If I build a panel that is inside an enclosure that has a 120V AC cord going into a circuit breaker, which then feeds into a power supply that changes 120V AC to 24V DC, which then is fed to a bunch of 24V modules that do really simple things like data acquisition and send it out over the network on Modbus TCP, does this box need a UL 508A field label from an NRTL or some other entity capable of making field evaluations?
Or if not UL 508A, is there some other UL standard it should be evaluated under?

 

jfenwick
Welcome to Control.Com!
1. Do you know the panel's S.C.C.R.?
2. Are all components in the panel UL listed, including the wires and/or cables?
3. Are you the only one that has access to the panel's interior?
4. Are wire terminals access able?
Even if you answer the above properly you will be held accountable for any injury sustained by others!
Regards, Phil Corso

 

... does this box need a UL 508A field label from an NRTL or some other entity capable of making field evaluations?
All States have adopted some version of NFPA 70 (NEC or National Electric Code), article 409.110 covers most of the marking requirements.

Or if not UL 508A, is there some other UL standard it should be evaluated under? Unlike the NEC, UL 508A has not been made a law in Virginia...your state may be different. And to Phil's point, OSHA is the final judge on what is safe.
V/R Gary Kvammen