Fischer Panda generator issue - where to start?

[alexincornwall]

Hi all,

We have a Fischer Panda P6000 6kW generator onboard - 580 hours, annually serviced, always run under load and never knowingly over loaded.

During a recent cruise it became apparent that the generator was audibly struggling under load with engine speed reducing to a point where it sounded as though it was on the verge of conking out (it didn’t, but didn’t sound very healthy so I shut it down). All the time the gen set was running fine and producing approximately 230V at the panel without any load applied. My initial suspect was a defective immersion heater element (2 kW unit), which appeared to be exacerbating our symptoms more than any other high-draw appliance. I have swapped this out (posted about that in June), a surprisingly tedious operation based due to space constraints but our problem remains.

Our water is heating, but not as quickly as it should/had been. We’re still getting around 210V at our sockets so whilst everything is technically working, something feels amiss. I have had a little fiddle with the actuator as the idle speed seemed a bit low, but no real improvement when a significant load is applied - immersion, wife’s hairdryer, coffee machine etc.

Our fuel is clean and the filters are new. Air filter also looks good.

Whilst the generator had been running perfectly until recently, we have had a couple of minor issues this year and I wonder if there could be a connection:

- At last service it was noted that we’d lost a single impeller blade. The unit was not over heating and visibly/audibly producing the intended quantity of raw water at the exhaust so the decision was made to leave for the time being (the heat exchanger is on the bottom of the generator and will require full unit removal to get to – we’re simply not reliant enough to undertake mid-season).

- I had to replace a corroded raw water intake hose which had leaked, causing some connections in the gen set to get wet. This was dealt with very quickly and there are no visible signs of corrosion/damage.

Where should I start please? I’m definitely not a generator aficionado but would like to see if I can resolve myself as engineers are like hens’ teeth at the moment. I am mindful that I’m playing with AC currents here…

 

[superheat6k]

Exhaust valves - these sit permanently above what was hot very salty, partially evaporated seawater and suffer corrosion of the valve seats.

Invariably once corroded the valves and seats will need replacement, but it is where I would start, rather than finish, but it does require the cylinder head removed. As yours is 6kw I expect you will have a two cylinder engine and it will not be made by FP, so avoid going to FP for parts.

 

[alexincornwall]

Thanks @superheat6k that's interesting. I'd considered that I was looking at an electrical issue, not mechanical. If a cylinder head removal is required, that's not a job for me to take on myself.

 

[Ian_Edwards]

It looks like the P6000 uses a Kubota Z482 twin cylinder diesel engine.
It asynchronous, so the frequency and voltage are determined by the electronics. The output from the generator (really an alternator) is likely to be 3 phase variable frequency at around 400v, which is then rectified to DC, and finally inverted to 230v AC 50Hz.
Do you know if the system is still working at 50Hz? If it is then and you are only getting 210 v AC out, that sounds to me like a fault upstream of the inverter.
Could be:

• The engine not producing enough power or revs.
• There's a fault in the generator, it's not producing a high enough voltage, not enough field voltage?
• There's a fault in the power control circuits?

Without knowing to much about the engine, if it is the valves, as suggested, wouldn't a compression test be the first thing to do?
If the compression is low, then then the generator may be having problems producing enough power.
It seems, from a quick Google search that the Kubota Z482 twin cylinder diesel engine is relatively common, so you may well find a non marine engineer who knows the engine and can help.
I would steer well clear of Fisher Panda UK, I've had 2 of there generators and both where more trouble than they were worth. Both where Asynchronous, and I had failure in the rectifier/inverter system on both. The electronics had to be removed from the engine and sent back to Germany for repair, a process which took months. In one case, I was told that the unit was obsolete and not repairable, despite it being only a few years old. I had to buy a new one!

 

[Ian_Edwards]

I just loaded the manual for the P6000, out of interest.
There's quite comprehensive fault finding procedure, with a section covering low voltage.
It's worth a look, if you don't have the manual, I used this link:
https://fischerpanda.com/Manuals/Panda 6000ND Operation Manual.pdf
It works through the possible fault which cause low voltage on page 40.

 

[alexincornwall]

It looks like the P6000 uses a Kubota Z482 twin cylinder diesel engine.
It asynchronous, so the frequency and voltage are determined by the electronics. The output from the generator (really an alternator) is likely to be 3 phase variable frequency at around 400v, which is then rectified to DC, and finally inverted to 230v AC 50Hz.
Do you know if the system is still working at 50Hz? If it is then and you are only getting 210 v AC out, that sounds to me like a fault upstream of the inverter.
Could be:

• The engine not producing enough power or revs.
• There's a fault in the generator, it's not producing a high enough voltage, not enough field voltage?
• There's a fault in the power control circuits?

Without knowing to much about the engine, if it is the valves, as suggested, wouldn't a compression test be the first thing to do?
If the compression is low, then then the generator may be having problems producing enough power.
It seems, from a quick Google search that the Kubota Z482 twin cylinder diesel engine is relatively common, so you may well find a non marine engineer who knows the engine and can help.
I would steer well clear of Fisher Panda UK, I've had 2 of there generators and both where more trouble than they were worth. Both where Asynchronous, and I had failure in the rectifier/inverter system on both. The electronics had to be removed from the engine and sent back to Germany for repair, a process which took months. In one case, I was told that the unit was obsolete and not repairable, despite it being only a few years old. I had to buy a new one!

Thanks Ian,

I've also since read that FP generators aren't much to write home about but not much we can do as that is what we inherited with the boat. I spoke with an engineer that'd been recommended this morning and he smirked when I told him our brand! A shame because it's given us years of reliable service up until now. I have to say that I'd initially dismissed the usefulness of a gen set but now we have one, wouldn't want to be without.

I've taken a look at the manual but wanted to see if anybody had first hand experience of the same problem before getting stuck in.

 

[andwoo8182]

Did you progress with your fault finding at all?

I inherited a FP 4000s genset & am quickly learning of the exhaust valve issues & the need for a proper wet exhaust system install. My generator wasnt starting, only turning over, and showed a lack of compression. The exhaust valve clearances being set got it running, but that quickly became needed before every start, leading me to take the cylinder head off which showed the recessed exhaust valve - and following the various threads on the topic here, it certainly seems to be the same corrosion related issue that many others have experienced.

I'm not experienced with any of this, but followed the manual for disassembley & learnt plenty along the way.

So I'm off to get the valves/valve seats replaced before putting it back together & planning a fresh water flushing system for the raw water cooling, along with some robust winterisation tactics.