Fault on a Hitatchi again.

[marc5180]

Hi all, i got called to a fault today on a hitatchi multi RAS-5FS with 7 indoor units. On the controller the it was flashing "43" and also on the main PCB in the condensor it was flashing this.
I'm thinking that it's short of refrigerant because the compressor sounded very noisy and the condensor fans weren't running, i put my gaugues on and had 5 bar suction and 10 bar discharge. I also noticed oil around the HP switch.
I tried phoning Hitatchi Technical for the fault code but they didn't know.
Hitatchi are the one manufacturer that i have no fault codes on, if anyone has any to send to me i'd appreciate it.

[nike123]

Hi all, i got called to a fault today on a hitatchi multi RAS-5FS with 7 indoor units. On the controller the it was flashing "43" and also on the main PCB in the condensor it was flashing this.
I'm thinking that it's short of refrigerant because the compressor sounded very noisy and the condensor fans weren't running, i put my gaugues on and had 5 bar suction and 10 bar discharge. I also noticed oil around the HP switch.
I tried phoning Hitatchi Technical for the fault code but they didn't know.
Hitatchi are the one manufacturer that i have no fault codes on, if anyone has any to send to me i'd appreciate it.


Try to find error here:
www.hitachiaircon.com/files/attachments/PDF/TCGB0017_02-02.pdf

That was second result on Google for RAS-5FS:rolleyes:

[marc5180]

Compressor/inverter failure? I've had it running though for 10 mins.

[nike123]

Compressor/inverter failure? I've had it running though for 10 mins.
Reset and try again, check wiring, check PCB connectors, check correct phase sequence.

[joe-ice]

code 43 occurs when the pressure ratio falls below a set point more than 3 times + the noise would leave me to think you have a compressor running but not pumping:rolleyes:

[marc5180]

what do you mean by pressure ratio? What i did notice was that when i first reset it and started it back up the compressor was really loud then quitened down. Then the compressor stopped along with the condensor fans then it started after a minute or so then went off again and tripped like you say after 3 times. Could this not be down to lack of refrigerant?

[stuartwking]

Hi marc tried to upload a page of fault codes but wouldnt work.The Hitachi site is good for manuals.Have a check of the hot gas bypass valve is working correctly and could well be short of refrigerant,,

[joe-ice]

when the difference between the head pressure and the suction pressure decreases when its not meant to its senses this & shuts down;)

[marc5180]

So it could be lack of refrigerant? I think i'm going to pump it down first of all to check if the compressor is ok.

[nike123]

So it could be lack of refrigerant? I think i'm going to pump it down first of all to check if the compressor is ok.

Is this new, virgin instalation or, system who is already been in use?

[marc5180]

This is quite an old system that has been running for the past 10 years.

[Thermatech]

Looked at 6 month old Set Free 3 pipe (latest 410a model)system the other week which had alarm 43 pressure ( low compression ratio ). The system cannot get up to target discharge pressure in heating & can see small diff between suction & discharge pressure so it stops & reports alarm 43.

Your gauge readings seem to confirm this. But to be sure its always a good idea to check that the pressure sensors & circuit board are reading the same pressure as your gauges. Scroll through on SW2 to look at hp & lp data. Check standing pressure data & then running data.

Had one last year that was running at 41 bar because discharge pressure sensor was reading 29 bar , hot gas at the indoor units at about 70 deg C !! oops.

Good idea to check for any incorrect bypass or faulty rv before reclaim full charge. Try running in test heat & test cool. Use two sets of gauges one set on the service valves & one set on the hp & lp service ports to help you see whats happening in the outdoor unit.

Otherwise might be soft compressor not pumping very well.

BTW
Turned out to be reversing valve jammed in cooling possition on the new system.

[Gary]

Did you check the compressor inlet superheat?

It sounds like the compressor valves are broken, but another possibility would be the reversing valve leaking through, allowing high side pressure to dump directy into the suction. Check the temperatures across the reversing valve to see if hot gas is entering the suction.

[paul_h]

Why all the interest in getting fault codes for an obviously faulty system?
Fault codes are handy if you come to visit a dead system with a flashing code, or a troublesome system that never fails when you are there but has a history of flaking out, or one cutting out on a fault that you don't understand. But they aren't always needed to diagnose any system.
You obviously have a system there giving bad pressures and is running right in front of your eyes. From the sounds of it you are not looking at a faulty controller, PCB or thermistor so why the big need for fault codes? You need to know the regular operating pressures, temps, current draw, sure. But thats all you need, not fault codes (they're only handy when the system isn't starting at all, or cuts out for no obvious reason).
You were there when it was running, what was the discharge temp, suction temp, reversing valve in and out temps for suction and discharge etc?

