Please go back & read my post.
I mentioned that the unit most likely does not have LP bypass capabilities on the start of additional compressor or compressors within the same circuit.
Scanario: Cir. A starts compressor A1, the bypass timer provides contact closure accross the LP for 2 or 3 minutes, thus allowing the compressor to recover from the startup dip.
Cir. B starts compressor B1, the same temporary contact closure procedure takes place again just like it did on cir. A, but when compressor B2 or A2 start, there is no temporary contact closure therefore the cir. cannot recover from the dip in suction pressure.
Trying to correct a problem such as this with low ambient controls alone will often result in setting the operating head pressure range for the cond. fans very high, which will sorta solve the problem, sometimes, but failures will still happen & you will pay dearly on KW consumption.
Even on the newer models with intelligent control logic, this is a weak link for the reasons mentioned above.
If the unit is new, you might be able to get Trane to program a chip for you with this bypass feature in it for each time an additional compressor starts as opposed to only when the first compressor in a given circuit starts.
But I doubt it.
You can use a manual reset LP, this can be a little tricky to wire in sometimes because often the safety circuit is 24vac & the contacor circuit is 120vac.
If thats the case, you can add a few relays to the machine with delay on make timers.
You could use 90-381 type, wire the NC contacts to the pressure control & wire the coil to the contactors circuit with a delay timer in series that doesn't allow the relay to power for 2 or 3 minutes, therefore providing temporary contact closure ANYTIME a compressor starts.
If you have 4 compressors, you will need 4 relay & 4 timers.
I hope this is helpful.