Panel Board and Transformer Working Clearances

[JBUDA54]

I have seen several installations that the contractor installs a dry type transformer above the associated panel to maximum the space in the electrical room. I was confronted by a Vendor who sold Unitized Power Centers that had a Panelboad and Xfmr in an enclosure that looks more like an MCC. The Vendor stated that the transformer mounted above the panel is in violation on the NEC. I can not find anywhere in the code that states that installing the transformer above is in violation. Is this a case where the slaesman is blowing smoke or does he have a valid argument. I have been in this business for 12 years and have seen many electrical rooms set up with the transformers above the panel. Any advice to this is greatly appreciated

 

[dpc]

See Article 110. It depends on the relative depth of the transformer compared to the panelboard. Above 6.5 feet (AFF), it's not a problem. Below that, the depth of the transformer cannot be more than 6" greater than the panelboard.

At least the last time I checked..