Northern Lights 5kw genset

[Tommee]

My genset has been sitting idle for 7 months & having just started it it is not giving any power. It was fine previously. I have read about flashing it & the manual says apply 12v to terminals K & J...simple but does anyone know where these terminals are? Are they on the voltage regulator or in the box where the AVR is? It also says to disconnect the AVR before doing this. Does anyone have experience of this & tips please?

[skipperpete]

Here’s the wiring diagram. [ATTACH]266624

[Tommee]

Thank you

[skipperpete]

Before flashing the field check the breakers and maybe check the carbon brushes if the end of your genset is easily accessible. If you do need to actually flash the field note carefully the polarity of the terminals, getting them wrong is bad. Also consider trying the YouTube technique of exciting the field with a cordless drill spinning a corded drill that’s plugged into one of your AC outlets.... I’ve tried this several times and its been successful on only one occasion (on a portable 2 pole genset)

[Tommee]

Many thanks Skipperpete, my earlier reply was cut short for some reason. Unfortunately the diagram you sent was too blurred to make out, I did google same diagram & it came out blurred too, but appreciate your time. I have found the 2 fuses J & K that the NL parts book refers to for flashing & have some brushes on order. Almost impossible to get to the end of the genset but will try!!! My local electrician....who would never get into the lazarette where the genset is.....says flashing is simple??? Going to start there. Thank you again.

[Tommee]

I have flashed the unit twice but still no power. checked fuses & all ok. I have brushes on order. This is probably a dumb question but I don't have electrical knowledge...would a faulty DC voltage regulator be causing this problem? It is situated in a nasty spot where it can get dripped on by salt water if the exhaust manifold leaks or by coolant when I have to empty the radiator. I try to be careful & keep everything clean but the genset is in such a tight area, almost impossible to service, that it's not easy!!

[phorvati]

It would be AVR. Not DC voltage regulator. It's expensive. So try that as last resort. Q

[Tommee]

Many thanks for that, still have brushes to fit & see what happens then. Guessed the AVR would be expensive!

[skipperpete]

Originally Posted by Tommee

I have flashed the unit twice but still no power. checked fuses & all ok. I have brushes on order. This is probably a dumb question but I don't have electrical knowledge...would a faulty DC voltage regulator be causing this problem? It is situated in a nasty spot where it can get dripped on by salt water if the exhaust manifold leaks or by coolant when I have to empty the radiator. I try to be careful & keep everything clean but the genset is in such a tight area, almost impossible to service, that it's not easy!!

Try flashing the field again but have a small load connected in one of the outlets, an AC fan or a light should do it.
You’re right in suggesting that the dc generator is significant, it provides the DC for the field via the AVR, slightly larger generators have an internal dc generator on the rotor shaft but there’s a chance that if the dc regulator is shot the field can’t magnetise but I don’t know for sure how Kohler electronics manage the DC, perhaps one of the electrically talented forum members might weigh in with some sage advice.
I try to not give remote advice about gensets because you can get dead real quick with just a slip of a screwdriver in the usually terribly cramped space where gensets live, I’ve had a few close calls myself despite being ultra cautious so above all else , take care.

[s/v Jedi]

Originally Posted by Tommee

Many thanks for that, still have brushes to fit & see what happens then. Guessed the AVR would be expensive!

I flashed my 6kW 60Hz NL which is the same as yours I think. You should use a battery and connect it to the leads of the brushes, not to any fuse?

Also, you can check your brushes with a multimeter. In resistance mode, put one lead to the brush terminal, the other to the metal trace that the brush pushed onto.

When you run the genset, with a multimeter on AC voltage, connected to the output, what voltage do you see? You should see something like 1-3V or so.

Flashing it was easy for me, didn’t disconnect anything that I remember. Edit: WRONG , did disconnect that connector from the AVR and used it to connect the 12V battery to the brushes.

The attachment from SkipperPete is clear to read.

[Tommee]

Just fitted the new brushes & now have power. Thankfully that was the power problem but now it doesn't like it if you load it with more than 14amp (water heater). If asked for more the engine starts to die but picks up again if you turn the second item off (battery charger)....????

[skipperpete]

That’s great news that it powered up, well done!
Low power after sitting idle for 7 months? ! ..... maybe give the fuel system a thorough checkup and put on a couple of new fuel filters and clean the air filter . When was it’s last full service and valve adjustment? There is always the possibility of a compression loss because of a stuck /leaking exhaust valve or cylinder corrosion ..... the downside of water cooled exhausts.
If a filter change makes no difference to the load carrying ability, take out the glow plugs and do either a compression test or a leakage test (but perhaps save that till after checking how much blow by it has)

[Tommee]

Thank you Skipper Pete for sound ideas. I had already done one of "my amateur services" on it prior to all these problems. New fuel filters, oil change, cleaned the air filter, changed the coolant, checked the heat exchanger, cleaned out the exhaust manifold (not exactly blocked but not great) & had the injectors serviced. I am about to get new glow plugs as it is proving pretty hard to start but it has never liked the cold & it's not warm here yet. You mention compression & I have read that hard starting is a sign of low compression so maybe that's it. Will have to get an engineer in I guess to check this. Valve adjustment was in the dark ages!!! On the fuel system I haven't dare touch the injection pump so maybe that needs a service if you are thinking fuel problems. Thank you again.

[skipperpete]

I was hoping for a dirty filter or a suction leak. If you do decide to adjust the valves make sure you use a new rocker cover gasket........ it’s possible to hydrolock the engine if the thin divider gets broken or dislodged..... not immediately but when you do the next oil change, assuming you refill via the valve cover and not the side filler.
It’s possible to do a very basic cylinder leakage test through the glowplug holes if you can get a compressed air supply of say 100 psi, but it’s possible to get a result with as little as 30 psi. Ideally you rotate the engine to TDC on the cylinder to be tested then lock the rotation with a socket wrench and breaker bar on the crankshaft pulley nut BUT I’m usually in a hurry and also hate the “ lock the engine” gig so I speed it up by turning the piston to BDC and loosening the valve adjusting screw till the valve is closed ...... then whack in the air and check the critical points for leakage ie,
1. Oil filler cap ( for cylinder and ring wear)
2. Intake manifold ( for leaky intake valves)
3. Coolant tank pressure cap( head gasket blown to water jacket)
4. Exhaust outlet ( for exhaust valve leaks, usually bubbling in the aqualock)
5. Check the other glowplug holes for air ( blown gasket between cylinders)
This is a very speedy test procedure and can be done with greater safety than the TDC method.
There should be little or no valve leakage but there will always be some cylinder leakage even on a healthy engine, it’s the severity that you’re trying to establish.

[Tommee]

Hello Skipper Pete, yeah, I was hoping for something simple that I could cope with! Thank you for the info, will try & get my head round it & get back in that lazarette