fused vs. non-fused disconnects
- Thread starter denny
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BAHTAH
Senior Member
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- United States
Re: fused vs. non-fused disconnects
Denny, if the branch circuit overcurrent protection supplying the unit meets the requirements for protection then you can use a non-fused disconnect. Example would be if you have fusible distribution feeding the HVAC unit and the unit called for fuse protection there would be no reason to have fuses protecting fuses on the same circuit so you would install a non-fused disconnect at the unit.
Denny, if the branch circuit overcurrent protection supplying the unit meets the requirements for protection then you can use a non-fused disconnect. Example would be if you have fusible distribution feeding the HVAC unit and the unit called for fuse protection there would be no reason to have fuses protecting fuses on the same circuit so you would install a non-fused disconnect at the unit.
ron
Senior Member
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- New York, 40.7514,-73.9925
Re: fused vs. non-fused disconnects
Also double check the available short circuit current at the disconnects. If it will be more than 5000A (generally the withstand rating of a unfused switch), then use a fused switch even if the equipment nameplate doesn't require it.
Usually on a small unit, the small wire size leading to the unit will reduce the short circuit avaiable below 5KA.
Also double check the available short circuit current at the disconnects. If it will be more than 5000A (generally the withstand rating of a unfused switch), then use a fused switch even if the equipment nameplate doesn't require it.
Usually on a small unit, the small wire size leading to the unit will reduce the short circuit avaiable below 5KA.
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