Thermal imaging what do you guys think of this picture

[ritchiehulse]

Hi all,

A company had some minor problems with a bussbar fitted, all got renewed and working completely fine but as a precaution they wanted a test on the bars (IR,Zs etc)
whilst i was there i used our thermal imaging camera on the joints just to check no loose connections etc and i noticed they had a UPS connected to the bars incase they lost power, felt the cable which felt hot to touch


Now i know 33.6 deg is well within 90 deg but it hit me as strange how this is the only swa in the building getting anywhere over 21 deg. Is this something that's worth looking into or is it just because its the batteries constantly being charged? I wanted to put the clamp on ampmeter but without shutting it down there is nothing to clamp it onto

 

[HandySparks]

Can't quite picture why you can't clamp the SWA cores. How are they connected to the busbar?

 

[ritchiehulse]

I cant clamp the cores atm without shutting down the backup (means turning off a isolater at either end before access to the cables can be obtained),,,,this can be arranged im just making sure its necessary before doing so.

 

[westward10]

I have found thermal imaging to be very deceptive, it can very often show a "hot spot" when in fact it isn't.

 

[ritchiehulse]

Yes i agree it can be a usefull tool but also make you worry over nothing, but its not often a grab a swa in a cold room and feel it very hot,
They a bussbars in a riser cupboard, which the higher you went the warmer the bars were getting, once i got to the top floor and found the backup it was obvious it was this that was making them warmer, not saying its wrong it just made me want a second opinion as to what other people would do

 

[westward10]

What size is the cable and its protective device.

 

[ritchiehulse]

its a 150mm with separate earth, i believe they were on 120a fuses 3phase,

 

[westward10]

120A fuses are odd but you could have some harmonic effects going on with the ups.

 

[SparkyChick]

If it's a sizeable UPS (sounds like), I'd be very surprised if it doesn't have some means of establishing the output current on the various phases. Maybe a chat with their facilities peoples could get you some historical data (or at the very least, some instantaneous readings).

 

[Marvo]

33.6 degrees is so far away from the allowable limit I wouldn't even investigate normally unless something struck me as hinky. The thermographic image is alarmist, it makes it look like the wire is glowing white hot whilst in fact the midday ambient temperature where I am is higher than that most days

 

[Rpa07]

The thermographic image is alarmist, it makes it look like the wire is glowing white hot whilst in fact the midday ambient temperature where I am is higher than that most days

Alright @Marvo, don't rub it in! It was a lovely Sping 6 degrees C today with the sun out - not at all uncomfortable!

 

[Marvo]

Lol, I don't envy you, at 6 degrees everything would be the same shade of deep purple in a thermal image.

 

[mydigitalhome]

Put some black electrical tape on all the bits you want to test and see if that changes result. As sometimes it's the reflectance of the image giving dodgy readings.