Toshiba RAS 13 SKV problem....

[igi]

Hello!

This is my first post here. I come from little contry Slovenija and i apology for bad english. Last four years i have my own bussines for fitting up small split air condition. Here in slovenija we dont have any school or course for servicing air condition, so i read a lot of internet forums and books.

But i have problem which i cant rescue so I need advice...

Symptoms are:

Air condition toshiba is 2 weeks old, costumers use it for heating. First clima stops and error code was: 03 1d (compresor doesnt rotate). I changed inverter elecronic for outside unit. Clima starts and work 5 hours. Now i have funny problem.

When i use it for heating unit starts normaly and increasig power of compresor slowly. I measure electric power which increasing for about 600W, same is with pressure. Its increasing to 30 degree Celsius. But.... now everything start to droping down and stop at 200W electric power and pressure at 20 degree Celsius. Compresor work all the time. "Accumulator" in front of compressor starts to freezing?!?!?!?

When i changed mode to cooling is everything more confusing. Pressure goes to vacuum!

I fill the unit with new refrigerant gas, check sensors, changed indoor electronic, checked pipes (2 meters long).

What is the most possibility problem? Compresor, 4 way valve, Pulse modulating valve, ...?

Thank you very much for help

Igor

[Thermatech]

Regrigerant blockage
No refrigerant flow through indoor unit back to outdoor unit in heating or cooling.

In heat mode the outdoor unit pumps hot gas into indoor unit so indoor coil gets hot
but
because of blockage warm liquid does not flow back to outdoor unit.

Run the system in cooling for awhile to get the refrigerant back to the outdoor unit.
then
run in heat mode & follow the hot gas through the pipe to indoor unit.

You should be able to find the blockage if you follow the temperature of the refrigerant as it goes arround the system.

If the outdoor coil does not get cold in heat mode then refrigerant is not getting back to the outdoor coil.

[igi]

hello!

One more funny symptom. Toshiba somethimes work perfect, with no problem, so i suspect compresor or valve

[SteinarN]

When i use it for heating unit starts normaly and increasig power of compresor slowly. I measure electric power which increasing for about 600W, same is with pressure. Its increasing to 30 degree Celsius. But.... now everything start to droping down and stop at 200W electric power and pressure at 20 degree Celsius. Compresor work all the time. "Accumulator" in front of compressor starts to freezing?!?!?!?


What ambient temp have you when the acumulator is freezing?

I suspect the 4-way valve is faulty allowing liquid from the inndor unit enter the compressor suction in heat mode. The electronics is sensing no superheat and is closing the PMV, thus low suction and discharge pressure.

[paul_h]

It's all to do with temperatures, I suspect blockage somewhere too.
Just like a tx valve will restrict flow and reduce temps as a normal operation of a fridge or a/c, a blockage will restrict temps. You need to trace the pipe work with a surface temp probe type thermometer to find any sudden temperature changes to work out where the blockage is.
It could be the strainer, one way valve, tx valve, accumulator, a kink in the pipework.
It could be a faulty electronic TX valve not opening.
It could be the 4 way valve too, check the discharge in, discharge out, suction in and suction out. There shouldn't be more than 4*C difference between each side in and out, normally it's even less than 4*C on a system difference.

[SteinarN]

A blockage in the system shouldn't cause the accumulator to freeze up. The only reason for the accumulator to freeze is liquid entering the accumulator. If the only fault is a blockage then it shluldnt enter any liquid into the accumulator and it shouldn't freeze either.

[marc5180]

I agree with thermatech and Paul, is sounds like a blockage.
the frosted suction acumulator is due to low suction pressure / temp.

[SteinarN]

I ask again, how can a blockage cause the acumulator to freeze up?
If say the EEV is not enough open the suction pressure and discharge pressure will be low but the suction gas temperature will be high. Regardless of where the blockage is the suction gas temperature will be high.

It is highly unlikely the fault is in a simple piece of tube since the fault is intermittent. It is much more likely the fault is in a component, the only components there is in the tube system is the 4-way valve and the EEV.

If the acumulator is freezing up when the ambient is well above freezing and the outdoor fan is running it cant be the EEV. The only possible fault then is the 4-way valve allowing liquid from the inndor unit entering compressor suction.

