Start cart running Packs A319/320
A319/320.
Occasionally we defer APU bleed air or the entire APU.
Obviously a start cart would be required in this instance. Is there any non published aircraft limitation/suggestions (min/max bleed pressure, time, single pack or two packs, intermittent use, etc.) using the start cart to run the packs? (running the pack/packs to cool the cabin while boarding)
Is anybody familiar with start carts - (general information only - there are probably a hundred variants) How long they can operate at high pressure? If it overheats how long is the cool down? Is there a lower pressure setting to run packs? Is it discouraged to run packs using a cart?
Thanks.