously, so there is no potential difference across the body and no current flows through the worker. But since lives are at stake here, we prefer to have layers of protection rather than just one thing. Grounding jumpers can fail if not properly connected (a large mechanical force will be applied to the jumper when the phase-to-ground fault current flows through it). Bottom line, respect the electrical code and connect generators through a transfer switch. These rules are in place for a reason.
- mycall 5y ago
  Could an isolating transformer be an alternative to connecting generators through a transfer switch?
  - swiley 5y ago
    Transformers only block DC. Unless your house is wired for that (pretty rare in almost every country) You'll backfeed AC which will go through transformers. In fact it's likely the transformer on the street between your house and the network that's responsible for the death of the linemen. IIRC that's a step down transformer (so step up when run backwards like this.)

Scoundreller 5y ago

Shouldn't this be called a "homicide cord"? It's the unsuspecting lineman that'll be harmed, not the homeowner, right?