Daikin vrv II system standard compressor not running

[laffanray]

I have full load conditions on system, invertor compressor running fully but at no stage is standard compressor contactor being called for from pcb, gas pressures good. no faults being displayed on any indoor controller or centralized controller, has anyone experienced this issue?? (REQY10M)

[troymedhurst]

I have full load conditions on system, invertor compressor running fully but at no stage is standard compressor contactor being called for from pcb, gas pressures good. no faults being displayed on any indoor controller or centralized controller, has anyone experienced this issue?? (REQY10M)
Hi

Could someone have prohibited std compressor, if they had a problem with it?

You could check using mode 2 setting 19
• To inhibit STD1 and STD2 compressors fromoperating → Set setting mode 2 from No. 19 to No.2. (REYQ8M to REYQ16M)
Press and hold the MODE button (BS1) for 5 sec. or


the SET button (BS2) 19 times.the RETURN button (BS3) once.the SET button (BS2) once.
the RETURN button (BS3) twice.the MODE button (BS1) once.




Did you check supply to contactor?

Good luck

Troy

[install monkey]

also vrv2 will rotate sequence to maintain even run hours and disable a compressor if it detects fault

[laffanray]

Tks Troy, compresser is not prohibited, checked that as i know the unit had previously been worked on. when i put system into test mode std comp will run and no faults appear at conclusion of test, metered contactor supply no sign of voltage.
monkey rotation of comps might be occurring but surely it wont leave the system with only the invertor running when theres a high demand from the indoor units,... i suppose nothing would surprise me at this stage!!! :)
cheers lads

[troymedhurst]

Just a thought, could the system have been set with the demand mode?

Possibly set to run at 60 percent power consumption. I have never used this function, but if the system was set at a lower power consumption, then I guess this could stop the std comp running?

Good luck
Troy

[laffanray]

Finally got back to site last friday armed with a service checker and a colleague with experience using it, found pressures normal but standard compressor was not being called for at any stage, watched run and with inadequate heat reaching indoor coils so correct conclusion of system overcharge was arrived at, after weighing out 20kg of 410 all indoor units preformed perfectly with only invertor comp running. maybe outdoor was oversized first day??? also would have to think different REFFRIGERATION service engineers added gas at different times probably based on gauge readings....lack of training!!!! anyway lesson learned if in doubt insist on service checker!!!! Thanks anyway lads.