New air con refill station smoky.

Hi there,
new to the forum.
I run a small garage and 3 days ago we got new aircon refill station.
ECK 1800.
we have done 2 cars yesterday and today my mate asked me to rechaerge his aircon.
I connected hoses etc. 2.8kg gas left but the computer tells me theres not enough to refill 525g.
Thats the first problem.
Ok sorted that then during vacuum after about 5 mins smoke start coming from compressor oil container.
At this stage i stoped the process.
Car Air con had a leak anyway as i checked on my old machine.

Any ideas?
Mike