[Gary]

Someday, someone will get the fault codes right and then we won't have to think.

In the meantime, the codes show us symptoms rather than faults and may at best point us in the right direction.

[paul_h]

I'm not trying to insult marc5180's intelligence, he didn't need a fault code when he found that system with the loose txv bulb, why is he always asking for them every time the option is there?
Sure they are nice to have for all the reasons I stated above, but surely buy the time you've come home and decided to post here, you must of spent some time thinking the problem over, and decided probable cause and taken other measurements other than pressure and writing down the fault code/number of flashing LEDs!

edit: BTW gary I'm hoping you were contradicting your point on purpose

[Gary]

edit: BTW gary I'm hoping you were contradicting your point on purpose

Hmmm... where did I contradict my point?

[paul_h]

Someday, someone will get the fault codes right and then we won't have to think.
So mr "pressures are meaningless - you need all the temperatures" is now saying all you need is a fault code and now we don't have to think?


In the meantime, the codes show us symptoms rather than faults and may at best point us in the right direction. Most of the faults I've found don't even get the correct fault code. I know that condition is adressed in your first statement, but surely you have to take the measurements yourself to verify whether fault condition is met or if the controller is reading a false value due to controller fault.
But in my reading of your statment, all you'll need in the future with a perfect fault code system is the pressures and the fault code.
It seems to go against your diagnostic system in general, ie pressures are all we were given, and the hunt for a fault code instead of diagnosing the system with your own test equipment and observations. ;)
Again, no disrepect to marc, but units of all types were failing before the internet and fault codes came about. Normally measurements and observations were taken, and I know he had an idea of what he suspects before coming here, so I'm not accusing hiim of anything. Its just that he came here without any temperatures which would give him more of a clue of the problem

[Gary]

But in my reading of your statment, all you'll need in the future with a perfect fault code system is the pressures and the fault code.


Nope... you won't need the pressures, either. In fact, the system will call you and tell you what is wrong and what part to bring.

[paul_h]

OK, you can quit laughing at my expense now.
Rep points added to your account because I don't have anything else to do.

edit: I swear there was more smilies to the previous reply to gary, as I wasn't taking it so seriously. It looks so serious with just the one.
My typing is atrocious on this old IBM M spring buckle keyboard!
edit2: or is a a buckling spring keyboard? I dont; know, it's an old scottish 42H model that weighs 2kg and it's useless because the num pad doesn't work and you have to press the keys so hard.

[marc5180]

Why all the interest in getting fault codes for an obviously faulty system?
I wanted to know the fault code so that instead of possibly wasting time trying to find the fault on things such as Hot gas bypass, 4 way valve, transisters, contactors inverter board, compressor etc, the fault code easily pinpoints the problem and saves me a lot of time.
I only asked for a list of fault codes because i don't have any as a reference for in the van.
BTW if fault codes are so useless then why do manufacturers use them?

[Gary]

Predicting the future isn't all that difficult. It's more evolution than revolution. Self-diagnostic systems have been around for a long time and they are getting better.

Will they suddenly achieve perfection? No, but they will gradually become more accurate more often than the average service tech... and then there will be less demand for average service techs.

The handwriting is on the wall.

[paul_h]

I wanted to know the fault code so that instead of possibly wasting time trying to find the fault on things such as Hot gas bypass, 4 way valve, transisters, contactors inverter board, compressor etc, the fault code easily pinpoints the problem and saves me a lot of time.
I only asked for a list of fault codes because i don't have any as a reference for in the van.
BTW if fault codes are so useless then why do manufacturers use them?They dont tell you that stuff anyway. They tell you thermistor out of range, fan locked up, compressor over amps, hp etc.
The don't tell you r/v faults, system blockages, contactor faults etc All the stuff you can see for yourself if you are there.
Also, half the times the fault codes don't come up, the other half of the time you need to be measuring the values yourslef to know if it's a genuine fault or a faulty sensor.
Yes they are handy to have, but not needed before you even diagnose a system.
Manufacturers use them so the novice without a clue can tell them the nature of the fault. Not the guy there with pressure gauges, clamp meter, mulitimeter, touch probes, experience etc.
They're not worthless, I use them to ascertain iwhether the indoor or outdoor unit is at fault, but that's it. You know the fault was at the outdoor though.

