Electric genset raw water alternative to march

[a64pilot]

Originally Posted by kenbo

Hey 64pilot, I always wanted to ask you about your genset water pump">raw water pump. I think it's a great idea but there is a failure mode that worries me. What happens if the generator end fails, there's no AC to power the pump but the engine is still running. Is there a system to shut down the engine before it overheats?

I’m sure truth be known that it wasn’t my idea, I’m certain I heard it here, but don’t know from who.
However the failure mode of an electric pump failing is the same as a mechanical one, that is the gen will overheat and shutdown from the Murphy switch. Seeing as how the mechanical one fails often and I replaced it with an electric one, I think the likelihood of a failure is less.
I replaced mine cause the mechanical one developed a leak and began spraying salt water all over inside of the enclosure without me knowing, and the generator is an air cooled thing and of course was ingesting salt water. Only way I found out was the pump eventually seized, throwing off the belt and the gen overheated and shut down.
Exhaust system seemed unharmed.

I didn’t want that to ever happen again, so what I was really doing was removing the pump from inside of the enclosure to prevent any further salt water baths.
There are of course overheat and no water flow alarms, some are not all that expensive if you think it necessary.
However I never run the generator without being on board, and as I run it to power “things” power goes off and even if I don’t notice the exhaust suddenly getting louder, I’ll probably notice the “things” are no longer working and check to see what is going on.

[svHyLyte]

Originally Posted by Sailmonkey

The brown plastic is not a shroud, the motor is encapsulated and water cooled. No motor maintenance is possible. However the pump is submersible.

Ah hah... Learn something new every day. My assumption was based upon a friend's boat who has a plastic cover over his drive motor and I assumed A-64's was the same. Assumption is the root of error too often, eh?

[svHyLyte]

Originally Posted by svHyLyte

Ah hah... Learn something new every day. My assumption was based upon a friend's boat who has a plastic cover over his drive motor and I assumed A-64's was the same. Assumption is the root of error too often, eh?

Further to the foregoing, yesterday I ran into our slip neighbor with the plastic cover and mentioned this discussion. He explained that the shroud over his March pump is actually a cover for a Jabsco electric head conversion kit. It seems that at some point he had to purchase a replacement conversion kit and so ended up with two covers. Accordingly, he cleaned and painted one "teak brown" (kind'a) and secured it over his March pump which is installed under his galley sink counter to protect the pump drive motor from water drips. When showing him how to lubricate his drive motor, I simply "assumed" (that dreaded word again) that the shroud he removed for access was part of the original equipment for the pump which it was not. So, still learning something new every day.

FWIW...

[CaptTom]

That green pump in the first post looks identical to one I picked up on eBay, intending to save money over a March air conditioner pump. The thing rusted pretty badly. The March pumps are mostly non-metallic, magnetic drive, and are made to live in bilges.

I assume any brand pump made for use in marine air conditioning would work, it doesn't have to be March. What do they usually use down there?

[a64pilot]

There are of course several March pumps, of different designs.
It’s sort of Akin to saying Chevrolet Automobile, that covers a pretty wide variety.

I only used a March pump to maintain commonality with my air conditioners, so that way I carry one spare that can be used every applications as opposed to having to buy and carry multiples.
I’m certain that any continuous duty cycle electric pump would work if it’s the right flow rate.

[a64pilot]

My forward AC pump is this guy, it came with the AC as part of the kit.
I didn’t think it would last long but installed it anyway as it came in the kit.
Three years later and it’s still going strong. I think it would also work on a small generator. When it goes I’ll put the March in.


Available here and other places for about $90. https://www.bulkreefsupply.com/pan-w...hoCnsQQAvD_BwE
I have seen it’s 12V brother on EBay for $65 or so

[a64pilot]

You know, when I start looking at 500 GPH aquarium pump, I come up with a lot of March looking pumps, at less than 1/3 the cost, anybody know why a salt water submersible aquarium pump won’t work? They are continuous duty, running 24/7.
https://www.saltwateraquarium.com/ma...hoCl14QAvD_BwE

[svHyLyte]

Originally Posted by a64pilot

You know, when I start looking at 500 GPH aquarium pump, I come up with a lot of March looking pumps, at less than 1/3 the cost, anybody know why a salt water submersible aquarium pump won’t work? They are continuous duty, running 24/7.
https://www.saltwateraquarium.com/ma...hoCl14QAvD_BwE

Submersible pump motors are sealed and so rely upon submersion for cooling. Absent that, the bearings tend to burn up fairly quickly.

[a64pilot]

I took it that they could be submersed, but it’s not required.
The most commonly used March pump, the one that has the motor encased in some form of reddish plastic is submersible, but I think rarely is.
I get your point though, ensure pump is allowed but is not required to be submerged for cooling.
Only ones I am aware of that require submersion have no inlet hose fitting, they are like bilge pumps, have the screen as part of the pump body.
I priced a March myself, and they are very spendy, I had forgotten how much so I’m interested in an alternative, and maybe a non Marine item could be the ticket, like a BIG salt water aquarium pump, they are designed and intended to run 24/7 for a long time, years.

[a64pilot]

One I linked to says operates submerged or inline in its product description.

[Sailmonkey]

Originally Posted by a64pilot

One I linked to says operates submerged or inline in its product description.

I’ve been using an Iwaki pump on the AC for 5 years. Ow without a problem.

https://www.iwakiamerica.com/products/wmd.htm