The A/C will operate at any angle between right side up and upside down, Though there can be a few issues.. here is hot to prevent them (Upside down is not recommended by the way read on as to why)
As the air is cooled it gives up excess moisture, the air coming off the evaporator coils (Cold,indoor coils) is always nearly 100% humidity.. believe it or not, The excess water that it can no longer hold drips down into a drip tray under the evaporator coils. then runs back and out onto the roof.
On the Carrier Air V. the drip lip is in the rear.. The Advent Air, it's on the driver's side.
If the A/C is operated so the drip lip is HIGHTER than the front of the drip tray, Bad things happen. (It rains INSIDE your RV)
Upside down eventually water will build up in the cooling chamber, (Why it is not a good idea).
That is why when you see 'em on a 5-er roof at an angle it is usually Front high.
That said, the system operates normally no matter what the angle, it's only the disposal of the condensate that may be an issue and a very quick visual with the cover off will tell you what the danger "unlevel" is...Oh, while you have the cover off expose the condenser coils (hot outdoor coils) and clean them. Makes it work better.
Home was where I park it. but alas the.
2005 Damon Intruder 377 Alas declared a total loss
after a semi "nicked" it. Still have the radios
Kenwood TS-2000, ICOM ID-5100, ID-51A+2, ID-880 REF030C most times