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Old 11-26-2019, 09:33 AM   #61
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my panda packed up, contact the maker in the UK, they had a recon, bought it and fitted in with no hasle. good luck
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Old 11-26-2019, 11:11 AM   #62
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Please splain your reasoning here. Thanks

“one change i made on both is to make rw cooling a 110v a/c pump. it basically moves rw from the genset area.”
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Old 11-26-2019, 12:33 PM   #63
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a common mod...get rid of on engine raw water cooling because of expense and dangers/issues of salt water around a genset by using a 110 water pump hooked to the genset to start pumping when 110 is activaed. Usually an air conditioning pump is the replacement.
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Old 11-26-2019, 12:40 PM   #64
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I have a Next gen 5.5 in my GB42. It is over 10 years old and has been installed for 5 years. I have 1200 hours on it. I bought it from a gentleman that bought it new but never installed it. It has the herringbone drive belt and a Markon electrical head. The newer ones have a serpentine belt and I believe a Linz generator head. It has had some issues but I was always able to get to talk to a real tech in Jacksonville and get it resolved. All the issues I have had seem to be addressed in the newer model. While I didn't get a sound enclosure, I wish I had.
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Old 11-26-2019, 03:46 PM   #65
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a common mod...get rid of on engine raw water cooling because of expense and dangers/issues of salt water around a genset by using a 110 water pump hooked to the genset to start pumping when 110 is activaed. Usually an air conditioning pump is the replacement.
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Old 11-26-2019, 07:46 PM   #66
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a common mod...get rid of on engine raw water cooling because of expense and dangers/issues of salt water around a genset by using a 110 water pump hooked to the genset to start pumping when 110 is activaed. Usually an air conditioning pump is the replacement.

I've installed 110AC pumps on generators but it was a hassle. The pump has to be below the waterline and a check valve is needed to keep the prime.

Loses prime from time to time. Too many issues.

Used a March AC pump.
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Old 11-26-2019, 07:54 PM   #67
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I've installed 110AC pumps on generators but it was a hassle. The pump has to be below the waterline and a check valve is needed to keep the prime.

Loses prime from time to time. Too many issues.

Used a March AC pump.

As long as it is below the waterline a check valve shouldn't be necessary.


Lots of people have done it and consider it a "great mod".


I have considered it myself...and if I ever install a new genset...it will be done that way.
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Old 11-26-2019, 08:36 PM   #68
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our entec guy turned me on to it. yes we need a check valve because the bow of our pdq would crest a wave and expose the thruhull but i'd never go back.

i installed the same on our nextgen/mainship. that was tougher. genset is just above waterline with shallow bilge, but i finally got it working. after having a shaft seal go and spray saltwater everywhere i'd still do the 110 pump.

but heh, everyone has their favorites.
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Old 11-26-2019, 10:30 PM   #69
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Idea of installing a separate water pump is new for me, and seems bizarre. I'm in the process of installing a northern lights 6kw so would like to hear more.

How is ane electric pump that turns on when engine is on better than an engine mounted impellor pump that turns on when the engine is turning? Engine mounted raw water pumps seem pretty reliable, no? What am I missing?
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Old 11-26-2019, 11:07 PM   #70
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The 110 volt pump for generators was developed by Entec for their generator which had the raw water and coolant pumps on the same shaft. The two sides are separated by a seal which when it fails resulted in salt water mixing with the coolant.

Entecs 110 VAC pump system used a March pump and an industrial check valve. The check valve kept the system primed.

The 110 VAC pump is a centrifugal pump so it doesnt have enough positive pressure to fill the engine if unprimed. Any debris in the check valve kept it from shutting completely resulting in the water draining down and required repriming.

If a vane, gear or impeller pump is utilized, the priming issue may not be a problem.
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Old 11-27-2019, 06:39 AM   #71
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First, no impeller to burn up or seal to leak when the run dry (bag, jellyfish, systems like mine that tend to drain in some seas)....


Some gensets have belts to worry about/adjust.


