it's Friday, I'm Bored

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brian john

Senior Member
Location
Kilmarnock, Va
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Retired after 52 years in the trade.
Reviewing some old IR pictures and some NEC violations I had sent to an NEC Instructor.

A 3000 amp ( If I remember correctly) parallel feeder, one conductor of C phase was not routed with the other conductors.
InductiveheatingParallelFeedersRT.jpg


InductiveheatingParallelFeedersIR.jpg


The IR issue was a loose line side termination connection on CB 7, but the dust makes this interesting

DUSTGALORE-1.jpg


Busway splice bolts not properly torqued, these have the break off heads so a torque wrench is not required/

BUSIRRT-1.jpg


BUSIRIR-1.jpg


Bolted Pressure Switch not fully engaged.

BoltedPressureSwitchnotfullyengaged.jpg
 
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I may have posted some of these before?

Each phase has it own nipple, which simplifies installation

CTInductance-1.jpg


Mis-wired or defective CT's or the mis-wiring lead to defective CTs.

BADCTs-1.jpg


Just a bad "B" phase line side fuse clip.

BPhaseLinerSideBadFuseClip.jpg


Did not need an IR camera to spot this issue.

Untitled-8.jpg
 
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Self explanatory

Untitled-9.jpg


Parallel feeders with conductors seperated by a switchboard metal support

INDUCTION-1.jpg


1/2" washers stacked for a spacer.

NoGAP-1.jpg
 
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Brian I am always impressed by these pictures. That work is a whole new world to me but it is great to see what lies hidden underneath.
 
Bored? On a Friday? How can it be? Don't you know it is POETS Day?

(i.e., Phooey On Everything, Tomorrow's Saturday)
 
Great pictures, thanks for sharing.

I wish we had the training and setup to do thermal imaging. My boss is trying to push the owner into getting setup for it. We do quite a bit of ag/industrial, I bet we could prevent more than a few problems...

If we got one, I'd probably run around like a little kid with a new toy taking pics of everything...:)
 
Real great pictures, and real great learning experience.
However it seems to me that in all the cases the temperature was well within (and/or way below) the wire/terminals ratings.
Funny thing about wire ratings is, when they say it's 100A at 90deg C it also mean it'll get 90 deg C hot when 100A run through it.
On the first picture I can't really make out the other C phase conductors, but (if I'm correct) they're close to same heat as the most obvious one.
On the other ones it might be just the phase drawing more than the others.
On the busses, again, they seem to be way below their 75deg C ratings.
Lastly, the disconnect seem to be pushing the limit on the B phase.

brian john said:
Reviewing some old IR pictures and some NEC violations I had sent to an NEC Instructor.
Click to expand...
 
Strife,

All of the IR pictures except 2 are thermal issues resulting from wiring problems.

CTs with issues are ALWAYS a major concern.

A bolted pressure switch not fully closed may not open when required.

Balanced current sharing on parallel feeders is also important.

Plus as heat increases so does resistance and this can lead to major issues. Our intent to to prevent these issues.

If we were to pass over something at a low temperature that calculates out to a class 3 (minor issue) and ignore it, how would we look when it escalates to a class 1 or a system failure.

IR is predictive maintenance. The better you can predict possible issues, the less likely hood you/we end up with egg on our face.
 
charlie b said:
Bored? On a Friday? How can it be? Don't you know it is POETS Day?

(i.e., Phooey On Everything, Tomorrow's Saturday)
Click to expand...

"POETS" Day?? Have heard it said another way, but to maintain a "G" rating it shall remain unsaid...


To the OP, thanks for posting the pics.
 
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