cool#9
06-02-2010, 04:28 PM
Hi to all.
Well i've boring problem with a system consisting of 1 REYQ24M7(REYQ10M7+REYQ14M7) with 17 indoor unit and 17 BSVQ_M.
That was commissionned in 2003 and everything was right until december 2009:
Usually the whole system is under auto or heat mode in winter (so actually) for 16 units and on cooling only for one small computer room
( also supply by a BSVQ but in straight cooling: 19°C set point, managed by an itc DCS601B51).
The computer room unit is a FXMQ32M with a poor cooling efficiency like TH0=25° / TH1=27°c / TH3=4°C and TH4=23°C in normal state.
While using the whole system in cooling mode this is much better like TH0=22°C / TH1=23°C / TH3=6°C and TH4=13°C, and the room is cooling down.
I've already check the following:
Refrigerant charge is right based upon a complete recovery.
The unit is not at the end of the refrigerant pipe.
The version of the outdoor sofware is v785, i upgraded it 3 years ago (for another reason) on both master and slave unit.
The outdoors units were checked by service checker and there's not stepping down control neither retry loops.
I've check hot gas valve outside there's no hot gas bypass (this problem is well known on this series).
I've fully open the indoor EEV and the superheat is still high (23°C) while the 16 other indoors are on heating mode, for example.
I've changed the computer unit in heating mode 30mn and check the 3 way valve action in the BS box and that was right.
I've also try to shut some EEV (on 5 units in heating mode) in the nearest area...hoping i will recovery some refrigerant but in vain.
At last i've tried to put some units in cooling mode (also in the nearest area) and the problem occurs like the computer room (high superheat)
The only way to get a good efficiency is to set the whole system in cooling mode, like in summer, but it's not possible right now.
I do not understand why the system ran well during a couple of years and maybe a dear RE member could help to go ahead.
Kind regards
cool#9
Well i've boring problem with a system consisting of 1 REYQ24M7(REYQ10M7+REYQ14M7) with 17 indoor unit and 17 BSVQ_M.
That was commissionned in 2003 and everything was right until december 2009:
Usually the whole system is under auto or heat mode in winter (so actually) for 16 units and on cooling only for one small computer room
( also supply by a BSVQ but in straight cooling: 19°C set point, managed by an itc DCS601B51).
The computer room unit is a FXMQ32M with a poor cooling efficiency like TH0=25° / TH1=27°c / TH3=4°C and TH4=23°C in normal state.
While using the whole system in cooling mode this is much better like TH0=22°C / TH1=23°C / TH3=6°C and TH4=13°C, and the room is cooling down.
I've already check the following:
Refrigerant charge is right based upon a complete recovery.
The unit is not at the end of the refrigerant pipe.
The version of the outdoor sofware is v785, i upgraded it 3 years ago (for another reason) on both master and slave unit.
The outdoors units were checked by service checker and there's not stepping down control neither retry loops.
I've check hot gas valve outside there's no hot gas bypass (this problem is well known on this series).
I've fully open the indoor EEV and the superheat is still high (23°C) while the 16 other indoors are on heating mode, for example.
I've changed the computer unit in heating mode 30mn and check the 3 way valve action in the BS box and that was right.
I've also try to shut some EEV (on 5 units in heating mode) in the nearest area...hoping i will recovery some refrigerant but in vain.
At last i've tried to put some units in cooling mode (also in the nearest area) and the problem occurs like the computer room (high superheat)
The only way to get a good efficiency is to set the whole system in cooling mode, like in summer, but it's not possible right now.
I do not understand why the system ran well during a couple of years and maybe a dear RE member could help to go ahead.
Kind regards
cool#9