Bus Duct

[Alwayslearningelec]

Has anyone come across this or done this before?? The retorqing that is? What exactly would be retorqed? And they are saying afgter it's been in service. THat means it must be shutdown??

All busway joints shall be accessible and torqued as recommended by the manufacturer. A
recheck of torque setting shall be made by this Contractor after the busway has been in service
and subjected to varying load conditions. This Contractor shall submit a report of this recheck
to the Director upon completion.

 

[ron]

We do not retorque anymore, but we remove the cover plates (if there are any) and check with an IR scan

 

[Alwayslearningelec]

We do not retorque anymore, but we remove the cover plates (if there are any) and check with an IR scan

Thanks. What does the IR scan do that it can replace retorqing?

 

[Alwayslearningelec]

Also can the IR scan be done live?

 

[ron]

Also can the IR scan be done live?

It must be done live, as the IR scan is looking at heat. If there is no current flowing, then there is no heat to look at.
Some will de-energize to remove covers, then heat it up, then do the scan. When scan is done, then de-energize to re-cover.

 

[Alwayslearningelec]

THanks so the IR has nothing to do with the retorqing? Or if you do the IR scan no need for retorqing and if so why?

 

[augie47]

AFIK, retorquing is normally done to eliminate loose connections. The IR scan will assist in identifying any loose connections that need to be addressed, An IR scan may eliminate and need to retorque.
Here is a decent read:

Infrared Electrical Inspection, Electrical Testing Finds Hot Connections - Albany, NY | Infrared Imaging Services

Infrared Imaging Services provides infrared electrical inspections, infrared testing and electrical surveys to detect system overloads, loose and defective components and damaged switch-gears with thermal imaging, as well other electrical testing and electrical surveys in Albany, NY, NY Capital...

www.infraredimagingservices.com

 

[infinity]

Has anyone come across this or done this before?? The retorqing that is? What exactly would be retorqed? And they are saying afgter it's been in service. THat means it must be shutdown??

No shutdown required. You can torque the cover plates on the coupling joints but the actual coupling fittings have shear heads on the bolts that break off when they're tightened. Unless recommended by the bus duct manufacturer IMO there is no reason to re-torque the couplings.

 

[Alwayslearningelec]

No shutdown required. You can torque the cover plates on the coupling joints but the actual coupling fittings have shear heads on the bolts that break off when they're tightened. Unless recommended by the bus duct manufacturer IMO there is no reason to re-torque the couplings.

Thanks

 

[ADub]

THanks so the IR has nothing to do with the retorqing? Or if you do the IR scan no need for retorqing and if so why?

An IR scan shows hot spots indicative of high/low resistance connections. If a joint under load shows up normal temperature wise it is assumed the connection is sound and there is no reason to put a wrench on it


Sent from my iPhone using Tapatalk

 

[Alwayslearningelec]

Here are a few photos. IR scans were done but they are not accepting that in lieu of retorqing.

Think this can still be retorqed live?

 

[infinity]

Here are a few photos. IR scans were done but they are not accepting that in lieu of retorqing.

Think this can still be retorqed live?

I would torque it while energized.

 

[Alwayslearningelec]

I would torque it while energized.

Thanks..arent those parts live that you need to touch when torquing ?

 

[augie47]

Got it torqued, boss !

 

[Alwayslearningelec]

Got it torqued, boss !

lmao

 

[jim dungar]

Thanks..arent those parts live that you need to touch when torquing ?

Not on most bus duct built in the last 40 years. Notice how they are all touching the same metal mounting surface.

 

[infinity]

Thanks..arent those parts live that you need to touch when torquing ?

No there are no live parts. Put a torque wrench on the nut ans turn. My bet would be that 99.9% of all connections are still good if they were properly torqued in the first place. If this bus duct has sheer head bolts that's a pretty good bet.