firstly the ac should have been original .. secondly if alternate must be fitted then it should be atleast of a 1000cc car .. like for passo kabli ac of duet is recommended instead of 660cc (mostly they fit mini pajero ac) .. when u replaced condenser was it bigger in size then ur gas pressure would have varied, if gas is filled to pressure, then load on compressor has increased with more gas in the system
newer model cars cut down or shut down ac when car is accelerated or engine temp goes bit on higher side .. then there is a manual thermostat behind the glove box in some car to give a max cutoff value .. sometimes this adjustable knob is disturbed