Problem with a Sanyo multisplit

[marc5180]

Got called to a fault today on a sanyo multi-split unit. Not sure of the model number i can remember that its a SAP .
The condensor has 4 connections for indoor units, 3 of them are used, each of them feed a small office, so 3 indoor cassettes. the problem is that the office on the left works the one in the middle works but the one on the left doesn't work, on heating or cooling.

I turned all of the indoors off apart from the one that wouldn't cool/heat to check if the compressor came on thus ruling out the sensors on the indoor...it did so i went to the indoor but still the indoor wasn't cooling at all, the fan was running but air off was 19deg.

Next i started from the beginning and belled the interconnecting wires out and found A going to C pipeworks indoor & C going to A's pipeworks indoor. So i swapped them around to what they should have been.

Back at the condensor each leg to the indoor units (suction + liquid) i noticed that there was a LEV for each of them. I decided to swap the heads around from the unit that wouldn't cool to the 4th leg that wasn't being used. I swapped them around thinking that this could be the cause but still that didn't seem to work. By the feel of the pipes it did feel like the expansion valve (LEV)wasn't opening and letting refrigerant down the pipework so i decided to pump the unit down and swap the pipework down to the leg that wasn't being used, vacced out and let the gas back in the system. Started the unit up and the sames happening now. the other 2 are cooling, heating fine but the 3rd one wont do either?
I've spoke a guy at sanyo who couldnt do enough to help although he too was miffed. It can't be short of gas because the other two work and when i turn them off and just have the faulty one on it still doesn't work.
Any ideas guys?
Any ideas guys?

[superswill]

maybe a long shot,crossed pipes? i mean if the cable is who knows

[marc5180]

Yes, i thought that but if that was the case then surely 2 of the indoor units wouldnt work properly and not just the one?

[superswill]

does the system have a self pipe check mode?
have you run the indoors up one by one?
could there be a blockage in the faulty unit?

just throwing ideas up

[marc5180]

does the system have a self pipe check mode?
Not that i'm aware of no.


have you run the indoors up one by one?
Yes i have run the indoors up one by one, both circuit 1 and 2 works fine but when i put 3 or C on cool/heat the compressor runs but nothing gets to the evaporator.

could there be a blockage in the faulty unit?
I think tomorrow i'm going to reclaim and blow through with nitrogen to check for any blockages. It looks like the problem is with the LEV not openeing but i dont know how to check it. Iv changed the heads around. I thought i could use my solonoid magnet to put it on top of the valve but i've been told that this will not work.

[superswill]

if it was the LEV at the outdoor was at fault wouldnt swapping the ports of solved this?

again a long shot but before using OFN try swapping the indoor PCB with one that works maybe its not sending the right signal to open the LEV if the indoor coil is not getting hot or cold it sounds like a flow problem,

do you have to address the indoor unit to the corresponding outdoor port? A=0 B=1 or how ever this kit works? is this right?

[marc5180]

Got back to the unit today first thing and reclaimed the refrigerant. Then i decided to blow OFN down the pipes to check that none of them were crossed or blocked, when i started to blow down the suction on C pipework nothing was coming back on the liquid. Decided there had to be a blockage ans as it was 1/4 copper i was hoping it would be easy to find. I worked back from the unit on the liquid line and found the first braize about 15m away. I cut it open and lo and behold it was blocked solid so who ever had fitted the units hadn't even bothered to commision them to see if they were working.... The strange thing is though the people in the office seem to think that it used to work but how? Its only 2 years old.
Also with it having a blockage i would have expected to see the suction fall to a near vacuum because in effect the system would be pumping itself down.


could there be a blockage in the faulty unit?
So you were right...thanks

[Slim R410a]

Got back to the unit today first thing and reclaimed the refrigerant. Then i decided to blow OFN down the pipes to check that none of them were crossed or blocked, when i started to blow down the suction on C pipework nothing was coming back on the liquid. Decided there had to be a blockage ans as it was 1/4 copper i was hoping it would be easy to find. I worked back from the unit on the liquid line and found the first braize about 15m away. I cut it open and lo and behold it was blocked solid so who ever had fitted the units hadn't even bothered to commision them to see if they were working.... The strange thing is though the people in the office seem to think that it used to work but how? Its only 2 years old.
Also with it having a blockage i would have expected to see the suction fall to a near vacuum because in effect the system would be pumping itself down.

So you were right...thanks


Hi Marc,

What was the 1/4" pipe blocked with?

Cheers

[marc5180]

Hi Marc,

What was the 1/4" pipe blocked with?

Cheers
It was blocked with cupro/braizing rod when the pipe had been installed.
The weird thing is...i've just been told by another engineer that went to it that the unit was cooling because as he was looking at it the guy in the office asked if he could turn it off cos it was getting too cold:confused:

[superswill]

It was blocked with cupro/braizing rod when the pipe had been installed.
The weird thing is...i've just been told by another engineer that went to it that the unit was cooling because as he was looking at it the guy in the office asked if he could turn it off cos it was getting too cold:confused:


was it cooling or just air movement,id ask as all the customer feels is a "bloody draft"

[marc5180]

The other guys is adamant it was cooling but it can't have been can it.

[superswill]

The other guys is adamant it was cooling but it can't have been can it.

well no is the honest answer,it could never of worked but lets just just put this down to the air con fairies

[sigorst]

Once again, its not the kits fault!

[superswill]

Once again, its not the kits fault!

another week from hell then mate? damm them customers