PhillipPretorius
New User
- Location
- Netherlands
- Occupation
- Design engineer
We have a machine with 2 electrical cabinets, one on either side of the machine. The electrical panels need to comply with UL508A, and the machine with NFPA79.
The second cabinet derives 2 x 480V feeds from the first cabinet (one feed is for motor circuits via a disconnect switch on the 1st cabinet, and the second feed is for a power supply for the control circuits).
I was told that because the 2 cabinets are not in sight of each other as they are on opposite sides of the machine and not within 15m of each other, that we need to have 2 x disconnect switches on the 2nd cabinet (one for for each 480V feed into the cabinet) in order to comply with UL508A, sect 66.6.1.
My argument is that the 2nd cabinet is fed from the 1st cabinet where the client power supply is fed into.
The 1st (main cabinet) has a mains disconnect switch (interlocked with the panel door per the requirements of UL508A).
It is thus not a seperate supply into the 2nd cabinet, but a feed with circuit breaker protection from within the first cabinet, but UL seems to see it as seperate supplies into the 2nd cabinet, requiring seperate disconnect switches. Does anyone have any advice on this?
The second cabinet derives 2 x 480V feeds from the first cabinet (one feed is for motor circuits via a disconnect switch on the 1st cabinet, and the second feed is for a power supply for the control circuits).
I was told that because the 2 cabinets are not in sight of each other as they are on opposite sides of the machine and not within 15m of each other, that we need to have 2 x disconnect switches on the 2nd cabinet (one for for each 480V feed into the cabinet) in order to comply with UL508A, sect 66.6.1.
My argument is that the 2nd cabinet is fed from the 1st cabinet where the client power supply is fed into.
The 1st (main cabinet) has a mains disconnect switch (interlocked with the panel door per the requirements of UL508A).
It is thus not a seperate supply into the 2nd cabinet, but a feed with circuit breaker protection from within the first cabinet, but UL seems to see it as seperate supplies into the 2nd cabinet, requiring seperate disconnect switches. Does anyone have any advice on this?