Hitachi Set Free

[Coral Plaza]

Big probems with the RAS 30 FSN Set Free (utopia split system)
We had some problems with error code 51 (inverter problems) but that we bypassed with the dipswitches. We have 32 units on one external unit, so 16 normal and 16 viritual units, problem now is that the power was out on the unit for 2 days and after that when we started it up again the viritual units indicates a error (on 14 units)
(63) Communication Alarm Indoor never detected.
and on 2 we got
(61) Communication Alarm. Indoor stoped coummunication
(06) Power failure AT IU, Reset

Does anyone know something about this?

[Thermatech]

RAS-30 FSN is Set Free 2 pipe VRF system
Not Utopia split system

The 51 & 06 alarms indicate power supply problems which may have cause damage to the inverter for the compressor & fan motor

Suggest ensure 3ph power supply is correct with correct N connection.
Make sure power supply setting on the outdoor control board DSW7 is correct for your power supply.
Check inverter circuit & ISPM.

If all ok return 3 ph power to outdoor unit & check to see how many indoor units are communicating by using the PSW2 & 7 segment display.

All indoor units have to be connected to the H link control cable & have correct address settings.
The outdoor unit needs to be told that it is connected to more than 16 indoor units with DSW4-5 setting.

[Coral Plaza]

Everything worked with the viritual units until the power was out for 2 days.... do we need to reprogram the viritual units? and so if... how do i do that? i am going to a certifiate course in december but i sadly have the problem now... and the the help i get from hitahi is now zero, Thats Brazil..... we run a hotel and have to close down 16 rooms just for this.

[Thermatech]

The address setting at the indoor units is with dip switches so should not need reset

Check to see what indoor units the outdoor unit can communicate with using the enginners mode & 7 segment display

But please make sure of 3 ph power supply first.

[Coral Plaza]

So when i enter ras unit and the 7 segments display whats should i look for? whats does it say if its only 16 and what does it say if it is more then 16 units?

[Coral Plaza]

Problem solved..... the hitachi tecnichan had put the dipswitch DSW4 number 5 to off.... now it is on again so it is working, the know nothing down here. But now i need to resolve the (51) error... we have tested the ISPM and it is as i should. The system works with the bypass on DIPswitch DSW5 on the mainbord and DSW2 on the ISPM card. What might bet problem now? Hitachi here in Brazil say the do not know.
So the first comressor is off line now and no one knows why it doent work.

[Coral Plaza]

One more thing, how long can the system run on emergency solution?
the first compressor is turned off and the other 5 is workng fulltime more or less anyway.

[Thermatech]

The acid test for inverters is ballanced supply to compressor.
Try this trouble shoot procedure.

1/ disconnect power supply cables from inverter ISPM to compressor & make safe.
2/ make the dip switch setting on ISPM sw1 - 1 on to disregard under / over amps alarm
3/ change back DSW5 setting for all compressors running.
4/ Run inverter with compressor disconnected & motitor ISPM voltage on the 3 ph supply to disconnected compressor.
Measure earth to each phase & then between each of the 3 phases.
5/ Extream caution when monitoring live 3ph :cool:

6/ Report your readings back here

[Coral Plaza]

Now we have done the tests.... we have no power what so ever. Not to earth-to-fas or between each of the 3 phases, no 220 volts or 380 volt. U,V,W.
Incoming voltage to ispm is ok R,S,T
250 volts to ground 370 between fases.

[Thermatech]

Ok

The inverter is not working

next start check all inverter circuit components
starting at 3ph power in
noise filter
fuses
capacitors
resistors
diode stack / rectifier
ISPM module

If you have experiance with inverters & a service manual you can trouble shoot & identify which components have failed
otherwise
Get an experianced engineer to look at it.

[Coral Plaza]

Thanx for that, but hitachi do not want to come until 1 month and they will just say that the ispm card is broken and then order a new one and come back later, so it will probebly take 3 monts and we have to solv this faster.
How much does a ispm module cost in england with shippmet to brazil? We have a RAS 30 FSN 60 Hz 380 volts

Please can anyone assist us down here?

One more question, why do the inverter break? It is almost a new unit, and no the do not want to help us with the warrenty either.
We have 1 more RAS 30 NFS and 1 RAS 24 NFS and 8 RAS 20 FSN.

[Thermatech]

A power supply problem can cause damage to inverter which is why you need to make sure the 3ph power supply is correct.

The installing contractor should have the knowledge & experiance to resolve any problem like this with the equipment that he has supplied & installed for you.

