The car is a Vauxhall Agila A and the compressor is a Delphi CVC internally controlled compressor, so it's basically supposed to never cycle while the AC is on. The transmission is obviously manual (very low end European car). The car has a Bosch Motronic ME ECU. The car hasn't got a rpm indicator.
Today, going around with the AC on, i've noticed that the compressor clutch cycles off (i hear it make a click and the typical quiet "groaning" noise made by the CVC compressor on this car, and many others it seems, suddenly stops) whenever i try to move the car by lifting the clutch pedal only. It won't do that when i rev it from stationary (so that i think i can rule out AC system pressure/charge issues), it never cycles while idling or driving, and it doesn't seem to cycle whenever i use both the throttle pedal and the clutch one at the same time. It then immediately re-engages as soon as the RPMs start increasing again.
It looks as if the ECU is programmed to disengage the clutch automatically whenever the engine RPMs lower too much, but i never found anything like this in any documentation about automotive ac systems i read so far. On the other hand, i've read that the clutch usually gets disengaged temporarily whenever a strong acceleration is desired.
Are ECUs supposed to behave that way (maybe a way of preventing the engine from stalling when the AC is on), so that what i experience is perfectly normal AC compressor clutch behaviour, or have i got a problem (bad AC compressor relay, clutch coil on the way out, alternator/battery problems even if the battery warning light never comes on)?
I know that too much compressor clutch cycling can ruin the friction surfaces in the clutch assembly, that's why i want it to be limited to the strict necessary.
Thanks for reading and for any help.