carrier split 410a

[blueduck]

hello everyone, I'm working on a new install we installed (2)4ton and (1) 5ton A/C units with new furnaces and duct work. All the units are doing the same thing so I just posted the 5 ton.... On day 1 I thought I had an air flow problem so I got a dwyer manometer to measure external static pressure. I got neg.08 in the return and pos.1 in the supply (using a probe) add the two together and get .18 Furnace spec. cfm on chart .2 on hi speed is 2175cfm so that looked OK. I have never used one of these before so did I do that correctly?
I decided to remove some gas because the superheat was so low but this does not seem right because I measured the line set and added 5oz planning to add 1oz more. On day 2(today) the book called for 12f superheat so I pulled out 10oz to get 12f. Should my evap temp be that low? what am I missing? I never get to work on an AC unit with the building this cold so I'm not sure what to think. Thanks.

carrier cond. 38ezg060500
evap ck5bxa060024aaaa
carrier furnace 58mxa 100-20
10 feet extra line set added 5oz 410a
day1
outside air 82db 65wb cond.TD 20f
evap air 76db 65wb TD 21f
SL temp@cond. 38f
LL temp@cond. 92f at evap 89f
low side 112psi/38f superheat 0f
high side 320psi 98f
day2
removed 10oz 410a
outside air 77db
evap air 76db 61wb TD 10f
SL temp@cond. 45f
LL temp@cond. 88f at evap 85f
low side 100psi/33f superheat 12f (book called for 12)
high side 300psi/96f

[rubobornot]

Those units are alot easier to charge correctly if you use the expansion valve kit. It attaches to the same fitting as the restrictor. The unit will perform alot better with the expansion valve and be more efficient.