Daikin vrv3 oil return noise

[Suffolk Fridge]

Has anybody experienced loud vibration noises eminating from pipework during the condensing unit's oil return process or from the bs boxes equalising? I have several large sites full of daikin vrv3 and all are making very loud noises. Have had service checker on, it also appears to happen when either of the 4 way valves de-energise on the condensing unit.
Any suggestions or similar experiences?

[cool#9]

Has anybody experienced loud vibration noises eminating from pipework during the condensing unit's oil return process or from the bs boxes equalising? I have several large sites full of daikin vrv3 and all are making very loud noises. Have had service checker on, it also appears to happen when either of the 4 way valves de-energise on the condensing unit.
Any suggestions or similar experiences?

I Suffolk Fridge.
We have had this problem on VRV III HR, P series.
Try the following code
_mode 2 / binary set 41, change binary code from 3 to 0.( to avoid noise in heating mode in the bs boxes ).
Hope this help
rgds
cool#9

[mekaniko5]

I haven’t experienced this however please share with us the main reason behind the vibration, whether its because of resonant frequency or something else.

[Obi Wan]

In order to prevent any miscommunications in relation to the noise issues on VRV III systems I can give you the following explanation.

As you may be aware the on all previous VRV heat recovery systems (including VRV II) the entire systems had to pressure equalise when the one BS Box changed mode and also that indoor units in heating mode with thermostat off had the EEV partially open (12%).
These two functions were changed on VRV III. Now the system does not need to pressure equalise if only one BS Box changes mode. Also the EEV on indoor units in heating thermostat off can now fully close as the bypass can be carried out within the BS Box.
The noise can occur when one on the heat exchangers on the outdoor unit changes mode. i.e. from condenser to evaporator or vice versa. At this time indoor units in heating mode thermostat off will have high pressure in the gas line which may backflow across an EEV within the BS Box. This is the sourse of the noise, but will not happen every time or on all sites.
You can set the outdoor unit to return to the old method where the EEV remains 12% open in heating thermostat off. To do this program setting 41 in mode 2, binary 3 to 0
This will mean there is no backflow across the EEV in the BS Box.
The main problem was resolved by updating the software on the outdoor unit main PCB on mass production units and was done quite some time ago. On site where the problem is present you can reprogram the PCBs or simply replace the PCB with a new spare part PCB. (right side on the single module, and on all main PCBs on the multi modules)

The latest version of the software in 0.0.3

Regards
Obi Wan