1

I have a push matic box, where over the years breakers will go bad. Luckily, they are after the main lighting breaker that shuts off the bottom of the buss bar. I feel comfortable working on those and have replaced several over the years.

New item, the main lighting breaker is starting to fail. The problem is, of the four screws connecting it to the buss bar, 2 are connected to the upper part that cannot be switched off with out turning off the power at the meter; I am unable and unwilling if I could, to do that.

Question..

I have my class 0 insulating gloves, and my 1000v rated insulating drivers; are experts here comfortable pulling that break without turning the main power off outside? Is it completely irrational to do so?

I am selling the house in a year or so, and they are demoing these houses for bigger, so I’d rather not upgrade the panel. The panel has been good to us the last 30 years.

All input is welcome.

Thank you. Hahn enter image description here

4
  • 2
    I take it you've tried contacting your utility and asking them nicely if they're willing to schedule a brief power shutoff? – ThreePhaseEel Feb 8 at 12:45
  • 2
    FWIW, long ago I needed to replace a fuse box with no main disconnect with a new breaker box. I called the local utility and asked about having the meter pulled. The attitude was pretty much "we don't care why you're doing whatever you're doing, but if it's safer without power we're all for it." Any time, day or night, weekends, just call and we'll have someone out promptly. Sure enough, did the work on a weekend. Someone came out, pulled the meter and capped the socket, and said she'd be in the area for a few hours. Called back, meter replaced, circuits checked, meter sealed. – HABO Feb 8 at 15:41
  • 2
    Why are you unwilling to turn off power at the meter? That's the normal way stuff like this is done. What you're asking is not impossible, but I absolutely wouldn't recommend trying it yourself unless you've had training on it -- it's very dangerous if you don't know exactly what you're doing. Like EdBeal mentions, even simple stuff like dropping a screw could cause an arc flash that could kill you. OTOH, cutting power at the meter is easy and you don't even have to do it yourself: just call your utility to turn it off, and call again to have it turned back on. – Nate S. Feb 8 at 17:06
  • 2
    @Nate s you are correct I have dropped screws before I have been lucky, when working with the lead electrician he dropped a screw and it vaporized we saw the arc marks never found anything but brown pants (we were lucky but both had hot gear on) he started using rubber cement after that he was close to retirement and that was his first bad arc flash so it even happens to us. – Ed Beal Feb 8 at 19:17
1

If doing this first turn the breaker off or all of the loads on the breaker (yes I understand it’s still live). Using the proper gear electricians do this all the time. I would add a face shield just in case. I have to wear a green one that I think makes it more dangerous because it makes it harder to see (a few years I started using an auto darkening welding hood it covers the face and is clear until a flash). If I remember the screws on the pushmatic are captured so you won’t drop the screws, if they are not this will be the dangerous part of the job removal and installing the screws. I carry a small jar of rubber cement, some times called contact adhesive. I dip the screwdriver tip (a proper screwdriver will be a snug fit without the glue) let the glue dry only takes a minute. Remove the screws. The contact adhesive is sticky and helps hang onto the screw if it is not captured. Dropping the screws can cause a short that may end in a arc flash. The protective equipment is there for this possibility on top of the live circuit. Wear cotton clothing nothing that can melt.

Use caution, loads turned off, face shield, gloves, insulated tools and heavy cotton clothes and caution while doing the work.

Just to make clear the loads are turned off so when the screws are loosened there is no arcing while coming out if the breaker is stuck on. Make sure the new breaker going in is off so it doesn’t arc on contact.

It has been quite a few years since working on a pushmatic I think the screws are captured but may be wrong the rubber cement although can be messy can be a real aide on the tip of the screwdriver

1
  • 3
    And this is why I'd call a guy like Ed to do this if it had to be done with the power live. He's made of sterner stuff than I! Of course, if I'd had the training, practice and experience, I'd be much more comfortable taking on a job like this, too. – FreeMan Feb 8 at 17:56

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.