HP RATING
HP RATING
(OP)
How do fused disconnects get a Horsepower rating?
I have a squared fused disconnect (600V, 60A, c/w 60A fuses)...it has a rating of 30HP on the box from the manufacturer...
Any Idea...
Regards,
TULUM
I have a squared fused disconnect (600V, 60A, c/w 60A fuses)...it has a rating of 30HP on the box from the manufacturer...
Any Idea...
Regards,
TULUM





RE: HP RATING
respectfully
RE: HP RATING
So because the fuses (in this case AJT60) is time delay it better protects motor loads...not sure though how 30HP is the magic number?
Regards,
TULUM
RE: HP RATING
Unless the switch is rated at 100%, it will be suitable for 48 amps, continuous current, under CEC. That is probably insuficient for a 50 hp. motor, particularly when you add the extra 25% ampacity required for motor circuits..
I thought you were wondering how you could start a 30 hp. motor on a 60 amp switch. You can't with the normal fuses.
respectfully
RE: HP RATING
RE: HP RATING
The horsepower rating is defined differently for fused and non-fused disconnects.
For fused disconnects, it's the largest horsepower that can be started using standard fuses sized at the disconnect switch max current rating. There's a "standard" horsepower rating that applies to any type of fuse and a "maximum" horsepower that applies to time-delay fuses.
In the US, any disconnect sw used as a motor disconnect must be "horsepower rated", but I've never seen one that wasn't, so it doesn't seem to mean much in reality.
RE: HP RATING
I will look into th download
Regards,
TULUM
RE: HP RATING
Eng-Tips: Help for your job, not for your homework Read FAQ731-376
RE: HP RATING