Fischer Panda genset - acceptable operating temps? Auto shut downs

[MondayNever]

Good afternoon,
I've got a ~2006 FP 6000ND PMS 240v/50hz genset with ~1200 hours. During my two year ownership I've only run it for ~20 hours or so and I've put in at least as many hours troubleshooting it for various issues. The current problem is intermittent rev downs and automatic shut downs while running at low to moderate (0-3.5kw) loads. Overheating is the initial suspect, but the pattern is not obvious.

- Engine shuts down anywhere between 15mins and 2hrs after a cold start.
- Load is variable, but does not seems to directly correlate to length of run time
- T.-Engine (engine temp) fault light usually comes on at the time of the shut down event, but not always
- T.Wind (AC winding temp) fault light has come on twice causing a shut down after switching off all the loads after a successful run for the recommended 3-4 min cool down period.
- Sometimes no fault light comes on the panel at all during/after a shut down
- The engine intermittently revs down before coming back to full RPMs as though fuel supply has been temporarily cut. Usually no fault light when this happens.
- The coolant temps have been anywhere between 185 and 205 when this has occurred

I have gone over much of the cooling system to ensure good operation. New waterpump and impeller, cleaned strainer, no obstructions at through hull, recent back flush of raw water side to get out old broken impeller blades, fresh coolant free of air, etc. The only thing obvious left to suspect is the (inaccessible) heat exchanger that could possibly benefit from a barnacle bust session.

But this all assumes that the motor is actually overheating. What are the acceptable temperatures at different points in the engine/system? I'm seeing coolant temps at the expansion tank usually at 195*F but occasionally going above 200*F. Shooting various points around the engine I'm seeing temps in the 220s, even 230s. That seems extremely hot to me, especially compared to the big old Perkins 135 main engine, but I don't actually know and I have no baseline prior to the problem starting. Before I go any further troubleshooting the cooling system, can someone tell me what kind of temps they are getting on their FP unit?

Thanks!

-Will

[djs]

As others have not jumped in with the answer you were after…
I can’t help with the figures for temperature as we don’t have the means to measure that on our FP 4000s.

But, as the coolant flush is the one thing you haven’t done yet I suggest doing that. I know you said you have replaced coolant.

We recently had an overheat and the gen shut down automatically. It was a duff impeller but in changing that decided to remove and flush the heat exchanger. That side was all ok but we then didn’t have coolant flow. The expansion tank outflow was blocked. I suspect that in disturbing a lot of the coolant pipework we loosened up a lot of debris.

Many, many flushes using just water removed lots of dirt and rust. A citric acid flush removed even more. It’s now running smoother and (seemingly) cooler.

We use the trick of removing the oil pressure sensing wire with the power supply turned on so the water pump runs and circulates cooling water to do these rinses / cleans.

Good luck
Dave

[Cheechako]

A repetitive issue with the Fischer Panda for many many years now.
If I had one, the first thing I would do would be to take off any of the Automatic shut down etc controls and make the unit all manual control other than rpm.

[svHyLyte]

Firstly, I suggest you use an infrared thermometer to measure the temperature of your exhaust manifold at the point the machine shuts down and compare the results with the temperature range stipulated in the manual for your machine.

Further, while you think you have cleaned the raw water side of the cooling system, merely back-flowing fresh water through it and flushing it out does not remove crusty build-up and barnacles that will develop during long idle periods. To ensure the system is "clean", you need to recirculate a mixture of Barnacle Buster (or equal) through the system for several hours to dissolve any build-up on the surfaces of the system followed by a fresh water flush. You'll be amazed at the amount of additional debris that washes out. See one or more of the prior threads on FP generators for instructions on rigging a small submersible bilge pump in a bucket of solution to flush your system.

Like-wise, given the hours on the system with long periods of inactivity, you may have debris build-up on the coolant/fresh water side of the system. For this you'll need a flush similar to the flush of the raw water circuit in this case, however, using the coolant pump on the engine itself to recirculate the solution. For this the coolant return line to the pump is disconnected at the pump and, with a temporary extension tube, directed to a bucket of solution. A similar tube from the solution bucket is connect to the pump input fitting. WIth the generator panel "On", and the oil pressure sensor pug pulled free of the pressure sensor, the coolant pump will activate and recirculate the cleaning solution. Let that run for an hour or so and than replace the solution with fresh water. Similar to the raw water side flush, you'll be amazed at the crap that washes out. Once you've done that exercise, disconnect the temporary return tube and let the cooling circuit drain down. Then, reconnect the engine coolant return to the pump and refill the cooling system with coolant via the return/expansion tank (remember to loosen the little bleed screw on the top of the heat exchanger body to ensure that the system fills properly.

With both the coolant side and raw water side of the system cleaned out, you should be good to go.

Further, as for FP gensets, the adage to remember is "Use it or Loose it." To keep things "nimble" you need at least 10 hours of run-time per month.

BTDT. FWIW...