Hi All, For some time now we have had two Grasso duo packs fitted to a new freezer plant. But now we have been tould that we should not charge oil into the suction line when adding oil with the compressors running. Have read the Grasso manual and can not find anything about charging oil to maintan the oil level. Sent an e-mail to Grasso UK but they seem not too want to pass on any infomation to us only to the GEA engineers in there group. So if you have any of the Grasso duo packs how do you top up the oil level ? please.