drumburg
Member
- Location
- Wisconsin, USA
I have posted about this topic before but I think I kept getting off topic with the types of disconnects available. Ultimately, I am looking for a standard that states whether I must have an enclosure interlock or not.
I have been through NFPA79 quite a bit and from that I'm convinced that an interlock is required on any enclosure that has a disconnect and 50Vac, 60Vdc, or greater. My main problem is that we have other equipment here that should be covered by NFPA79 that doesn't have any interlocks and I'm trying to wrap my head around how the manufacturer is getting around the requirement.
I understand that OSHA may not require NFPA79 specifically but it does require a manufacturer to use some NRTL standards, does it not?
Machines that I don't see having interlocks also may not have an enclosure. For example, we use portable (on wheels) pad printers to decorate the widgets we make. These have a 220Vac (or 480Vac) power cord coming in with a power switch but doesn't have a traditional enclosure. It is a self contained unit with bolted on panels. Using a screwdriver you can remove a panel and access anything inside. Does the fact that a screw driver is needed to access the live parts allow for no interlock?
I have been through NFPA79 quite a bit and from that I'm convinced that an interlock is required on any enclosure that has a disconnect and 50Vac, 60Vdc, or greater. My main problem is that we have other equipment here that should be covered by NFPA79 that doesn't have any interlocks and I'm trying to wrap my head around how the manufacturer is getting around the requirement.
I understand that OSHA may not require NFPA79 specifically but it does require a manufacturer to use some NRTL standards, does it not?
Machines that I don't see having interlocks also may not have an enclosure. For example, we use portable (on wheels) pad printers to decorate the widgets we make. These have a 220Vac (or 480Vac) power cord coming in with a power switch but doesn't have a traditional enclosure. It is a self contained unit with bolted on panels. Using a screwdriver you can remove a panel and access anything inside. Does the fact that a screw driver is needed to access the live parts allow for no interlock?