240 Volt Nameplate Equipment fed at 480V

[Drisco]

Hey, i was out at a job site and I noticed a Federal Pacific distribution panelboard with a nameplate voltage rating of 240V. This is service equipment, MLO with 6 feeder breakers being supplied. The utility service feeding this equipment is 480/277V secondary 3ph- 4w. So this automatically rose a red flag in my mind and I reported it to the owner's representative with the recommendation that it be immediately replaced with 480V or 600V rated equipment.

Question is this: This panel looks as though it has been installed and operating at 480V for several decades. Is the nameplate rating correct? Or did FP just make all of their distribution type panels to handle 480V whether they are labeled 240V or not? What's the chance of this thing causing an issue?

Thanks,
Drisco.

 

[templdl]

Yes, It's wrong. What are the breakers rated at? Check the breaker ratings. Even though the breakers are rated for 480v the chassis may not be rated for 480v.
This is not intended to give the panel a pass but the pnlbd mfg may make the 240v the same as the 480v pnlbds. I know that the mfg that I once worked for added insulating sleeve similar to shrink tubing over the bus connectors to the breakers otherwise the 240v were the same as the 480v pnls.
But, if what you are saying is correct then no matter how it is spun it is incorrect.

 

[ptonsparky]

We see 240v pump panels, fused disconnects, etc being used at 480 often enough. Not right, just is what it is. Some have been in for years.

I should clarify that the pump panels were farm or field engineered.

 

[zxfabb]

Normally the mechanical structures and busbars are the same for panel rated 240V or 480V. You have to check the ratings of electrical components. The SCCR of circuit breaker, which significantly varies at 240V and 480V, must not less than available fault current. Anyway, the label is wrong in this case.

 

[zog]

Drisco, what is the panelbpard type?