Pump is less than half the cost than an OEM/aftermatket for some gensets.
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Old 11-27-2019, 07:14 AM   #72
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in addition, the pump is wired to the genset 110v output. the pump doesn't pump water until the genset actually starts. it eliminates the possibility of filling the muffler and backfilling cylinders.

on another note, both the entec and nextgen have a super simple control system. both are wired to oil pressure to temp to exhaust temp and finally to the fuel valve. diagnosising problems is very much simplified. no electronics or circuit boards. model t maybe but easy definetly.
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Old 11-27-2019, 09:09 AM   #73
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Originally Posted by mvweebles View Post
Idea of installing a separate water pump is new for me, and seems bizarre. I'm in the process of installing a northern lights 6kw so would like to hear more.

How is ane electric pump that turns on when engine is on better than an engine mounted impellor pump that turns on when the engine is turning? Engine mounted raw water pumps seem pretty reliable, no? What am I missing?
I've encountered the 120 VAC genset raw water pump modification scenario a few times.
On the face of it it's compelling. However, it isn't necessarily as simple as it sounds. First, in response to an earlier post about water leaking into crankcases, most raw water pumps that are gear driven, are separated from the crankcase by an extension, which has a weep hole, it will weep water of the pump seal leaks and oil of the gear seal leaks, so no risk of water entering the crankcase from a leaking seal, making the electric pump unnecessary as a solution to this problem.

You can't simply select any pump for this task, the genset manufacturer selects the impeller pump based on its flow rate, that is critical to balance cooling with back pressure, too much water and back pressure increases, to little water and the system runs to hot.

When mixing seawater and AC current, in a custom installation of this sort, the power supply should be GFCI -protected. None I've encountered had this.

If the pump is wired directly to the genset output, using over-current protection hopefully, it means the genset starts and stops with this load present, albeit small it isn't ideal, and it means the pump itself is subject to rising and plummeting voltage with each start and stop, which isn't ideal for the pump.

The one advantage is many AC raw water pumps are extremely reliable and long-lived, whereas impellers, cams and cover plates of conventional gear or belt driven pumps do require service more frequently.
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Old 11-27-2019, 09:55 AM   #74
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a common mod...get rid of on engine raw water cooling because of expense and dangers/issues of salt water around a genset by using a 110 water pump hooked to the genset to start pumping when 110 is activaed. Usually an air conditioning pump is the replacement.
You're right, external pumps are a swap out to consider. Not sure if any money is saved though. My replacement on engine pump and spare were about $400 each.

On most gensets the raw water pump is at the front of the engine. A leaky pump (we've had one) can easily be spotted and replaced. Little chance of this failure area getting the generator end wet unless you're not checking things.

On the other hand, the exhaust hoses and elbows are commonly right on top of the generator. This area is the trouble spot and remains so even with an external pump. NLs are prone to elbow failures. Which is why the SS version is much preferred. On our Westerbeke the elbow is Al. Surprisingly the Al holds up well. I replace every few years anyway and the old ones come out in great shape.

The worst non elbow/hose genset failures I'm aware of due to water are related to the cockpit mounted units and deck/hatch leaks.
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Old 11-27-2019, 10:13 AM   #75
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There are hundreds or thousands of engine setups, enclosures, types of leaks and how they can affect the generator end by throwing spray inside the enclosure and the generator end fan circulating it.... jusy no telling.


My replacement OEM pump was nearly $700 with shipping.


So the mod works for some really well...not so much for others.
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Old 11-27-2019, 11:47 AM   #76
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a common mod...get rid of on engine raw water cooling because of expense and dangers/issues of salt water around a genset by using a 110 water pump hooked to the genset to start pumping when 110 is activaed. Usually an air conditioning pump is the replacement.
This made no sense to me whatsoever. Given the number of accolades this was getting, I pinged a friend who consults to one of the major marine propulsion manufacturers (including generators). Granted, he's talking propulsion engines, but I don't see a huge difference on all counts except the first comment on pump continuing to run after engine shut down (even then, you'd have to ensure the pump isn't energized by the inverter). BTW - replacement OEM pump for my Northern Lights 6kw is $220.

