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Backfeeding houses with generators is indeed a killer feature... but not in the way you mean. It can be done safety, but when done incorrectly (if the house i

Backfeeding houses with generators is indeed a killer feature... but not in the way you mean. It can be done safety, but when done incorrectly (if the house isn't removed from the grid first) it can kill linemen. It's a good thing most generators a homeowner might causally buy at the hardware store don't have this feature. Unfortunately I've seen male-to-male extension cords sold online for this purpose. I think these are actually illegal, at least in some places. https://www.cdc.gov/disasters/elecgenerators.html https://www.cdc.gov/disasters/elecgenerators.html

PaulDavisThe1st 5y ago
> Backfeeding houses with generators is indeed a killer feature... oh, you mean like solar PV on-grid setups ...
- wearywanderer 5y ago
  Those are generally fine because they are generally installed and configured by licensed electricians. Generators with suicide-cables installed by homeowner Joe Blow are the problem.
  - FooHentai 5y ago
    Close. It's not the electricians qualifications that make it safe, it's a feature in generating home inverters called 'anti-islanding'. A correct install is of course also required as it's possible to screw up and unintentionally cripple this important safety feature.
- michaelt 5y ago
  Your basic solar inverter monitors the grid voltage, and if the grid goes down it stops generating. Needless to say, if you're looking for a backup power source this isn't a property you want.
  - PaulDavisThe1st 5y ago
    d'oh. i'm an idiot. (an idiot who the state of NM certified last year to install his own on-grid solar PV system, so doubly an idiot!)
  - mike_d 5y ago
    People with generators and suicide cables know to shut off the main breaker. Per my buddy who is a lineman in a rural area, DIY solar systems in cabins and such are much more of an issue.
  - rootusrootus 5y ago
    Yeah, our local utility won't let you feed the house from panels without grid power unless you also install a battery.
- rainbowzootsuit 5y ago
  All of the grid tied solar systems are able to conform to the IEEE 1547 standard. Amongst the particulars are a 300 second reconnection time if there's an interrupted grid to protect utility workers. Most (all?) USA utilities mandate this standard. Some battery systems, like the Tesla Powerwall include a contactor that allow their microgrid battery systems to conform to the standard without a loss of power to the site they power. https://standards.ieee.org/standard/1547-2018.html https://standards.ieee.org/standard/1547-2018.html
rootusrootus 5y ago
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?
wrycoder 5y ago
I assume Ford’s lawyers are all over this, as the liability is immense, and Ford has deep pockets.

PaulDavisThe1st 5y ago

> Backfeeding houses with generators is indeed a killer feature... oh, you mean like solar PV on-grid setups ...

wearywanderer 5y ago
Those are generally fine because they are generally installed and configured by licensed electricians. Generators with suicide-cables installed by homeowner Joe Blow are the problem.
- FooHentai 5y ago
  Close. It's not the electricians qualifications that make it safe, it's a feature in generating home inverters called 'anti-islanding'. A correct install is of course also required as it's possible to screw up and unintentionally cripple this important safety feature.
michaelt 5y ago
Your basic solar inverter monitors the grid voltage, and if the grid goes down it stops generating. Needless to say, if you're looking for a backup power source this isn't a property you want.
- PaulDavisThe1st 5y ago
  d'oh. i'm an idiot. (an idiot who the state of NM certified last year to install his own on-grid solar PV system, so doubly an idiot!)
- mike_d 5y ago
  People with generators and suicide cables know to shut off the main breaker. Per my buddy who is a lineman in a rural area, DIY solar systems in cabins and such are much more of an issue.
- rootusrootus 5y ago
  Yeah, our local utility won't let you feed the house from panels without grid power unless you also install a battery.
rainbowzootsuit 5y ago
All of the grid tied solar systems are able to conform to the IEEE 1547 standard. Amongst the particulars are a 300 second reconnection time if there's an interrupted grid to protect utility workers. Most (all?) USA utilities mandate this standard. Some battery systems, like the Tesla Powerwall include a contactor that allow their microgrid battery systems to conform to the standard without a loss of power to the site they power. https://standards.ieee.org/standard/1547-2018.html https://standards.ieee.org/standard/1547-2018.html

rootusrootus 5y ago

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?

wrycoder 5y ago

I assume Ford’s lawyers are all over this, as the liability is immense, and Ford has deep pockets.