Big suction pressure on sanyo vrf

[shujin]

I have a strange situation with a new unit at startup:

- the suction pressure 22 bar
- the discharge pressure around 30 bar
- outside temp 30 degrees Celsius

The unit is a 3 pipe system but when the system works the temperature on the condenser is not rising so the fan doesnt extract ay heat from the condenser

If i close liquid line and the outlet gas for heating the suction gas line remain at 22 bars and doesnt drop the pressure.

Any ideea of what could be?

Thanks in advance

[DL A/C]

how new is the system?? has it worked ok after commisioning?

[Thermatech]

I am not expert on Sanyo VRF systems but suspect they are somthing like Daikin & Hitachi systems.

If you are running in cooling mode but not getting hot discharge gas in the outdoor coil you need to inspect the compressor discharge pipe from the compressor through to the outdoor coil & see what is happening to the hot gas.
If you are getting 22 bar hot gas in the suction line even with liquid & discharge service valves shut then there would seem to be a discharge to suction bypass in the outdoor unit.

The prime suspect in this case will be the 4 way reversing valves.

If you have another system on site you can see how the hot gas passes through the 4w rv with correct operation.
Also carefully look at the service manual refrigerant flow diagrams .

[acnerd]

I have a strange situation with a new unit at startup:

- the suction pressure 22 bar
- the discharge pressure around 30 bar
- outside temp 30 degrees Celsius

The unit is a 3 pipe system but when the system works the temperature on the condenser is not rising so the fan doesnt extract ay heat from the condenser

If i close liquid line and the outlet gas for heating the suction gas line remain at 22 bars and doesnt drop the pressure.

Any ideea of what could be?

Thanks in advance

I worked on a Sanyo VRF R410a system a few months back in the winter. The system had almost no performance and when Sanyo engineers hooked their laptop to it, found the discharge pressures at 33 Bar within a few seconds of startup. The system didn't report a fault, but it was clear it was contaminated with Nitrogen. I had 31KG R410a to recover, and it took 12 x 10kg reclaim bottles.

Evacuated and recharged with all valves forced open. Been running fine ever since!!

[shujin]

Thanks for sugestions. I will try to recover all the refrigerant and do the charging one more time. I have a similar model near this one that works perfect so i will be able to verify the normal function on the 4 way valve but it's hard to believe that a new unit tested on the factory can have already a 4 way valve broken.
How can i force on ECO-i Sanyo the valves to be open when i do the charging?
Also i know that RAC valves are partially open or you suggest to open manually these ones also, and if so how this can be done?

Thank you one more time for ideeas!

[acnerd]

The units vary between countries, so I don't know if they are the same, but this is what I do in the UK:

Power off the outdoor unit
On the outdoor PCB in the general area of the top right-hand-side is a small jumper plug which is over the "Short Circuit" pins. Remove and place on the "AP" pins.
Remove the blue/pink control wiring plug (peace of mind)
Power on the unit
All the valves will energise within in a few seconds; you'll hear the clicks.

You can then pressure test, evacuate etc.

The reversal of the procedure is needed to get back to normal operation.

[shujin]

The system is new just arrived from Japan.I have recovered the so called refrigerant, vacuum it and charged with new R410a. Now is working perfect.Thank you for tips&tricks :-) All the best!!!

[techguy]

Some Daikin guy must have sneaked onto the site and contaminated the system :-)


Only Jokin.