Retorque of bolted electrical connections
Retorque of bolted electrical connections
(OP)
There seems to be two camps of thought on performing "retorque" of bolted electrical bus connections. One promotes regular retorquing of bolted connections while the other calls for repairs made to connections based only on the results of a thorough thermographic survey. I have also been led to understand that regular retorque can max out the elasticity of the fasteners and cause the joint to loose its clamping force. Who's more correct and what are the details?





RE: Retorque of bolted electrical connections
Run1on
RE: Retorque of bolted electrical connections
RE: Retorque of bolted electrical connections
Don(resqcapt19)
RE: Retorque of bolted electrical connections
RE: Retorque of bolted electrical connections
RE: Retorque of bolted electrical connections
For the 2% question, which I join.
Before committing a "constructive discharge" from my position of a hired thermographer, I was once questioned by the authoritative office forces of "how much energy a hotel is using, so we can do a sales pitch to the corporation telling them that thermography will help in saving a lot of money by eliminating waste of energy for heating connections throughout the whole chain". I told the sales pro (!) (and presumably an engineer), that any thoughtful maintenance professional will treat such treatise with disbelief, and maybe with suspicion. No 2% level was even mentioned during our exchange.
I stressed, that the "energy waste" is insignificant in relation to the total electrical power being used. Much more important, I continued, is to _prevent_ power disruption (which is a "saving" by itself, sort of) and damage to the system, even by an electric fire. I was pressed for giving the numbers nevertheless...
So I gave them the average number of installed kVA (transformers) in those hotels... thinking - will such argument fly ?
It does, as I hear.
I still think, that _finding_ a problem is much more important than, say, 100 W (assume) of heat being generated by a bad fuse clip, terminal or faulty disconnect hinge. Particularly for a fire pump - and this was a _real_ case of concern to me. Let's count: 10 faults will generate 1 (one) kW. An equivalent of 1 (one) facade illumination lamp... Nothing to talk about, even for a whole chain of hotels.
Much more important is to keep the lights on
for the hotel guests - and this is a reliability factor at play.
Or: infrared scan quality.
My estimation of that percentage is 0.2%,
based on the thermographic anomalies I am
usually finding. Accounting for all other
smaller and not found anomalies let's make it 0.5% .
Any dissenting voice ?
ja2taj@netscape.net