high suction pressure

[apandi]

Hello,

I'm doing commisioining duct-split unit (DX system),
detailed outdoor-unit with a scroll compressor copeland ZR72KC-TFD (I max 12A)
R407C charge, indoor-unit with cooling coil capacity 14.3kw with danfoss expansion
TGEX-6TR-20kw (P.N.067N2236)
T room control setting at 24C.

after vacuumizing and charging R407C, start-up and running the unit,
after 12 hours running,
T room is still too high at 25-27C
Suction pressure = 80PSiG and liquid pressure = 270 PSiG
the compressor I run = 8 Ampere
what's about wrong with this unit??

I'm confused why the suction pressure can be high (80 psig)
My last bit of waste refrigerant (from liquid line), and then
pressure turns into P suct = 80PsiG P liquid = 255 psig

Please opinion or input to have experienced the above case.

[Gary]

Evaporator air in temperature = ?
Evaporator air out temperature = ?
Low side saturation temperature = ?
Suction line temperature = ?

Condenser air in temperature = ?
Condenser air out temperature = ?
High side saturation temperature = ?
Liquid line temperature = ?

[Brian_UK]

High load on system or unit undersized plus we need all the information that Gary detailed.

[apandi]

Garry and Brian,

Noted.
Thank you for the advice

[Gideon Beddows]

Hello,

I'm doing commisioining duct-split unit (DX system),
detailed outdoor-unit with a scroll compressor copeland ZR72KC-TFD (I max 12A)
R407C charge, indoor-unit with cooling coil capacity 14.3kw with danfoss expansion
TGEX-6TR-20kw (P.N.067N2236)
T room control setting at 24C.

after vacuumizing and charging R407C, start-up and running the unit,
after 12 hours running,
T room is still too high at 25-27C
Suction pressure = 80PSiG and liquid pressure = 270 PSiG
the compressor I run = 8 Ampere
what's about wrong with this unit??

I'm confused why the suction pressure can be high (80 psig)
My last bit of waste refrigerant (from liquid line), and then
pressure turns into P suct = 80PsiG P liquid = 255 psig

Please opinion or input to have experienced the above case.

A suction pressure of 80 psi isn't unremarkable with an air on of 27C? Set the head pressure controller to maintain 265 psi and add gas until the liquid line measure about 35 C, this will give you 9K subcooling and you shouldn't be far wrong at this point. When the room temp gets to 22 then check your superheat and adjust as required. 4 - 10 will probably be ok for most applications?

This is the best I can come up with with the info at hand?

[Magoo]

Did you liquid charge the system.