IEEE C37.21
For IEEE C37.21, standard title is Control Switchboards; nrtl is UL; laboratory is UL LLC; status is currently recognized, recorded from its source on 2026-08-10.
- Test standard
- IEEE C37.21 verified
- Standard title
- Control Switchboards verified
- NRTL
- UL verified
- Laboratory
- UL LLC verified
- Status
- currently recognized our reading
Values marked our reading are our classification of what the source says — the source does not print them in those words. The quote below is the evidence for each one; judge it yourself.
What the source says
IEEE C37.21 | Control Switchboards |
— osha.gov, retrieved 2026-08-10
Source
- osha.govhttps://www.osha.gov/nationally-recognized-testing-laboratory-program/ul