[marc5180]

Got back to the site today and ran it up again in heating. It sounded very noisy but then it quietened down and sounded like it was going to stall then cut out within 5 minutes. The discharge pressure didn't go over 12bar even with the condensor coil blocked off whilst the suction pressure was at5 bar.
I turned the controller onto cooling and had an air off the indoors of around 10k (18F). This stayed on for longer than when it was in heating mode say 5 minutes but when i went to the condensor "43" was flashing up again.
I checked that the pressure sensors & circuit board were reading the same pressure as my gauges by setting the dipswitches. At this time i noticed that DSW4 No1 was set to on, which im told is "emergency operation" which leads me to think that the compressor is at fault due to it being in this mode for i think around 2 years since another company changed the inverted board and obviously didn't switch the dipswitch back to off
I did check the compressor inlet superheat and i got 5K, i also checked the amps that it was pulling which were around 13amps per phase which did seem high the top of the compressor temperature got up to 85C.
I spoke to hitatchi and they think its the compressor valves so have suggested a new compressor and inverter pack.

[stuartwking]

Sounds good to me marc,. The dsw1 is just for emergency operation, If im right i believe its dsw 7 to disable compressors. I cant believe the system has been running for 2 years with dsw1 on!, lol,.Also i think Hitachi design there comps to run up to 120 deg c.,The boys who handle up north for there technical line are legends, Paul and Danny.Dont you just love Hitachi!..

[marc5180]

yeah i spoke to paul today, he was very helpful. Just got off the phone from parts and i have found out with an inverter pack i wont just get the board i will get another 9:eek: things as well such as transistor, contactor, capacitor and transformer cant remeber the other 5 things but i'm not looking forward to giving the customer the price:rolleyes::rolleyes:

[marc5180]

Also does anyone know how to get the temperature readings by using PSW1 , 2 and 3 on the main board. I had it earlier but i forgot and would like to make a note for future reference:D

[Thermatech]

Outdoor control circuit board.
SW2 hold down for about 5 seconds.
Scroll through system data with SW2 forward scroll & SW3 reverse scroll.
You need service manual to see what each item is.

easy peasy japanesy.

[stuartwking]

Marc look for rd1 while scrolling through your setting mode 2,,.rd1 = mc1,,. rd2=mc2.Hope that makes sense..

[Thermatech]

Mark

I really hope the compressor is the right daignosis ,,, but have bad feeling about this.
If you missed something !!!!!!!!

Been there ,,,, done that ,,,,, not good.

Do you have ballance power supply to compressor from inverter ?
1/ earth to L1 at compressor = ?
2/ earth to L2 at compressor = ?
3/ earth to L3 at compressor = ?

If the voltage at each phase at the compressor is the same giving a ballanced 3 ph power supply to the compressor from the inverter then 99% sure inverter circuit all ok ,,,, so no need to replace all the components.

[marc5180]

Marc look for rd1 while scrolling through your setting mode 2,,.rd1 = mc1,,. rd2=mc2.Hope that makes sense..
Nope it doesn't make sense:rolleyes:

[marc5180]

Mark

I really hope the compressor is the right daignosis ,,, but have bad feeling about this.
If you missed something !!!!!!!!

Been there ,,,, done that ,,,,, not good.

Do you have ballance power supply to compressor from inverter ?
1/ earth to L1 at compressor = ?
2/ earth to L2 at compressor = ?
3/ earth to L3 at compressor = ?

If the voltage at each phase at the compressor is the same giving a ballanced 3 ph power supply to the compressor from the inverter then 99% sure inverter circuit all ok ,,,, so no need to replace all the components.
You have a feeling that it's not the compressor... why?
I disconnected the terminals from the compressor when i was there and ran it up and tried to measure the voltage going to each of the leads but the unit kept tripping out on a fault "58". I'm working across the road from this unit tomorrow so i'm going to call in and check a few things such as measuring the voltage to each of the terminals at the compressor...(can i do this with the leads attatched?). I know that they should be withing 3-4% of each other.

[Thermatech]

Just measure for ballanced supply from inverter to compressor while it is running & connected to the inverter.
Some engineers like to measure between the phases & also you can use clamp meter to measure amps on each phase / comp winding.
Anyway ballanced is what you are looking for.
Alarm 58 is something to do with fan motor over current on latest models. I know the unit you are looking at is much older but the fault codes tend to stay the same.

