Generator auto shutdown

A discussion on another thread got me to thinking about my generator and it's auto shutdown system.

I've had my genny auto shutdown twice, both times for a clogged strainer due to sea grass. I don't think there's anyway to reduce this problem except not to anchor where sea grass is evident. I just hope the auto shut down occurs way before damage to the engine occurs. I've seen steam coming out of the raw water discharge a couple of times due to a clogged strainer but I guess the temp had not got to the shut down temp.

I could install a raw water temp alarm but have been relying on the auto shut down feature. We use the AC a lot in the summer in FL, so many times it runs all night.

Thoughts?

Add a flow switch to the shutdown circuit.

obthomas said:

Add a flow switch to the shutdown circuit.

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Or a raw water temp alarm which would be easier. Just thinking that the auto shut down is enough??

What gennie do you have? Most have a high temp switch on exhaust already.

How about installing a bigger strainer in a location with good visual and physical access? Check every 8 hours or so and clean as required.

Some day your emergency shutdown may not work,

Ski in NC said:

What gennie do you have? Most have a high temp switch on exhaust already.

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Westerbeke, maybe it is a raw water alarm, I just assumed it was a coolant alarm. Maybe both, I need to check, though I have not seen any wires coming from the exhaust plumbing.

sunchaser said:

How about installing a bigger strainer in a location with good visual and physical access? Check every 8 hours or so and clean as required.

Some day your emergency shutdown may not work,

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Good idea, but how big is big enough?

An in line water flow alarm is easy to install and will give you notice long before the generator starts to overheat.

I would not rely upon the overheating alarms on the Westerbeke for repeated shutdowns. Even if the the alarm works you are allowing the temperature to go up by 20 degrees F. Not good.

About or as large as your main engine strainer I would think.

Capt.Bill11 said:

About or as large as your main engine strainer I would think.

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install a eel grass strainer on the intake on the bottom of the boat????? did that with great results

capt jerry said:

install a eel grass strainer on the intake on the bottom of the boat????? did that with great results

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The problem can be the grass that is more like spaghetti size. It gets right through a intake screen. Of course sometimes the intake strainer holes themselves can get plugged up.

If your willing to pay for it Groco can eliminate raw water blockage concerns.
Groco makes what they call Hydromatic Self-Cleaning Raw Water Strainers.
They are either 12 or 24 vdc. They have a programmable timer.
And they can protect the entire boat with one unit.
Engine, generator, AC pump, wash down pump, etc.
The unit is a raw water strainer with a programmable garbage disposal unit to suck up, chew up and spit out any and all debris.
Sound too good to be true?
Check it out.
(And no I do not work for them.)
Groco 970-1500
Groco.net

Here's the data sheet on the unit. There is another one that has an even larger raw water intake range.

Pgitug said:

Here's the data sheet on the unit. There is another one that has an even larger raw water intake range.
View attachment 37820

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Amazing - what will they think of next!

A flow alarm is probably cheaper and easier to install. Would I install it on the intake or exhaust side?

Don't over think this. The factory high temp switch on exhaust mixer and factory high coolant temp switch combine to give you plenty of protection.

I have to agree with Ski below, plus usually my ear catches a change in exhaust sound.

Ski in NC said:

Don't over think this. The factory high temp switch on exhaust mixer and factory high coolant temp switch combine to give you plenty of protection.

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I can see when my generators exhaust is starting to get clogged up long before it shuts down.

Normally you cannot see any exhaust from my generator.

When you can start seeing steam coming from under the swim deck its time to unclog it.

Out main problem, and I'm fixing it this spring is that there is a 1" bronze 90 at the strainer intake. I'm going to change that out for a 1" long radius 90. Hopefully that will allow the material to actually get to the sea strainer.

timjet said:

Good idea, but how big is big enough?

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I went from a 3/4 thru hull and strainer to a 1 inch thru hull and 1 1/4 inch strainer and the gen has not shutdown since. It's been 5 seasons.

ksanders said:

I can see when my generators exhaust is starting to get clogged up long before it shuts down.

Normally you cannot see any exhaust from my generator.

When you can start seeing steam coming from under the swim deck its time to unclog it.

Out main problem, and I'm fixing it this spring is that there is a 1" bronze 90 at the strainer intake. I'm going to change that out for a 1" long radius 90. Hopefully that will allow the material to actually get to the sea strainer.

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That's my problem too. Elbow from sea cock gets clogged. And the idiot designer made it hard to put a long radius 90 in there. That would be me.

Strainer is small stock Groco 3/4", it has plenty of capacity. No need to go larger in my case.

Ski in NC said:

That's my problem too. Elbow from sea cock gets clogged. And the idiot designer made it hard to put a long radius 90 in there. That would be me.

Strainer is small stock Groco 3/4", it has plenty of capacity. No need to go larger in my case.

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Ski that is the reason I went larger.