I would check the temperatures at all four tubes at the 4-way valve. In heat mode the temperature of the tube coming from the out door heat exchanger into the 4-way valve should have the same temperature as the tube leaving the 4-way valve going into the compressor suction.

If the tube leaving the 4-way valve going into the compressor suction is considerably colder than any of the other three tubes going into the 4-way valve then the valve is faulty.

When the acumulator is freezing up, what is the temperature of the four different tubes at the 4-way valve?

[nike123]

This is refrigerant diagram:

http://farm4.static.flickr.com/3297/3185566962_a75d83727d_b_d.jpg

[nike123]

I would say liquid in accumulator but reason is not 4-way valve allowing liquid from the indoor unit entering compressor suction (then it would refrigerant flowing back), reason could be fully open EEV. Probably bad contacts on connectors of EEV, or maybe faulty T2 sensor or not at his place!
Second reason could be that 4 way valve is partially blocked so that we have pressure drop at 4way valve and therefore too low pressure at suction accumulator and therefore frost formation on accumulator.

[SteinarN]

My bad. Of course the 4-way valve can not let liquid from the indor unit into the suction to the compressor:o

Maybe it's the EEV then which is faulty. It should hovever not be to difficult to diagnose a faulty EEV.

[igi]

Hello!

I get new outside inverter electronic and changed it, but nothing changed on working. I test all sensors with digital tester all OK. I have clima on a table in my garage so i can test it. Temperatures is approximat 10 degree.

I checked the temperatures at all four tubes at the 4-way valve. In heat mode the temperature of two and two tubes are equal (two are cold and other two are warm.) A checked all tubes and temperatures nowhere change quickly. Only change of temperature i can find is on EEV valve.

But i find something very interesting. If i warm up accumulator with hot gun befor i start Toshiba, compresor starts to rising rpm and electric power to 1400W, pressure comes to almost 60 degree celsius and start to blowing heat from inside unit. Everything work like a charm.... perhaps half hour, than accumulator starts freezing. Than i suspect refrigerant flow stops because if than i force 4 way valve to changed direction of refrigerant nothing hear in pipes (if i changed direction when clima work normally rustle sounds can hear in pipes)

And one more information: First problem with this air condition was 03 1d (compresor doesnt rotate). I changed inverter electronic of outside unit, and clima starts to work. But now i recognize that this wasnt correct problem. Today i test old electronic and it work OK to. So perhaps compresor is broken (first error was compresor doesnt rotate), but somethimes (if i warm up accumulator) work ok?

Thanks a lot guys.

[nike123]

According to what you are describing , you have moisture in your system.

[SteinarN]

I still cant understand why acumulator is freezing when the refrigerant flow stops :confused:

What temperature do you have in your workshop where you are testing the Toshiba?
Are the outdor unit fan spinning at full speed when frosting starts?
Is the coil on the outdoor unit free from any excessive amounts of frost when frosting starts at the accumulator?

[igi]

I still cant understand why acumulator is freezing when the refrigerant flow stops :confused:

What temperature do you have in your workshop where you are testing the Toshiba?
Are the outdor unit fan spinning at full speed when frosting starts?
Is the coil on the outdoor unit free from any excessive amounts of frost when frosting starts at the accumulator?

Temperature in workshop when i testing was 10 degree. Outdor unit fan spinning allmost at full speed when frosting starts. Frosting starts immediately when i start toshiba! Outdoor coil doesnt have any frost!

It is almost impossible that i have moisture in the system, because piping was new, i vacuum indor system and piping when i install toshiba and second time, when i changed refrigirant i vaccum all system including compresor. But everything is possible... So how can i get moisture out off the system? I can install drying patron if this was help?

Thanks

[nike123]

When accumulator is frozen, what is temperature of pipe between 4 way valve and accumulator?

[SteinarN]

I think we are closing in......

When frosting at the accumulator starts, is any other parts also frosting?

Like Nike says, the suction tube into the accumulator?
Some parts of the 4-way valve?
Suction tube from outdoor coil to 4-way valve?
Any part of the outdoor coil like the bends at the ends?
Tube between EEV and outdoor coil?

Edit:
Is it any difference in where frosting occurs when you start the system after you have heated the accumulator compared to if you start the system without heating the accumulator first?

[nike123]

If this is going to be hard to solve problem, then you should braze some access ports to be able to measure suction and discharge pressures.