Hot main = bad main?

[ranger_dood]

To start off, this is a house question, not a garage question, so I apologize.

Background - 95* outside and climbing, I have one large 110v window AC unit running downstairs, and one small 110v unit upstairs. Home from work today, so I'm doing laundry, which means the washer and electric dryer are going. I have no doubts that my fridge and freezer (two upright units) are probably running quite a bit to keep my snacks and beer cold. Add in some various smaller loads... two PCs, an LCD TV... whatever you like.

Panel is a GE... was installed when they converted over from the original fuse panel. Main (and service) is 100A, which I've been concerned about in the past. Mostly just due to age, and I'm more "used" to seeing 200a service (and indeed, that's what was on the listing when I bought the house. oops..._).

I went down to check the main today, because I've been considering upgrading the service, or at least replacing the panel with something that has easier-to-find breakers. Using my IR gun, I found that the top pole on the main was at 162*F, and the bottom pole read 186*F, as measure on the side of the casing with the front off the panel.

Took my clamp ammeter, and read one leg at 13.3A, and the other at 16~A. To me, this doesn't seem right... because I measured just a single hot leg going out to the dryer, and got a reading of 23A on that leg alone.

So a few questions- Is it normal for a main to get that hot, and still not trip? Am I approaching the limits of my 100A service? Is the main just old, and needs to be replaced? Why am I seeing such low amperage on the main legs, when other lines are showing higher? Can someone please turn the heat down?

Oh, and - Can you change out a panel, without pulling the meter? Should I even consider asking an electrician to attempt this, or will they just laugh at me? Is it worth replacing the panel with another 100A, or take that opportunity to do a full service upgrade? The pole with the transformer is right outside my front door, and actually on the corner of my property.

Thanks for any advice or musings you might be able to give. I'd rather not burn the house down just because I need clean (and dry) shorts.

 

[pattenp]

I don't have any comments on all the other stuff you've asked about, but I know that panels have been changed without pulling the meter, but I sure as hell wouldn't try it.

...........
Oh, and - Can you change out a panel, without pulling the meter? Should I even consider asking an electrician to attempt this, or will they just laugh at me? Is it worth replacing the panel with another 100A, or take that opportunity to do a full service upgrade? The pole with the transformer is right outside my front door, and actually on the corner of my property.

Thanks for any advice or musings you might be able to give. I'd rather not burn the house down just because I need clean (and dry) shorts.

 

[hammlm]

I wouldn't try to replace the panel without popping the meter out of the socket. I am no longer an electrician, but I've changed a good number of main panels without changing the service, and have never not popped the meter.

I did, however, move my meter base to a temporary location and then re-sleeve the service conductors (underground feeders) and re-attach it at my house during an addition project. I would never do that again without calling the POCO for a disconnect. My nerves aren't that good anymore.

With regards to the anomalies in the current readings --- I can't imagine, other than I would suspect your metering equipment first. What you describe doesn't make sense, if the dryer was still on and running when you checked the mains.

You are in PA. Who is your electric provider?

 

[ranger_dood]

Here's a little more info... I went through and checked all the breakers amp draw, and then rechecked the mains. I don't know what the problem was before... maybe I didn't have the clamp all the way closed or something. But what I found was that with all the loads running, and the washer revving up for a spin cycle, I had 40.9A on the top leg, and 37A on the bottom. At these loads, I measured 170* on the top leg, and 222* on the bottom.

This makes me very concerned, because I should be able to have about 85A draw on each leg continuous, per the breaker size of 100A.

In this case, would you then recommend just swapping out with another 100A panel? Or take the extra time and money to do a full service upgrade. The house is only a little bit bigger than 1000 sq ft, and the summer time is the highest draw, as I have natural gas heat.

Oh, and my electric supplier is PPL.

 

[KenC]

I would check the incoming wire connections on the main. Be sure they are tight and clean. If aluminum, check for oxidation.


If that's ok, pull the main breaker and examine the tension where the contacts meet the bus. Could be oxidized or weak.

Either of the above can create heat.

Can't think of any reason for the high temp reading.

But, I'm no electrician but do play one at my home and shop.

 

[mrb]

put a multimeter across the breaker one pole at a time (one probe on line and one probe on load of the same pole) and see how much voltage drop your getting across the breaker. Do this to each pole and respond with the results. You shouldnt have that much temperature rise with <20 amps of load.

 

[Aceman]

I really don't think this is the time or place to have an uneducated diy'er putting his meter leads on the line side of the main.

Call an electrician.

 

[mrb]

I really don't think this is the time or place to have an uneducated diy'er putting his meter leads on the line side of the main.

Call an electrician.

good point.

 

[rlitman]

I measured 170* on the top leg, and 222* on the bottom.

Well, 222F is above the temperature rating of the insulation on your service. If it truly is that hot, you have a very serious problem.

 

[nehog]

Agreed, the temp readings are so high, I'd recommend shutting off all non-essential loads and getting an electrician out ASAP. There is clearly something seriously wrong with this setup.