help with extra charge.

[still learning]

good afternoon everyone .
the boss mans away at the moment and could do with some help with the extra charge calculation .
we have a Mitsubishi city multi , one ten port bc box and 9 indoor units .
the out door is a pury-p200ylm-a1
410a with a factory charge of 9.5 kg
my pipe to bc box is 3/4 and 5/8 28.3 meters
and a total indoor unit pipe length of 102.9 m of 1/2 1/4 .
cheers for your help .
i did have a glance at the install manual , and frankly it is as clear as mud .
my fault for mucking about at school i guess .

[Tayters]

Been a while but had a look at a manual for YJM and it goes:

High pressure pipe from outdoor to BC (i.e small pipe only) 28.3 x 0.11 = 3.113kg
Liquid line from BC to units (take it that's the 1/4" only) 102.9 x 0.024 = 2.4696kg
P200 + BC = 2.0kg
Total capacity of indoor unit (say yours totals 200) 3.0kg

Round the total figure up, not down to 1 decimal place then check extra charge is less then the spec (24.8Kg)

From a Dutch manual for YJM had slightly different values for the outdoor but the jist is the same.

I'm sure there are some more experienced than me but from think that should get you going. Did see a Mitsi spreadsheet for commissioning once. Spaces for lengths, sizes, addresses, took all the fun out ha ha.

Cheers,
Andy.

[still learning]

Cheers for the help taters.
ive got my head round this now.
going to need a holiday soon before the head pops.