It is possible the compressor is overheating due to low refrigerant. Gauges and amprobe would confirm. If the compressor seems to be running longer than normal, that would confirm it.
If you cool the compressor with a portable fan and it no longer fails to start, that would confirm low refrigerant, or a bad compressor/clogged condenser. A partially clogged capillary would do the same thing, but the compressor current would be lower than normal.