voltage labeling - OEM's

Hey guys,

This is not really PLC related but a lot of you probably work for OEM's so I wanted to get your opinion on what you guys do for this. When building a new control cabinet for a machine what voltage labeling is required ( OSHA ANSI etc.) for the outside cabinet doors. This came up because we have a control cabinet fed from +24vdc however, inside the cabinet there is a display board with 360v for the inverter section. This is buried behind some other circuit boards. Do you need to label the outside of the cabinet with the highest level of voltage present or just what the incoming supply is and then put a genaric high voltage label on it. In our situation there is a genaric label only probably because of the low voltage supply. Please advise how you gusy label. Thanks

I think labeling equipment for the just "high voltage" is a waste of time and money. If panels are labeled for voltage at least I can tell which panel has the 440 power and which has lighting. On a piece of equipment it is a complete waste - as a maintenance electrician I pay them no mind since they do not tell me anything I do not already know.

What I would find valuable is a listing on equipment especially so if multiple power
fed from "panel xxx 3 ph 450"
panel zzz 250 VDC
This would be helpful to me, complies with OSHA multiple power labeling requirement. I realize equipment mfr would have hard time putting power supply location on when he does not even know maybe who end user is.

I am not sure if it is really required by OSHA but the arc flash value for equipment would be handy also - or at least would satisfy the liability burokrat gang.

Dan Bentler

The way I interpret the standard you only need to display the supply voltgae. If you have additional hazards inside the cabinet I think those should be identified individually inside the cabinet.

This would be similar to an AC drive. While it is supplied with a 480 VAC input the internal DC bus may go to 800 VDC or higher during regen before many drives will give up on overvoltage. Do you label the cabinet for this voltage level? I don't.

Keith