Your idea of pump down test was good.
Also run system in test heat mode, then shut discharge service valve on outdoor unit.
If no other fault with system the comp should run staight up to max discharge pressure & cut out on HP switch ,, result = comp good.
If comp gradualy gets up to high discharge pressure or cannot get up to cut out pressure = comp needs replacement or internal bypass in outdoor unit.
Do this test with two sets of gauges connected to be sure whats happening at the outdoor unit.

If you replace compressor & inverter components & system still does the same = bad news & customer not paying bills because he is paying you to make correct diagnosis not to guess at his expence.

Please be sure before commit to compressor & inverter replacement.

[marc5180]

Thanks Thermatech, like i said i'm going to call tomorrow so i will let you know my findings.

[marc5180]

Went back to site today and firstly checked that the 4 way valve was operating correctly and was not seized and also that hot gas wasn't passing through to the suction- which it wasn't.
Then i checked each of the terminals going onto the compressor and they were all within 2 volts of each other.

I put the clamp meter on the compressor terminals and they each ran at about 11amps but after say 30sceonds or so the amps went up to 19 where the compressor sounded like it was going to cut out stall, then the amps went back down to around 15 and it cut out.

I then put the controller on heating and closed the discharge port and the discharge rose all be it slowly from 10 bar to 15 bar where it sat for about 15 seconds before the unit switched off again.
I do think it is the comprerssor as this should have shot up to around 28 bar before cutting out on HP but it didn't.
Do you guys agree?

[nike123]

It looks like it is compressor. He has some mechanical damage and from time to time consume high amperage. That triggers cutting on high amp. protection of inverter circuit.

[Gary]

Went back to site today and firstly checked that the 4 way valve was operating correctly and was not seized and also that hot gas wasn't passing through to the suction- which it wasn't.


What was the compressor inlet superheat?

[Thermatech]

Good work Mark

I think you can be sure now that the compressor is what I call 'soft' in other words no pumping.

But no need tio replace all inverter components because inverter working correctly.

[marc5180]

What was the compressor inlet superheat? The compressor inlet superheat was 5k

[marc5180]

Good work Mark

I think you can be sure now that the compressor is what I call 'soft' in other words no pumping.

But no need tio replace all inverter components because inverter working correctly.
I wasn't going to replace the inverter yesterday until i spoke to hitatchi who advised to get the pack as well as the compressor, he must have been on commission though as the inverter pack is over £1000:eek:

[Gary]

I wasn't going to replace the inverter yesterday until i spoke to hitatchi who advised to get the pack as well as the compressor, he must have been on commission though as the inverter pack is over £1000:eek:


The compressor inlet was 5k

I agree with Thermatech... it's the compressor.

[marc5180]

The compressor was ordered today so it should be here for monday, i'll let you know of the outcome.

[marc5180]

Just to let you know fitted the compressor as well as the inverter pack the other day and recommisioned the system. All is running fine now, the compressor at full speed was pulling 7amps 50% less now.
Thanks for all your help guys

[marc5180]

Got a call back to the unit today... not cooling.
Found it going off on high discharge temperature at 25 bar, checked the condensor fan but it wouldn't come on at all. Checked to see if it was seized which it wasn't and also checked the resistance of the coil sensors that tell the fan to come on. It's looking likely that the board is the problem, not looking forward to telling the customer:rolleyes:

[Inverter man]

Guys, sorry I'm late in on this thread, I'm relatively new to this forum and presently do not know how, ( when convenient for me) I can easily submit or give access to my electronic data. I have a lot of info and experience with Hitachi kit and would be pleased to offer assistance when and where I can. Any suggestions and help would be appreciated.

[gille]

I have RAS - 5FSVG technical catalog with error codes. PM me your mail, i will send you, if that is what you looking for.

[Brian_UK]

Guys, sorry I'm late in on this thread, I'm relatively new to this forum and presently do not know how, ( when convenient for me) I can easily submit or give access to my electronic data. I have a lot of info and experience with Hitachi kit and would be pleased to offer assistance when and where I can. Any suggestions and help would be appreciated.It's very easy and simple here I.M.

Just mention that you have a document and people will fall over themselves to get a copy from you. ;)

Any public advice that you are able to give in response to any questions is also much appreciated. :D

We try not to publish in posts to avoid spammers picking them up.

Most people will use the Private Messaging (PM) system to pass information.

[wolf]

i had same problem check indoor unit capilari frezeng up!replace dryer it will be ok