How to flash 9kW Fischer Panda generator

[dsolded]

I recently removed my 9kW Fischer Panda generator to have the engine rebuilt. The generator now starts and runs nicely, but the generator does not produce electricity. My web research suggests the generator needs to be flashed. Does anybody know the safest way to do that without damaging the alternator end of the generator. This is a 240VAC generator, with one 240V leg, not two 120V legs. Thanks.

 

[Boater Sam]

Is this a permanent magnet generator, AKA dynamo? Unlikely, so flashing to magnetise the core is very unlikely.
Much more probable is an assembly fail.

 

[William_H]

If you want to flash the generator to get some permanent magnetic field needed to provide some output of which is used to provide the real controlled field current ...
You need to identify and access the field coils. Probably the rotor connected by brushes (slip rings). Identify if possible which slip ring carries positive field current and which carries negative. Disconnect the wires, regulator to slip rings and connect a 12v battery momentarily to the slip rings hence to the field coil which will provide some permanent magnetism to the rotor. This is known as flashing because you only connect the power momentarily. It may well spark.
This procedure is usually only necessary if permanent magnetism is lost perhaps from dismantling. Once up and running the magnetism will remain until next used.
If the rotor has been removed from the alternator (generator) then it may need to be flashed. Still quite unusual to need it. Perhaps check wiring etc first. (especially condition of slip rings and brushes.) All from someone who has never seen a Panda generator ol'will

 

[QBhoy]

You’d imagine it’s more likely a windings or insulation failure? Do you have access to a meggar?

 

[VicS]

I recently removed my 9kW Fischer Panda generator to have the engine rebuilt. The generator now starts and runs nicely, but the generator does not produce electricity. My web research suggests the generator needs to be flashed. Does anybody know the safest way to do that without damaging the alternator end of the generator. This is a 240VAC generator, with one 240V leg, not two 120V legs. Thanks.

Assuming everything is reconnected correctly and your Web research is correct see if there are instructions for testing the windings and
"Rotor Magnetism Loss and „Re-magnetising"
in the owners manual.

I've found them for the 8000 on line. Maybe the 9 kW generator is similar

 

[Alex_Blackwood]

If you want to flash the generator to get some permanent magnetic field needed to provide some output of which is used to provide the real controlled field current ...
You need to identify and access the field coils. Probably the rotor connected by brushes (slip rings). Identify if possible which slip ring carries positive field current and which carries negative. Disconnect the wires, regulator to slip rings and connect a 12v battery momentarily to the slip rings hence to the field coil which will provide some permanent magnetism to the rotor. This is known as flashing because you only connect the power momentarily. It may well spark.
This procedure is usually only necessary if permanent magnetism is lost perhaps from dismantling. Once up and running the magnetism will remain until next used.
If the rotor has been removed from the alternator (generator) then it may need to be flashed. Still quite unusual to need it. Perhaps check wiring etc first. (especially condition of slip rings and brushes.) All from someone who has never seen a Panda generator ol'will

Agree with all that, absolutely. However only requires lifting the brushes, no disconnection needed. Depends how, and for how long, the alternator has been stored during engine rebuild, could account for loss of magnetism. I have seen it happen.
There is some stuff on U-tube about flashing alternators. One guy connects a drill and gives it a spin by hand !! Might work??

 

[ashtead]

You might just have to flash more cash ? Surely the rebuilder of the unit might be a more reliable source of guidance as you might end up damaging what has a reputation as a somewhat fragile unit ?

 

[VicS]

See Section 8 , Generator Faults in the manual here

Fischer panda 9000 Manuals | ManualsLib

8.8.1 describes re-magnetising:

8.8.1 Rotor Magnetism Loss and „Re-magnetising"​

See "Safety Instructions - Safety First!" on Page 19.​

ATTENTION!​

In the case of asynchronous generators, the generator cannot independently increase voltage after standing still, or,​

if it is switched off under full load. This is because the rotor has lost its remaining magnetism.​

This remaining magnetism can be restored simply by use of a DC battery. In addition the „shore power" must be​

switched off and any connection to an AC-source must be interrupted.​

Likewise the generator must be switched off, i.e. also the starter may not be operated. The power source selector is​

switched to „generator". Only the plug socket must be connected with the generator.​

Now the two poles of a 9 Volt battery are connected to the plug socket or held against the appropriate contacts of the​

on-board current distributor. Do not use a battery bank or the generator starter battery, this could damage the​

winding. The DC voltage only may be applied for a short time (1-2 seconds). In the winding the remaining​

magnetism is restored by a short current pulse, and the generator can normally be started​