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I recently lost power to my fridge, I couldn't figure it out for the life of me until I removed all of the receptacles and found the incoming power directly from the breaker, from ground to hot it was 120volts and from hot to neutral it was 14 volts, I was dumbfounded until I wiggled the white wire in the breaker box and sparks flew, there was a hairline Crack that became brittle in the neutral wire

I cut the coating down on the Romex wire and retightened and got 120 volts again

My problem: I was getting reaclimated to the furnaces components and wiring setup the other day when I found that the two 60A breakers in the furnace, one was reading 120volts and the other was at 113 volts

My question: Is my house so old that the wiring is just deteriorating after 36 years or should I just update the breakers and strip down all the wires so it gets a good connection again

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  • This Crack was a couple centimeters from the neutral screw in the breaker box, it was straight and didn't look like it had any wear so I was left scratching my head for a minute, I turned off the main breaker, cut it down, then retightened
    – user70085
    Commented Oct 7, 2018 at 20:03

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Ironically your wiring system has reached 30 years which is its half life. Meaning from here through the next 30 years an average system can experience 50% failure of it's components. This is just a statistical average and does not apply to any one system.

I would start by performing some maintenance on the panel. First I would remove every conductor from it's panel connection, including neutrals and inspect and clean the conductor. Then with a voltmeter carefully turn it on and check to see if you are getting 120V on each pole of the breaker to the ground bus. Turn the breaker off and reconnect the circuit, turn it back on and recheck the circuit to make sure your voltage is OK. Then repeat all the way through the panel. I would start with the main breaker and go all the way through.

Second as long as I already had the panel open I would remove each breaker and check the resistance through the breaker with an ohmmeter. the resistance on all breakers should be consistent throughout the panel. If I experienced a higher resistance than normal or an open circuit, I would replace that breaker and I would check the connection to the bus for any corrosion, coloration or arcing. I would also do the same at the breaker conductor connection.

Then once I have reassembled the panel. Perform a voltage check by measuring the voltage from the main service feeder to the ground and the neutral, and check it against the voltage between the breaker post and the neutral/ground to make sure it is consistent with the incoming service voltage. It should not vary much more than one volt.

In short you are indicating that the panel connections are loose and it is not just with one circuit. So lets clean it up and see if we can get it back to proper working order before calling in someone for a complete panel replacement.

Good luck and stay safe.

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  • Thank you, would it be wise to change out all of the wiring since it has reached half it's life
    – user70085
    Commented Oct 7, 2018 at 20:01
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    That would be my last option. Your installation may be old but your wiring in the 1980's was probably thwn/thhn or the older tw/thw type both are a plastic type insulation which really doesn't go bad over time unless your system was at one time under a high stress and created a lot of heat. If what I just said was true then your failures would show up at your terminal and splice points before your insulation failed. That's why I recommended what I did. Think of the expense of replacing your wiring. My next move would be a panel replacement if necessary.
    – Retired Master Electrician
    Commented Oct 7, 2018 at 20:11
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Are the breakers the correct type?

The first thing you do is make sure all your breakers are correct for the panel. When people post pictures of their panels, we see A LOT of "alien breakers" where they have brand X panel and someone just slapped in a brand Y "because they fit". They don't fit. They snap in, but the insertion pressure is obviously different and wrong, and they are gripping the busbar in an inefficient and misshapen way, and they will arc and ruin the busbar if they are heavily loaded.

That said, there are "classified" breakers. Siemens QD breakers are 3/4" wide and made (and UL listed) specifically to fit only Square D QO panels - they won't even fit Siemens panels which use 1" wide breakers!

ThreePhaseEel is a subject expert on this, so tap that knowledge!

Are breakers correct for wire size?

Breakers protect wires and devices. Compare the wire size to the breaker size. Any #14 on a 20A breaker? Any #12 on a 30A breaker? Investigate and either downbreaker or rewire.

When homeowners get frequent breaker trips on a circuit due to their own incompetence in overloading it, they often swap in the next size larger breaker simply to stop the trips. This is what we're hunting for.

If you find a dedicated circuit with a motor load with seemingly oversized breaker and undersized wire, shoot a picture of the motor nameplate and come on back and describe the situation to us. There are certain exceptions where this is allowed.

Are Multi-wire branch circuits (MWBC) on 2-pole breakers?

Search for every instance of "two hots and a neutral" -- typically in /3 cable, black red white. Make sure every one of them lands on a 2-pole breaker.

There is a wiring technique called MWBC where two hots share a neutral. That is fine, but it needs to follow extra rules to be safe. It is safety-vital that the breakers be on opposite poles. It's also important that both legs have common maintenance shutoff, so one handle throws them both off for sure. You can slickly solve both problems by feeding the circuit from a 2-pole breaker. (NOT a double-stuff; the handles cannot throw independently!)

There are other ways to do it, but that is the simplest.

Is aluminum wire present?

Aluminum or copper-clad-aluminum wire is special. It has two special needs.

  • The wire must be 2 sizes larger (smaller numerically) than copper. That means a 15A breaker needs #12 wire......... A 20A breaker needs #10....... And a 30A breaker needs #8. Make sure that is so.
  • Fit AFCI breakers. Back in the day, when aluminum wire was popular, many electricians made very bad choices of terminations - they wired aluminum to receptacles and switches that were rated copper-only, or devices that were hastily rated for aluminum without proper testing. This caused fatigue or dissimilar metal corrosion. Both of these fail by arcing. Arc-fault breakers are a silver bullet.

This used to be a much harder, scarier problem. Thanks, AFCI.

Well, it would be good at some point to follow up and replace old receptacles, switches and splices with CO-ALR (R for Revised) rated devices. Wire nuts should never be used, not even the purple ones; use Alumiconns.

AFCI anywhere else you're worried about.

It really is a silver bullet.

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  • I replaced all of the outlets and switches a few years back, found a few loose wires in old outlets, I guess now it's time to update the panel, thanks
    – user70085
    Commented Oct 8, 2018 at 1:10

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