Generator Frequency

[jespchee]

Thanks to all on my post of the propeller issue, as the engines' temp. quickly increase at the 2100 rpm it indicates to me of overload, I will try the 3-blade ones. Now for my next issue. The generator is a Northern Lights M643-4.5N. So for what ever reason the PO has been running this generator at a setting of 50 Cycles. This apparently reduces its capacity quite a bit and can damage certain pieces of equipment. The manuals show this generator can be at 50 or 60 cycle depending on rpm. I can however not find anywhere on how to set the rpm to the 1800 rpm required for the 60 cycle. I have reached out to several northern Lights contacts I found on the web but so far no response. Any ideas- Thanks

 

[kchace]

Looking at the parts manual for it there looks to be a governor lever on the side of the timing cover that may be adjustable. I'd just be extremely careful doing it without a manual.

Ken

 

[Boat]

Do you have manuals for your generator? You can download some.

https://www.northern-lights.com/technical-information/manuals/#1495060964854-77e74ee4-a801

I remember 50 cycles as being used for European and military stuff.

 

[Lepke]

The injector pump governs engine speed. It needs to be set for 1800 rpm. Commonly on the injector pump there is usually a lever with 2 locked set screws. One for idle and one for running rpm. With the engine stopped the lever should lean on the idle screw. With the engine running and a hertz cycle meter you adjust the running screw until the meter reads 60 cycles. Then lock the screw.
Your injector pump should have an id plate with the makers name and the model number. You might find a manual online. Injector pumps are rarely made by the engine maker.
Attached is a parts manual that includes your engine.

 

[Captain Ralph]

Before anything. How are you sure it's making 50 htz? How are you sure it's turning 1500RPM? Thinking that lil giffy analog meter on the console is accurate?

Have you the correct strobe tach, palm tach, freq meter on hand?

 

[jespchee]

Thanks to all. Will investigate more in detail once I'm back at boat. The cycle issue was picked up by the surveyor using his frequency meter. Conversations with PO stated it was 50 cycle and he had set his inverter to the same frequency. That's a simple fix with the inverter and I have just purchased a quality frequency/VOM so should be good to go. Will keep you posted.

 

[DavidM]

Ski of NC knows these generators well, and hopefully he will chime in here. Changing the RPM should be fairly easy as I suspect it is just a throttle adjustment. But also check the voltage before and after changing the RPMs at various loads. With capacitive regulation it can make a big difference, although I believe that the NL uses a more sophisticated (but non electronic) form of voltage regulation, so it may stay fixed.


David

 

[Ski in NC]

If it was originally purchased as a 50Hz Euro unit, there are some differences in voltage regulation. And it does have an electronic voltage regulator. Euro is typically 50Hz/220Vac. Stateside is 60Hz/120Vac, but can also be wired for 60Hz/120/240Vac if some of the boat loads are 240V. Most of these little machines are simple 120V.

Setting governor is easy, lever right in front of injection pump with two set screws, just adjust til freq gets to like 61Hz unloaded. But before powering up anything on the boat, check output volts to make sure it compatible with your boat.

Something is very strange with setting a stateside gennie to 50Hz. I would want to fully understand the "why" before changing anything.

What kind of shore power connection do you use? Single 30A, double 30A or 50A? Pretty much any boat with 30A cords is simple 120V.

 

[jespchee]

When PO rewired boat shore power input was reduced from two 30 amp connections to one.

 

[tiltrider1]

Just talked to Scott dybald the service rep for northern lights. He wants you to get the serial number off the generator and call him direct. Once he has the serial number he can look up the as builds and talk you through it. He says if it was wired 60hz and its dropped it's a speed screw adjustment. If it is a 50hz spec generator then more adjustments are required. You can look up northern lights number on google.

 

[DavidM]

I totally agree with having a conversation with someone knowledgeable about NL generators at the factory. But let me expand on the voltage implications.

I have got to believe that both US and Euro NL built generators use the same generator end, just wired differently. The generator has an output coil that produces 220/240 (the two are effectively the same so think of them as one value) and has a center tap that produces 110/120V from the tap to the other ends of the coil.

So to produce 220/240 in Europe or for a US boat that only needs 220/240 (not any that I can think of) you just wire to two ends of the coil to the 220/240V panel and the generator will produce 30 amps at 220/240. I am just using 30 amps to illustrate. The 5KW generator will produce less.

If you need just 110/120V then you parallel the two phases of 110/120V and you get 60 amps at 110/120V.

But some US boats need 110/120 as well as 220/240. So you wire each leg of the 220/240 to the panel as well as the center tap as a neutral, just like you home's electrical panel. Such panels have two busses, one for each leg of 110/120 that are supplied by each leg with the neutral (the one coming from the center tap of the generator coil) supplying the other side of the 110/120 circuit. In this case you cannot combine the two 110/120 circuits to produce more current. You are limited to 30 amps on each leg.

So talk to NL about what is going on. You probably need to do three things: increase the rpms to get more hz out of it, deal with the voltage regulation issues, and rewire the generator output to produce double the current for 110/120V. The latter may not seem important if one leg fills your needs, but doing it is easy and will be easier on the generator windings.

Sorry, this has been long, tedious and a combination of layman terminology and electrical terminology.

David

 

[jespchee]

Ok I talked to Scott (thanks for that tip) have solution. Check voltage regulator, depending on model may have to move dip switch from 50 to 60 and then increase frequency to 60. He recommended setting it at about 62 cycles to allow for a small drop under load. Just thought I would put that out there in case anyone else was wondering. Again thanks to everyone, this is a great place to solve one's boat problems,- G