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Hoping for some much needed help. The other day my lights flickered and half the power and outlets went out in my home. They have gone and off periodically since then, spontaneously shutting off at times with nothing “triggering” it. My electrician couldn’t find anything, but not sure how well he looked. I called my power company and they said all is well outside and at the meter. The areas I am losing power to are not on the same leg, the weird thing is, is that I can get the power to go back on by turning on a few faucets to hot water and getting my well pump to fire up. It seems like once the well kicks on, its restarts the power to everything.enter image description here

  • Comments are not for extended discussion; this conversation has been moved to chat. – Michael Karas Feb 5 at 4:43
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    Am I seriously seeing a power lug through your 'main breaker' slot? If that's so, dear lord, please get a competent electrician out there. And the power company- they're going to have to shut it down- you've lost a leg somewhere. – J.Hirsch Feb 5 at 21:08
  • Any competent electrician would be able to sort this out. The fact that there is no main breaker in the panel is a bit odd. – Hot Licks Feb 7 at 3:13
  • 'fired up' - I see what you did there (hopefully, not literally :). I initially blamed the electrician too, but if the power company didn't test their equipment with the meter pulled, then absolute shame on them. – Mazura Feb 7 at 4:34
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Call the power company back. You lost a pole.

Here's how your house normally works.

enter image description here

Here's what happens when a hot wire breaks.

enter image description here

That's simple enough, right? Half the 120V loads croak. And all the 240V loads... right? But wait. What if they are both on? Say that water heater cycles on.

enter image description here

This. This is why the electrician and the power company read near-120V on both legs, declared victory and went home. At the time they checked it, the water heater or other 240V load happened to be cycled on. What they neglected to check was the voltage across the 2 hot legs, which should have read 240V but would have read perhaps 7 volts.

I bet they actually read 122 and 115V, and told you the difference was normal.

Next time they come out, switch all 240V and MWBC breakers off to stop that goofy flow pattern you see in the third diagram. Then, they'll be able to see the problem.

But the dead loads aren't all on the same side of my panel!

Because you're presuming left and right are the two poles. That's only true on a Pushmatic panel. Here's how most panels are actually laid out, and now see if that matches the location of your dead breakers.

This will fry your well pump!

If you look at the diagram carefully, you can see that the water heater is in series with the loads on the dead pole. And, there's only 120V for both of them. It all depends on how much load the water heater is drawing versus the other loads, but if the loading is modest, the voltage will be near 120V. If you have 13A of 120V load, then it will be 60V to the water heater and 60V to the 120V loads.

The water heater is perfectly fine with that, because it's a simple resistive load that will work on any voltage below spec. It is able to slowly re-heat the water in the tank even on 1/4 voltage (1/16 wattage), and eventually it shuts off. That's how well-insulated water heaters are.

The well pump, on the other hand, will be one unhappy puppy. Motors do not like this kind of massive undervoltage treatment, and it will burn out that motor PDQ. Given where most people put their well motors (at the bottom of the well), you really don't want that.

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    The power company usually knows to check for 240 across poles. My guess is a bad contact on the main breaker. When the water heater kicks in, it's enough load to make contact but not enough to weld it shut., so when the heater turns off the open circuit remains. – JACK Feb 4 at 13:19
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    @JACK, its more likely that the power is flowing through the water heater to power the other leg when it kicks on since a 240v circuit is attached to both legs. – JPhi1618 Feb 4 at 15:55
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    @JPhi1618 Surely could be. 25 years with power company and have seen some pretty crazy stuff. – JACK Feb 4 at 16:25
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    It might be worth mentioning how stalled pumps get a quadruple whammy compared with running ones: (1) The amount of power going through them when stalled will be higher than when running; (2) parts of the circuitry which are only designed for intermittent operation (the starting caps) will be powered up continuously; (3) all of the power going into a pump will be converted to heat rather than going out in the form of useful work; (4) parts of the pump that should be cooled by flowing liquid won't be cooled if the liquid isn't flowing. – supercat Feb 4 at 17:00
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    I don't understand any of this, but I like it. – bornfromanegg Feb 5 at 11:14

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