I'm sorry, to me, this just looks like a solution in search of a problem.

Here's his response:
I have substituted an electric pump for an impeller pump on a propulsion engine twice in an emergency but it is a very easy way to fill an engine with seawater if the flow doesn’t stop immediately when the engine shuts down. It is also very difficult to get anything resembling a good flow match for the cooling system, since the flow isn’t linear with engine RPM, like an impeller pump. At higher loads, when exhaust back pressure is higher, the flow of a centrifugal pump drops dramatically, just when you need the most cooling. So, yes, it sort of works in a limited way but also comes with some seriously engine life threatening caveats.
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Old 11-27-2019, 12:13 PM   #77
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This made no sense to me whatsoever. Given the number of accolades this was getting, I pinged a friend who consults to one of the major marine propulsion manufacturers (including generators). Granted, he's talking propulsion engines, but I don't see a huge difference on all counts except the first comment on pump continuing to run after engine shut down (even then, you'd have to ensure the pump isn't energized by the inverter). BTW - replacement OEM pump for my Northern Lights 6kw is $220.

I'm sorry, to me, this just looks like a solution in search of a problem.

Here's his response:
I have substituted an electric pump for an impeller pump on a propulsion engine twice in an emergency but it is a very easy way to fill an engine with seawater if the flow doesn’t stop immediately when the engine shuts down. It is also very difficult to get anything resembling a good flow match for the cooling system, since the flow isn’t linear with engine RPM, like an impeller pump. At higher loads, when exhaust back pressure is higher, the flow of a centrifugal pump drops dramatically, just when you need the most cooling. So, yes, it sort of works in a limited way but also comes with some seriously engine life threatening caveats.

As I said..it's not a solution for everyone.


It IS for some and they pursued it and are happy with it....with documented, long term positive comments.


Some people change their impeller every year on their genset and it is a royal pain to get to.


Once this mod is done you could go many years without a single issue


So just because someone don't see an issue or need to change, doesn't mean it's not a good idea or practical in some cases. I have thought about it, but didn't as only pump cost was my issue so far.


The problems that have been pointed out about electric conversions are easily overcome as well on some genset units and installs. Probably less so on main propulsion engines.
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Old 11-27-2019, 01:03 PM   #78
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[QUOTE=mvweebles;824057] Here's his response:
It is also very difficult to get anything resembling a good flow match for the cooling system, since the flow isn’t linear with engine RPM, like an impeller pump. /QUOTE]

MV

We are debating a constant speed genset modification pump. At constant speed the pump sizing + a cushion can be selected quite accurately, very different than a highly variable RPM propulsion engine. Not intending to say an external pump is better or not, just saying the point you've referenced does not apply.

BTW, I've worked with multi thousand Kw diesel genset applications that used electrically driven external pumps. Pump maintenance could be done offline with a spare cooling pump setup. The pumps had their own maintenance schedule and life span as compared to the diesel.
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Old 11-27-2019, 01:17 PM   #79
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At constant speed the pump sizing + a cushion can be selected quite accurately, very different than a highly variable RPM propulsion engine. Not intending to say an external pump is better or not, just saying the point you've referenced does not apply.
Point taken, and understood.

Can folks please point out which marine generators in the 6kw-12kw range they believe are improved with the use of an external pump? I just want to know which ones haven't solved one of the very basic requirements of an engine - cooling (or ease of service). And that their engineering is so poor that their mechanical self-priming pump run off a diesel engine is less reliable than a non-self-priming pump run off a separate electric motor (which is run off the generator).

Are you guys punking me? Are we talking decent generators here? Onan? Northern Lights? Westerbeke? Kohler? Made in the last 20 or so years?
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Old 11-27-2019, 02:02 PM   #80
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Can folks please point out which marine generators in the 6kw-12kw range they believe are improved with the use of an external pump? ? Northern Lights? Westerbeke? Kohler? Made in the last 20 or so years?
Not me. Remembering though this is the internet where uncommon things can be bandied around.
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