The subject of how to size a disconnect switch encompasses a wide range of important elements. Disconnect switch sizing | Information by Electrical Professionals for .... I have fused disconnect on the primary side of the transformer. I can size the fuse but cannot find information on sizing the disconnect switch.
So i guess my general question is: how do you size disconnect switches? Help would be appreciated! It's important to note that, thanks That is about 50 amps, so you would need a 60 amp fused disconnect, The next size up is 100. Sizing Disconnects for motors | Information by Electrical Professionals ....
When sizing a disconnect for a motor do you use the Table amps in the code or do you use the nameplate. I have a 20HP 3Phase motor at 240V. The table Amps is 54A. Can you go down to a 60A or go up to a 100A Nonfusible disconnect General duty safety switch. UL508a Disconnect Sizing Calculations | Information by Electrical ....
I am trying to size a main panel disconnect and have come up with a few different numbers here and was hoping to gain some clarity on here. From the UL508a documentation: 30.2.2 A molded-case switch, a switch unit, a fused power circuit switch, a pullout switch, and an open... Can I size the disconnect switch based the name plat of the motor X S.F. This perspective suggests that, (325A X 1.15 = 374A- which means I can use 400A HD Disc sw) or it needs to be rated for the motor HP, whch means I have to use 600A since the 400A disc is only rated at 250 HP? Can I use the FLA name plate (325A) for sizing or I must use the NEC FLA (361A) Thank you,
Disconnect Size | Information by Electrical Professionals for .... Another key aspect involves, what's the purpose to put such an oversized disconnect switch? If it's show #12's on the load side of the 100A disco could the line side but much larger? Equally important, it only tells me to connect to existing? Don't confuse disconnect with overcurrent protective device . You can have a 100 amp disco and inside have a 15 amp breaker.
You need the rated load current or branch circuit selection current to properly size the disconnect, though either the MCA or MOCP for a single compressor would be larger the required disconnect ampere rating. From another angle, explain the AS/AF, AT/AF sizes | Information by Electrical .... Not all mfrs are the same, that’s why. AS/AF for fused switches means Amp Switch /Amp Fuse. So for example 600AS/500AF means you have a 600A rated switch holding a 500A rated fuse. The switches come in only a certain number of switch sizes; typical for North America (NEMA KS-1 design specs) is 30, 60, 100, 200, 400, 600, 800, 1200, 1600, but not all mfrs offer all of those sizes, especially ...
Proper disconnect size?
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