Tim,
Look inside the panels and either stamped into or stamped onto the back of the panels will be something which states which is up and which is down, and typically you will find something which states as shown in the photos below.
The panel which states "TOP" is, obviously, stating which way the panel enclosure is intended to be installed to be installed.
The panel which states LINE/LINE (with one upside down below the rightside up one) is indicating that the panel enclosure may be installed with either end up or down. Provided that the panelboard itself is securely fastened in place in the enclosure in the manner in which the manufacturer intended, then that panelboard is designed to have the feed come in at the top or at the bottom.
Some are designed and intended to be installed one way, others are designed and intended to be installed either end up.
In a panelboard which is properly installed in an enclosure which is permitted to be installed either end up, and if the panelboard is not 'centered' vertically in the enclosure, then when the cover is installed, the cover may need to be installed 'upsidedown', which would make the circuit numbers upsidedown too. However, the circuit numbers are just there to identify the breaker to the label which identifies 'what the breaker is for'.
I have seen a few which I could accurately report as being installed "upsidedown', however, most/many do not have an 'up' or a 'down' ... 'installed horizontally' with the breakers operating vertically - absolutely incorrect ... 'installed with the back against a ceiling' - also absolutely incorrect (I have seen many of these) ... installed with the back against a floor or cabinet' - also absolutely incorrect (I have only seen this done once or twice).
Panel UP-DOWN 02.jpg
Panel UP-DOWN 01.jpg
Posted: Wed Jun 28, 2017 7:10 pm