Hunter 460 - Northern Lights Generator

[Ed M.]

I have a Northern Lights generator (6KW) that has stalled consistently with just the water heater and refrigerator running off the AC power. Over time I have come to find that the stalling first occurs because the through hull opening gets clogged with weeds and even a jelly fish.
If this happens too often the impeller legs break off from heat and then begin create a clog near the heat exchanger. This can be then fixed by cleaning the clog and installing a new impeller. But then he cycle then starts again.
I am pluzzled as engine has a somewhat larger through hull opening and strainer and I never( knock on teak) have the same issue.
Should I just install a larger through hull opening and larger strainer? Does this seem logical? Has anyone had a similar experience with a Hunter 460 or other boat?
Thanks.

 

[Buck420]

I have the same generator and set up on my '01 H420.
I've had the same problem you describe, but only once. It hasn't been an ongoing issue for me.
I ck my raw water strainer frequently and try to keep it clean.
If I were having as much of a problem as you are, I would first replace the small strainer w/ the larger (engine size) strainer to see if that helps assure adiquate raw water flow thru the gen. The gen thru hull IS smaller than the engine thru hull; but apparently is supposed to be able to provide sufficient water flow.
If the problem persists, I would consider removing the generator heat exchanger and having it boiled out and cleaned at a radiator shop.

 

[Persy]

I have an 01 420 and have had quite a few problems with the same setup, exactly as you describe. Run generator, pull in seaweek or jellyfish, restrict water, break impeller, clog heat exchanger, etc etc.

I have upgraded the intake strainer to an engine sized one. This has significantly reduced the frequency of the problem, but does not eliminate it. The intake seacock, hole, & hose are just too small for the volume of water and I regularly end up with the sea grapes or jelly fish jammed in the hose and seacock. The strainer itself clogs as well with sea grass or jelly fish.

I'm now considering adding an external screen, but know there are problems here as well.

If you come up with a solution, please post it.

good luck!

 

[Bryce22345]

I had a similar problem with my Fischer Panda. I had a 1 inch thru hull which immediately stepped down to a 1/2 line to the strainer. sometimes I'd suck up sea weed etc. in minutes. changed everything over to a 1 inch line from the thru hull to the strainer and then reduced to the line 1/2 inch after the strainer and have been fine since. my theory is that there is a venturi affect created outside the hull because of the speed the water had to flow. increasing the line size effectively reduced the speed of the intake water at the thru hull, thus reducing the venturi effect. worked for me.

 

[Bill Bell]

I too have problems with the weeds being pulled up and clogging the system. You just have to clean it out periodically.

I noticed that you said that you run the generator just to make hot water and run the refrigerator. You need to keep a heavy load on the generator or you will carbon up the valves and clog the exhaust elbow. Been there, done that. I now make sure that I have plenty of load when running the gen set. This includes running heat or air when not needed, just to load the generator. My bill to repair the gen set was $1900. So I think that I can afford to use another couple of gallons of diesel fuel a year to keep it running.
Bill