Time Consuming

[Arc]

Working on a Hitachi multisplit system with a scroll compressor, normally holds 9kg of R407c and requires an additional 8kgs totalling 17kgs. Have charged one of these systems before bombing high side with liquid until no more will enter, then running the system and slowly feeding liquid into low side. My problem is it takes forever and initially cuts out thermal protection. Does anyone have a better method or recommend an instrument etc?

[sedgy]

hi ark, can you pump the system down?

[bigor_2]

sedgy good idea

Arc see function PUMP DOWN in service manual and return refrigerant into outdoor unit. Then vacuuming and
add missing quantity of refrigerant in liquid pipe. Do not forget to close service valves on the outdoor unit after PUMP DOWN

[bigor_2]

Arc That henceforth such was not, it is necessary to heat a cylinder

[Gingerair]

134a in cold weather with cold bottles is worst...
Use a reclaim unit to pump any extra charge into liquid line..

[Brian_UK]

Connect your reclaim machine in push/pull mode and push the liquid into the system.

[bigor_2]

Arc Forget that I wrote.
Reclaim machine use is a civilised way.

[Arc]

Pumping the system down is a good idea. Would like to throw the cylinder in a bottle of hot water but my bottles have to be inverted for liquid.
Was going to pump it in with my reclaim but slightly reluctant about contamination. The gas I pulled from it was acidic, not sure if a drier on the end of it would do job?
Also I seem to lose 200-300gms in the machine but this could be allowed for.
I even called Mastercool who manufacture my recovery unit but there technical crew could not recommend/comment on it?