Sanyo 3-pipe not heating

[CraigMac0113]

I'm Having a problem with a Sanyo R410A VRF system.

I hope somebody can throw some ideas my way before i start pulling out the gas.

22 fan coils when in heating, all display the standby heat symbol and a little heat reaches the coil but not enough for the unit to start heating.

Meanwhile, the condensing units start up, the inverter comp, and the fixed comp's start running, the discharge pressure runs around 25-29 bar, suction around 5-6 bar, the discharge pipe was getting too hot to hold,
but within 10 minutes, everything winds down untill it stops altogether.
5 minutes later the cycle starts over.

When i run only half the system, the standby symbol comes off, the units run with poor heating but condenser still cuts out after 10 mins.

Pipework not crossed, checked correct valve opens in all SV boxes, tried a power reset, even tried adding a couple of kilos of gas but makes no difference.

[marc5180]

When the heating standby comes on the controller i thought that meant the units are going into defrost mode?

Have you checked they aren't going into defrost?

[CraigMac0113]

When the heating standby comes on the controller i thought that meant the units are going into defrost mode?

Have you checked they aren't going into defrost?

Hi Marc
Thanks for responding
It does also mean defrost, from what i understand it will appear when ther is insuficient heat in the coil, so it could be pre-heat or defrost.
The condensers aren't going into defrost, they are running in heating mode but not for long enough.

[marc5180]

Something seems to be causing the system to shut down,
possiby discharge temp sensor reading higher than 120ºC.

Do any fault codes show up? Any lights flashing on the Outdoor PCB to indicate a fault?.

Have you looked through the data/sensors on the outdoor PCB or even by using the remote controller?

Whats the model number?

[CraigMac0113]

Hi Marc
The model number is SPW-C1405DZH8, there are two of them twinned up on this system.
There has been no fault code, no abnormal lights flashing on the PCB.
I would of expected a fault appear if i had a discharge temp problem, eg. P03/P17.

Not retrieved data from remote control yet as i have been using Toshiba RBC control manual to find codes.
That may sound stupid but they are the same when setting up the fan coils.
They start to differ when it comes to condenser running data.
Do you know what codes are for comps 1,2,3 temp/pressure information?

[croc1774]

hi, can you get it going in test?

[techguy]

Hi Craig,

29 bar is the pressure at which the system unloads. If it is achieving 29 Bar
and as you say the discharge gas pipe is to hot to hold.

Then the problem is not with the outdoor units it's at the indoor units.
1. Either your over charged
2. The SVK boxes are not opening
3. There's a blockage in the pipework
4. Your interconnecting cables are crossed and your not looking at the correct indoor units. IE. the cable may be going to X indoor units but the pipes are going to Y indoor units .

Have you checked these options.

Do you have a manual for this machine. It is possible to connect a remote controller to terminals 3+4 at the outdoor unit and investigate the temperature sensors at each individual indoor unit.