Toshiba Multicontroller Box

[skilts]

Hi i have a 3-pipe Toshiba VRF on R407c where the multicontroller box is noisey & faulty, Toshiba say they are no longer available, i could understand this if it was on R22, Anybody got any ideas or stripping out a system ?.

[superswill]

had the same prob a while ago, had to remove box and indoors and fit new splits the the area,

try all distributors of Toshiba to see if there is an odd one on someones shelf

[BuNcHy]

Got that problem at the moment with 2 down on seperate floors. Tosh obviously stopped making them for a reason!

[skilts]

The site i,m working on has 10 of these systems, perhaps we should scrap 1 system & use it as spares,
I also understand that a number of compressor failures have occured on this site, perhaps Tosh stopped making it as it seem's to be very troublesome

[Loops]

Skiltz,

You are right Toshiba stopped making the 3-pipe R407C multi controllers about 5 or 6 years ago.

Why? Well R410A is the reason, it's called progress.

I know these systems inside out as I worked for Toshiba for 27 yrs.

By noisy do you mean really noisy ie easily heard at ground level or maybe sounds like a jet taking off?

If so the most likely scenario is that a heating solenoid valve (SVD) is open in cool mode (or visa-versa).

Two options here
1) solenoid valve is mechanically suck open
2) the pcb is energising a valve when it shouldn't be.

So the test is to run all the indoor units in cool mode and if you get the noise disconnect the SVD plug from the board (red one on bottom edge of the board).

Then reconnect the plug and try heat mode if it's noisy then disconnect the cooling solenoid valves (SVS) this is the white plug on bottom edge of pcb.

If the nose stops when you disconnect the SVD or SVS plug then the pcb is faulty.

If not it's a seize solenoid valve and you'll have to take off the sump to determin which valve is faulty (by touch)

If the noise isn't too bad, maybe a bit or gurgling like a small stream then the system could be short of charge.

Let us know how you get on with diagnosis.

Cheers

Loops