Fujitsu-General Fault

[saife]

ask your friend saife nex time

[nike123]

ask your friend saife nex time

What?......

[frank]

Not bad Saife

- it only took you 18 months to make a post - and then we don't know what you are on about.

Com'n, don't be shy!

[airefresco]

This job has surfaced it´s ugly head once again.

Apparently 2 other people have been since me and have "changed the boards". Whatever that means. The client reckons he´s spent 400€ so far, so I think they have just been changing the AFM boards.

Anyway, he´s asked me to sort it out. I gave him the option of changing the outdoor unit. He has said that this is fine, but if it does not solve the problem he is not going to pay me. Now this immediately put me off the job, so I think i´m going to tell him I´m not willing to do that.

What would you lot do? How big is the chance that the indoor unit could be at fault?

[paul_h]

zero chance of an indoor fault IMHO. As you said, the c/b tripped and the fan motor didn't seem right and it's run for a while when someone else has changed the outdoor PCBs.
Indoor faults in fujis are extremely rare, limited to a comms fault or power surge. An indoor fault would still be there and the system would never work no matter how many times the previous repairers changed outdoor PCBs.

All that being said, you'd really want to be making a lot of money to be bothered to take this task on. There's chances of the customer not wanting to pay for x amounts of days to make sure it works, and the small chance of getting a faulty new outdoor unit.
If you are worried about a possible fault with the indoor unit, don't worry at all.
If you are worried about whether the customer will pay, well then that's probably justified.
edit: as I've said before, they are pretty easy to troubleshoot. The posistor goes open circuit when theres a fault. It's easy to disconnect all the outdoor motors and get comms back on line when the posistor closes again. If you can get comms, the indoor has nothing wrong with it.

[airefresco]

Thanks Paul. I went today to see the guy to try and come to a compromise. I wanted a deposit for the price of the kit (2500€) more or less and pay my labour and gas etc when/if it works. But he doesn´t want to pay anything until it´s all working again.

I also noticed that the indoor unit is running. So yeah, it probably is OK. However, someone has taken the filters out and it has been running 24/7 since around February (apparently) without any filters in. The grille is really dusty/dirty, so I would hate to think what the coil is like. So with all that in mind, I´ve told them without a deposit I´m not intrested in doing it. The guy is really dodgy anyway.

On a side note about the comms thing- If the you disconnect the compressor and the fan motor, for example. The unit will run without any errors? So as long as the posistor is made, the unit will think everything is alright?

[paul_h]

With things disconnected it will cut out on error, you just get to see the unit power up and take any readings for a minute or so.

[airefresco]

Ah ok, Thanks Paul

[ozairman]

Hi Airefresco, if other people have changed the boards since last time the best solution is to assume nothing and start from scratch!

Also try and find out what "all the boards means" is there any info or obvious signs of what has been changed?
Start at the basics and ensure ALL wires and connections are connected as per the wiring diagram inside the cover.

The first thing to do is listen to the unit when you apply power to it, do you hear a "click" of the power relay on top R/H corner of the Power Supply pcb (front R/H side board).

If you do then the next thing you should hear is the EEV clicking and ticking and doing its initialisation sequence (drives fully shut then fully open).

If NO clicks and ticks then measure AC Volts across Posistor small orange wires W25-W26 below power relay, if 230VAC (your mains voltage?) is present then this indicates a SHORT CIRCUIT circuit downstream of this point (the Posistor itself will be hot/warm if has opened). If you measure about 6-10VAC across the Posistor then this indicates that the power relay is NOT being energised but voltage is passing through the posistor.

The function of the Posistor is to allow and limit current flow through the unit on powerup, in cases of short circuited components downstream the posistor will go open circuit and allow No Voltage through the circuit. Power must flow through the posistor initially as it is in parallel with the power relay and acts as a bypass so that AC power can get through the open relay contacts and onto the diode bridge.

At the diode bridge it is converted into DC voltage and then fed into the Active Filter module (ACTPM). The ACTPM does power factor conversion and boosts the DC voltage inside the machine (300-350 VDC in standby and 380VDC when compressor should be running). The ACTPM is controlled from the Controller PCB. From the ACTPM the HV DC goes to the Capacitor PCB and then feeds down onto the IPM PCB.

The IPM PCB takes the High Voltage DC and switches it to create "artificial three phase AC" to drive the compressor at various frequencies. The HV DC which is fed onto the IPM PCB is also tapped off here and fed to the Controller PCB.

The outdoor unit will not energise unless High Voltage DC is getting onto the Controller PCB (front left hand side) at CN200 DC Volt IN and the Low Voltage switchmode power supply section of this pcb is operating.
The challenge is for You to identify at what point the chain is being broken.

It is possible to disconnect the compressor and DC fan motor, but if the system has been operated with a short circuited fan motor or a compressor with an earth fault then both will cause damage to the respective PCB's they were attached to which means the machine may still not power up.

So make sure you test the compressor for earth faults using an insulation resistance tester/megger (500V) not a multimeter.

To test the DC fan motor you need to get familiar with the "diode check" function of your multimeter and test between the Red-Black leads of the fan motor and the White-Black leads of the fan motor in both polarities/directions. You should not see any short circuits or the same reading in both directions when you do these tests
For example:
Positive meter lead to Red and Negative meter lead to Black = OL or overload then Positive meter lead to Black and Negative meter lead to Red = 0.9V is a Good reading. If you have 0.1V on your meter in both directions then it indicates a short circuit and defective motor.
You will need to have sharp test probes on your multimeter to get to the connections at the side of the plug.

REMEMBER NEVER unplug the DC fan motor whilst the mahcine is energised as you will damage it and the pcb it is plugged into.

Check your PM's for more some info explaining this a bit better, I hope this hasn't confused you too much! Once you get your head around it inverters are not that bad to diagnose and it could become very profitable if you know what you are doing.

OzAirman

[airefresco]

Thanks for that information and your PM too.

[gianchi]

Can you send me the service instructions for ASH9LSACW/AOH9LSAC ? I have two faulty units to try to fix.
Thanks in advance, I'll appreciate it.

[capthummel]

Heard something today which may add a twist to this. Apparently the guy who installed the system is to keen on vac pumps. Been to another job of his today. Two Samsung units a little over 2 years. Both units with dead compresors. After a few phone calls, it turns out he wasn´t keen on lugging the vac pump around. I might just go for a new outdoor unit now knowing this, or least give the client the option to do so. Great eh.

Seen this same problem before and also was told by some fool that you do not have to vacuum down a precharged system. Acid test it bet it is full of contaminants. Allot of interesting problems out there with these precharged ac's and compression fittings. Also I have found plenty of crap component problems with fujitsu.

[carloscuba]

hola a todos -tengo una averia en un equipo fujitso general AOH24lmarkl se an disparado los termicos y al retasblecerlos me da error de comunicaciones, alguien me puede ayudar a conseguir los planos de este circuito

[airefresco]

Carlos - No puedo ayuadate con el problemo, excepto el sitio elaireacondicionado.com tiene un forum en español y hay tecinos de fujitsu ahí.

To the none spanish speakers - Basically he wants a circuit diagram for the above model, as he has a communications error.

[nike123]

........................

[nike123]

We need full model names for indoor and outdoor unit!
AOH24lmarkl is not correct model name.

[airefresco]

Carlos - El modelo que da no estar correcto. Necesitamos el modelo actual de la unidad interior y exterior.