Opening a disconnect in the closed position
- Thread starter jbolen
- Start date
- Status
- Location
- Illinois
- Occupation
- retired electrician
That is not in the NEC. It may be in the product standard, but I am not sure.
qcroanoke
Sometimes I don't know if I'm the boxer or the bag
- Location
- Roanoke, VA.
- Occupation
- Sorta retired........
As Don said it's not in the code forbidding it.
I know at one time you could open them in the closed position by turning a screw on the side that over rode the door locks and would let you open it in the closed position.
I don't think you can do that now. May be a UL thing or OSHA thing.
- Location
- San Francisco Bay Area, CA, USA
- Occupation
- Electrical Engineer
NFPA 79 (the standard for industrial machine controls) requires that doors be interlocked with a disconnecting device so that you cannot enter an enclosure without first killing power and any defeater mechanism requires a tool to operate, implying that whomever defeats it is a "qualified worker" in a facility.
The NEC has few requirements for this in Low Voltage, hence the existence of fused pull-outs as disconnect devices. But there are a few exceptions; bus duct disconnects (368.239), and Medium Voltage equipment MUST be interlocked.
The NEC has few requirements for this in Low Voltage, hence the existence of fused pull-outs as disconnect devices. But there are a few exceptions; bus duct disconnects (368.239), and Medium Voltage equipment MUST be interlocked.
Last edited:
- Status