90 degrees termination
- Thread starter elecold
- Start date
- Status
- Location
- Massachusetts
Many terminals and lugs are rated 90 C if not more.
But the equipment they are found in such as breakers, panelboards, disconnect switches are not.
- Location
- Chapel Hill, NC
- Occupation
- Retired Electrical Contractor
The lugs may be rated 90C but generally the equipment itself is only rated75C
And the method depicted below shows what typically must occur to use a conductor at its 90°C-rated ampacity. Everything within the auxiliary terminal enclosure (i.e. "tap box enclosure" is incorrect terminology) is rated for operation at not less than 90°C.
The only area where I know you can "get away with" not using an auxiliary terminal enclosure is when the "transiition splice" is made inside the rails of cable tray.
The only area where I know you can "get away with" not using an auxiliary terminal enclosure is when the "transiition splice" is made inside the rails of cable tray.
Last edited:
Carultch
Senior Member
- Location
- Massachusetts
And the method depicted below shows what typically must occur to use a conductor at its 90°C-rated ampacity.
There are very few applications where I could see an advantage to doing this, as anywhere where the length is long enough for the benefit to justify the extra complexity, I probably have to curtail voltage drop anyway. But it still does exist in theory, and has some value for correcting a mistake to restore compliance.
The most common reason why one would care about the 90C column of the NEC, is the fact that we can use it for our conditions of use calculations, while using the raw ampacity value at 75C for terminations.
Carultch
Senior Member
- Location
- Massachusetts
Insulation piercing connectors
Split bolts
Butt splices
Polaris insulated taps & in-line splice/reducers
MC4 & Amphenol solar connectors
And that will remain the case... but there are some. :happyyes:
- Status