IR image question

[marcram]

I am an infrared inspector and typically do commercial roofs. I was asked to shoot an electrical sub panel in a condo by a realtor and this is what i found. The hottest conductor in the pic is the neutral coming from the main panel, it was over 105 degrees when shot individually. It was hot only at the terminal. The other two conductors, (the hots) were typical. Just wondering for my own personal knowledge, what would be some things that my cause this condition?
Appreciate the info.

 

[charlie b]

Did you intend to attach a photo?

 

[480sparky]

105?F or 105?C?

 

[marcram]

I wanted to attach a photo but there are no options to do so on my panel. It was 105 F.

 

[charlie b]

When you hit the Reply button, do you see a "Manage Attachments" button below the bix into which you type your reply? That is how you post a photo.

 

[GeorgeB]

The hottest conductor in the pic is the neutral coming from the main panel, it was over 105 degrees when shot individually. It was hot only at the terminal. The other two conductors, (the hots) were typical. Just wondering for my own personal knowledge, what would be some things that my cause this condition?

NORMALLY, heat is caused by current flow through a resistance. Assuming that to be the case, for one terminal to be a higher temperature than another suggests (in order of likelihood to me) a loose screw, a stripped screw, a bad terminal, or wrong size wire. If this is a 120/240 single phase panel, the "neutral" cannot have higher current than the "hots"; indeed, normally it will be the difference in the current of the 2 "hots".

105F is not, in and of itself, too warm; the terminals will be at least 140F (60C) rated, most likely 75C. I'd recommend that the owner have an electrician check it out, but if I were buying, that small a difference would not be of sufficient concern to prevent my purchase unless there was overheating evidence such as discoloration or melted insulation. You might have tested at a low current time. I would get it looked at afterwards.

I'm an engineer, not an electrician.

 

[480sparky]

How to post images.

 

[marcram]

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I hope this works...

 

[iwire]

Without taking current mesuarments there is little vlaue in just the IR image.

Yes, the condutor is hotter than the others, that is about all that we can say.

You say it is 105F well that is not bad at all in most cases and do you really know that it is 105?

Did you take the time to set up your reflectivity and emissivity settings correctly for that shot?

 

[480sparky]

I'm far from being an IR expert, but I don't see anything 105?F in the image.

If it is, why is 105 'too hot'? Will it start a fire? Melt the insulation? Is the southern US (from Miss to Tex) in trouble today because it's going to get that hot there?

 

[ELA]

I would agree that 105F in and of itself it not much to be concerned about.
When you do a comparative analysis however it seems to warrant having someone try to tighten the neutral.

 

[wptski]

I'm far from being an IR expert, but I don't see anything 105?F in the image.

If it is, why is 105 'too hot'? Will it start a fire? Melt the insulation? Is the southern US (from Miss to Tex) in trouble today because it's going to get that hot there?

How about in this one?

 

[480sparky]

How about in this one?

I see no problems whatsoever.

First, because I have no idea what I'm looking at. Second, 491.0 what? For all I know, it could be Rankine.






Heh heh, you're gonna convert that, aren't you?

 

[brentk]

As a fellow thermographer with an electrical background it appears to me to be a loose neutral connection. From my interpretation of the photo the actual connection itself is hot, but as you follow the wire further away from the connection the wire cools down. To me this would be a loose connection; if it were a load based situation the temperature would probably be warmer along the entire wire. As it has been stated 105F is not in itself that much concern, however i would recommend the connection be checked.

 

[wptski]

I see no problems whatsoever.

First, because I have no idea what I'm looking at. Second, 491.0 what? For all I know, it could be Rankine.

Heh heh, you're gonna convert that, aren't you?

It's in F. A Klixon overload on a dehumidifier compressor that was dropping 3.2V across it at about 4.5A. The contact where the pigtail was spot welded developed a high resistance causing the OL to open/close every few minutes.

 

[KentAT]

By comparison to the other conductors, that terminal has something going on and should be checked.

Little problems grow up to be bigger problems.

Here is a loose wire I found on a light switch in our office. Switch was slightly warmer to the touch then the other one, so I checked it.

Camera shows not too bad at 70 degF, but would anyone really say "naw, I won't tighten it until it shows over xx degF?"

 

[LarryFine]

I want a camera like that!

What's a decent (cheap) one cost?

 

[wptski]

By comparison to the other conductors, that terminal has something going on and should be checked.

Little problems grow up to be bigger problems.

Here is a loose wire I found on a light switch in our office. Switch was slightly warmer to the touch then the other one, so I checked it.

Camera shows not too bad at 70 degF, but would anyone really say "naw, I won't tighten it until it shows over xx degF?"

What was it like after tightening the screw? Try checking voltage drops across a simple light switch and you'll be surprised!

 

[480sparky]

...........what's a decent (cheap) one cost?

$3k.

 

[marcram]

As a fellow thermographer with an electrical background it appears to me to be a loose neutral connection. From my interpretation of the photo the actual connection itself is hot, but as you follow the wire further away from the connection the wire cools down. To me this would be a loose connection; if it were a load based situation the temperature would probably be warmer along the entire wire. As it has been stated 105F is not in itself that much concern, however i would recommend the connection be checked.

I dont have your electrical background (wish I did) but I suspected a loose connection also, from past scans.
If I may ask a stupid question; Why would the neutral be hot, I thought the neutral didnt carry current.
I do appreciate your time and input, thanks.