Temperature of Lugs
Temperature of Lugs
(OP)
Is ther a formula for determining what the temperature of the lugs on the load side of a main breaker should be?
Thanks
Thanks
When was the last time you drove down the highway without seeing a commercial truck hauling goods?
Download nowINTELLIGENT WORK FORUMS
FOR ENGINEERING PROFESSIONALS Come Join Us!Are you an
Engineering professional? Join Eng-Tips Forums!
*Eng-Tips's functionality depends on members receiving e-mail. By joining you are opting in to receive e-mail. Posting GuidelinesJobs |
|
RE: Temperature of Lugs
RE: Temperature of Lugs
For ANSI regions, a genaral rule is 99 NEC 110-14 is unless marked otherwise, 100 ampere or less terminations are rated 60°C; above 100 amperes—75°C.
RE: Temperature of Lugs
RE: Temperature of Lugs
RE: Temperature of Lugs
RE: Temperature of Lugs
lugs should always run "cooler" than the conductor.
If a lug is at the same temperature or a higher temperature then a failure is bound to occur.
RE: Temperature of Lugs
http://www.bussman.com/library/docs/spd02/SPDSection04.pdf
RE: Temperature of Lugs
Depending on the circuit breaker terminal thermal rating, the corresponding cable lug thermal rating should be used.
RE: Temperature of Lugs
The limiting factor on cables and therefore on the lugs attached thereto is the maximum insulation temperature, which determines the maximum conductor operating temperature (eg 90C for XLPE/EPR, 70C for PVC).
If there is a loose / poor connection somewhere (ie a badly crimped connection or a loose bolt) the the lug and cable will become much hotter due to I2R losses, this will cause the temperature to spiral upwards with a danger of fire.
_______________________________________
Regards -
Colin J Flatters
Consulting Engineer & Project Manager