If you intalled the systems yourself then you are responsible to fix it or pay experianced engineer to fix for you.

Here in UK this is normal every day call out work for most airconditioning engineers.

[Coral Plaza]

The power is ok, checked that. The do not have any service in brazil like you have in England.... We have the only Set Free system in Natal so no one knows anyting of it...... they came up from sao paulo when the installed the system.... so let say we are in a bit of a prolem..... And the spare parts they charge much much more for here.... it would probebly be cheeper to bring in someone from england to repair the system here......

[Thermatech]

Well
If you want to have a go

Option A
1/ Get a service manual
2/ Compare the inverter circuit components one by one with the same components in the working systems as a comparison.Swich off power & disconnect all cables from each component to carry out the measurements.
I think you will find the inverter circuit & components are the same for all the large Set Free systems.

This way you should be able to identify which components are required.
Remember it takes a few mins for the capacitors to discharge.

Option B
Order all the inverter circuit components & replace them all as fail safe method.

[Coral Plaza]

We are going to try this..... another question... we have disconnected the first compressor so the system works but we have to have 10 unit runing all the time just to get it to work so the other compressors start. Why is that? i there something we have missed?

[Coral Plaza]

Well we have checked all the components with the working unit and the not working unit and the all have the same readings.... we checked the ground to every ph again and now we got 230 volt (before 0) but between the ph there was still 0 volt.

So all the components are working
We have power in to the inverter (230 volt ground to ph and 380 volt ph to ph) and we have ground to fas power (230 volt) but no ph to ph power on the outgoing connector to the compressor number 1.

Does anyone have any idee what the problem might be?

[Coral Plaza]

I really need some help with this problem.... don't anyone have a good idee?

[Thermatech]

To fully test ISPM it has to be completly disconnected & then 24 seperate resistance readings taken with analoge meter.

All as described in service manual.
What did you find ?

[Coral Plaza]

Everything was ok exept the RB to N witch is ok for high resistens but goes low when you change polaritys however i belive the manual is wrong witch states more then 90 kohm for both polaritys, we compared it with a working unit and it showed the same result. Every reading was the same as the working unit exept that we didn't have ph to ph power (380 volts) but we had 220 between ph to ground.
All the components showed the same results as the working one.

[Coral Plaza]

Do the ISPM inverter for the RAS 30 SF have a safty trigger for spikes in the current? if so do we need to reset it after it has been triggerd?
Might it be a problem with clogging of the heat Exchanger? We are thankfull for any idees on the problem.

[SkyWalker]

why is it "must" not to use a digital meter?

[al]

latest tech bulliten says you can use a digital meter, coral the ispm will still be under warranty, i,ve replaced one last week on a ras6, showing similar symptoms, working fine now.

al

[Thermatech]

Most A/C manufacturers will suggest use analogue meter for testing 3ph inverter circuit components in the service manual so all quoted readings in the service manual are based on the use of analoge

You can use digital meter but you dont get acurate readings because its not ideal for measuring semi conductor components.
older type analogue meters are better suited for this type of measurments.

Different multi meters will all give slightly different readings depending on the meter specification & internal circuits configuration.
If using a multi meter you will often get better readings with diode mode instead of ohms mode.
But as the manufacturer quotes analogue ohms readings you cant get like for like using diode mode as the readings will be completely different.

For example in the Hitach service manual in inverter testing section it states 'do not use digital tester'

I spent some days in 2001 at the factory in Japan which makes Mitsubishi Electric City Multi VRF outdoor units. The R&D inverter engineer was absolutely adamant
that IPM & rectifier components should only be tested with analogue meter.

[al]

Coral/Thermatech

PM me and i'll send a copy of a bulletin received in June this year, happened to coincide nicely with our first major component failure in 5 years installing Hitahci!!

al

[Coral Plaza]

Well we have done nothing but we got back the current on the phases.....
Why is that? is it a sensor that is the problem?
Before we had current between ground to phas but no current between phases. I went up yesterday and checked it again and now we have current between phases, well now we would like to test this but the first compressor need warm up time for 24 hours.... we read in the service manual that you could start the compressor cold but it did not say how to do this. So my question is how do we do that? we can not wait 24 houres because we have guesst in all the rooms.

[Coral Plaza]

I found the settings in the service manual :) just needed to read some more....
The temprature is now 37 C and the compressor should kick in at 40 C so if i do not use the coldstart how long time would it take for the compressor to go from 37 C to 40 C and start?