Interlock vs. throwing the main circuit breaker for generator powering a house

[4570Man]

Maybe anyone that’s smart enough to grab onto a dropped high voltage line hasn’t had time to reproduce before getting electrocuted. I’m not claiming back feeding is safe or smart but there’s plenty of other hazards.

 

[TheMan419]

In addition most people add up watts and have no clue regarding reactive power. Now they have 4990watts on a 5000W Generator and wonder why the breaker is tripping even through the engine isn't lugging down. All because of that 7000Volt Amp load that they think is 4990 watts.
Far better if the prospective generator purchaser added the amps. Then increase the generator size by at least 150% to have some reserve.

Or you know have a conversation with an electrician when getting ready to install a generator. I have a 6900 w running (8000 w peaking) generator. That was what we needed at the old house. When we wired the new house the electrician and I discussed what would be running during an outage. He told me to make sure the fridge, both pumps on the boiler and the well pump were not running all at the same time. So if I want to go take a shower I just flip off the circuit for the fridge and I am good.

Odds are only one pump for the boiler would kick on at a time, but on a rare case I hear them both kick on at the same time.

 

[kco]

Maybe anyone that痴 smart enough to grab onto a dropped high voltage line hasn稚 had time to reproduce before getting electrocuted. I知 not claiming back feeding is safe or smart but there痴 plenty of other hazards.

The actual hazard is not always that obvious. It is not uncommon to have what caused the blown utility fuse still hanging from the primary line and free of the neutral. If it is blocking a roadway someone could be tempted to remove it, not recognising the hazard that it is on the primary.

I saw a similar hazard several years ago while going to town. A spindly birch was leaning on the 15KV powerline, and the power was still on. I had an appointment but stopped at the neighbour's across the road from it and got her to call 911(as BC Hyrdo requests for a downed line) and to make sure nobody approaches the tree or tried to clear it. BC Hydro had been out and cleared it by the time I returned a few hours later.

Anyhow, we all seem to agree back-feed is dangerous and must be avoided.

 

[4570Man]

The actual hazard is not always that obvious. It is not uncommon to have what caused the blown utility fuse still hanging from the primary line and free of the neutral. If it is blocking a roadway someone could be tempted to remove it, not recognising the hazard that it is on the primary.

I saw a similar hazard several years ago while going to town. A spindly birch was leaning on the 15KV powerline, and the power was still on. I had an appointment but stopped at the neighbour's across the road from it and got her to call 911(as BC Hyrdo requests for a downed line) and to make sure nobody approaches the tree or tried to clear it. BC Hydro had been out and cleared it by the time I returned a few hours later.

Anyhow, we all seem to agree back-feed is dangerous and must be avoided.

So if you come upon a broken line how are you going to determine which side of the live was energized? Touching a broken line without verifying it’s dead and putting measures in place to verify it can’t be energized is really asking for it.

 

[RickB]

So if you come upon a broken line how are you going to determine which side of the live was energized? Touching a broken line without verifying it’s dead and putting measures in place to verify it can’t be energized is really asking for it.

So is working on a verified dead line when somebody backfeeds into it “asking for it”?

 

[4570Man]

So is working on a verified dead line when somebody backfeeds into it “asking for it”?

Yes, there’s far too many geniuses with generators to assume that won’t happen. BTW, I have a real transfer switch so I’m not making excuses for myself, but if you think the possibility doesn’t exist you better pay your life insurance and buy some insulated gloves.

 

[RickB]

Yes, there’s far too many geniuses with generators to assume that won’t happen. BTW, I have a real transfer switch so I’m not making excuses for myself, but if you think the possibility doesn’t exist you better pay your life insurance and buy some insulated gloves.

Oh, no, I get it. I had a full transfer switch where I had a generator. I don’t have any backup (yet) here.

 

[kco]

So if you come upon a broken line how are you going to determine which side of the live was energized? Touching a broken line without verifying it痴 dead and putting measures in place to verify it can稚 be energized is really asking for it.

That was the point of my post--you cannot determine if a line is energized or from what direction. Thus, assume it is always energized. Although it is deenergized now, it can be energized 1 second from now if someone back feeds with a generator or if the utility personnel decide to close it in one more time to test it. We used to do that 50 years ago but I'm not sure it is as common today. From a lineman's point of view a line is not deenergized until it is grounded. So if the primary conductor is broken they must ground it from both directions before starting repairs.

Your previous post seemed to suggest those who are not aware of the hazard are to blame because they are stupid. If a back feed happens due to a standby generator, that is the real culprit, and it can be out of stupidity or unawareness of the danger created if one does not take the time to learn how to operate it properly.

Those of us with generators have a responsibility to learn how to use them safely.

 

[MossRoad]

So is working on a verified dead line when somebody backfeeds into it “asking for it”?

How do linemen work on dead lines? Do they ground out every line before they touch it? Do they were appropriate PPE when handling it? Sticking a meter only verifies it is dead right now. It doesn't account for anything that may happen in the next instance. I don't know, as I'm not a lineman. All I know is I am required to lock out tag out and verify every circuit I change a light switch, outlet, or ballast on at my employer. What's the procedure for a lineman?

 

[kco]

How do linemen work on dead lines? Do they ground out every line before they touch it? Do they were appropriate PPE when handling it? Sticking a meter only verifies it is dead right now. It doesn't account for anything that may happen in the next instance. I don't know, as I'm not a lineman. All I know is I am required to lock out tag out and verify every circuit I change a light switch, outlet, or ballast on at my employer. What's the procedure for a lineman?

For a lineman a line is not dead until it is grounded. It is grounded with a cable from the phase(s) to the neutral. As stated above if a conductor is broken they will ground both sides. We also used to (50 years ago) have "HOLD" tags for when we opened a switch and it was hung by the switch. Only the person installing the "HOLD" could remove it or authorize its removal. But that was 50 years ago, they may do it differently now but I suspect it is similar.

That is for primary lines. 240/120v were worked energized with just leather gloves, I'm not sure they do that now.