Spectra Watermaker downgrade?

[Reefmagnet]

I picked up a good used Spectra Newport 400 watermaker for our boat last week. It's more capacity then required but it was an offer too good to refuse. I'm intending to break the unit down into components sans electronics and distribute it's bit's and pieces around the boat and make it an entirely manually operated system. So far so good, but ideally I'd like to reduce it's product output by around half (~ 30 lph) if feasible as I think this would better match our tankage and usage.

I'm seeking opinions on whether it would be possible to either run the existing low pressure pump at reduced speed using speed controller (which I'll be using for fresh water flushing anyhow), or to replace the pump altogether with a smaller shurflo unit?

Thanks!

[donradcliffe]

The best way to downgrade it is to run it half the time.

[Reefmagnet]

Originally Posted by donradcliffe

The best way to downgrade it is to run it half the time.

Thanks for that opinion, however I'm interested specifically in the two options mentioned.

[travellerw]

Tellie is the man..

I'm guessing the answer will be to only have 1 membrane instead of 2.

Although 1/2 time running would work too...

[belizesailor]

I dont know any water maker owners who wish they had gone smaller. Most wish they had gone bigger, including me. You can as suggested always just run it less, but still have more capacity when needed.

[model 10]

I think Tellie or Rich should get off the bar stool and set you on a straight course. For example, how would using a smaller low pressure pump work?

[Reefmagnet]

Yeah no big deal if downgrading not possible. I just feel that running a watermaker for relatively short periods at intervals of a few days predominantly in the tropics might be cutting too close to causing other problems as it's my understanding that watermakers like to be run often which would be a struggle at the rated production. Also, reducing the power requirements of 24Amps (12VDC) would be nice on a smallish vessel such as ours.

[travellerw]

Originally Posted by Reefmagnet

Yeah no big deal if downgrading not possible. I just feel that running a watermaker for relatively short periods at intervals of a few days predominantly in the tropics might be cutting too close to causing other problems as it's my understanding that watermakers like to be run often which would be a struggle at the rated production. Also, reducing the power requirements of 24Amps (12VDC) would be nice on a smallish vessel such as ours.

I will let the experts chime in, but I don't think reducing the output would reduce the draw by 1/2. As long as you are running the maker every 4-5 days, you should be fine.

[model 10]

Live it up a little, flush your toilet with fresh water, take showers, cook pasta with big pots of water. You have the power to run it and good tankage?

[autumnbreeze27]

Setup a fresh water washdown hose so you can hose the salt off your boat.

I wouldn't try and downgrade it. If you won't be running it for more than 3 days, just flush it with fresh water. If less than 3 days you don't do anything.

Make some friends and offer them free water.

[Reefmagnet]

Ok, maybe I was overthinking this? The missus certainly isn't complaining about excess water and an anchor chain / deck wash is appealing. We've got about 200 to 280 watts solar, 360 a/h batteries, a Honda 1k genset and Sterling 50A charger. Tankage is approx 300 litres split over two tanks. We're out of the water re-fitting at the moment but once back in the drink we're off full time cruising.

[Hoghead]

The functions related to output that you can control are flow rate and pressure.
Reduce either or both to achieve your result, keeping in mind that the membrane will have a lower pressure limit

Or use 1 membrane and sell the other to me if it a 4 x 40" !!

You will be surprised on how much water you can use if the supply is unlimited - specially in the tropics where it is nice to shower twice a day

[Tellie]

Originally Posted by Reefmagnet

I picked up a good used Spectra Newport 400 watermaker for our boat last week. It's more capacity then required but it was an offer too good to refuse. I'm intending to break the unit down into components sans electronics and distribute it's bit's and pieces around the boat and make it an entirely manually operated system. So far so good, but ideally I'd like to reduce it's product output by around half (~ 30 lph) if feasible as I think this would better match our tankage and usage.

I'm seeking opinions on whether it would be possible to either run the existing low pressure pump at reduced speed using speed controller (which I'll be using for fresh water flushing anyhow), or to replace the pump altogether with a smaller shurflo unit?

Thanks!

Good on you for finding a used Spectra, they're hard to come by. First thing is it depends on what model and year is the NewPort400? The newer systems have a VFD that allows for high and low speed operation. Is there a problem with the existing electronic controls? All NewPort400s come manual operation capable already. Second, making it a smaller capacity system doesn't really make sense at the outset. The energy savings per gallon made by swapping to a single Shurflo pump are negligible at best and you'd have to more than double the run time on a Shurflo pump to make the amount of water the existing 400 pump can. What I have seen done on the NP400s is where owners have kept the main feed pump module as is to run normally, but add a single Shurflo pump to the side of the module and plumb it into the system. This way if the main pump failed for any reason there is an automatic back up in the Shurflo set up. This would kind of give you what you are looking to do adding a nice redundancy to the system if either or pump failed. You could not run them both at the same time though as you would create too much pressure in the membrane vessel. Send me a few pictures of what you have and I can better determine what makes sense. Also let us know how much water capacity you have and how many gallons of water you use in a day on average. My guess is that you may be over thinking this and you'll want to keep it the way it is. But let me know if I can help in any way.

Halden Marine Services | Marine Watermakers, Solar Panels, Wind Generators

[Tellie]

Originally Posted by Guy

I think Tellie or Rich should get off the bar stool and set you on a straight course. For example, how would using a smaller low pressure pump work?

Rich and I have been busy at the Fort Lauderdale show this past weekend. My guess is he's like me and a bit worn out.

Halden Marine Services | Marine Watermakers, Solar Panels, Wind Generators

[Reefmagnet]

Originally Posted by Tellie

Good on you for finding a used Spectra, they're hard to come by. First thing is it depends on what model and year is the NewPort400? The newer systems have a VFD that allows for high and low speed operation. Is there a problem with the existing electronic controls? All NewPort400s come manual operation capable already. Second, making it a smaller capacity system doesn't really make sense at the outset. The energy savings per gallon made by swapping to a single Shurflo pump are negligible at best and you'd have to more than double the run time on a Shurflo pump to make the amount of water the existing 400 pump can. What I have seen done on the NP400s is where owners have kept the main feed pump module as is to run normally, but add a single Shurflo pump to the side of the module and plumb it into the system. This way if the main pump failed for any reason there is an automatic back up in the Shurflo set up. This would kind of give you what you are looking to do adding a nice redundancy to the system if either or pump failed. You could not run them both at the same time though as you would create too much pressure in the membrane vessel. Send me a few pictures of what you have and I can better determine what makes sense. Also let us know how much water capacity you have and how many gallons of water you use in a day on average. My guess is that you may be over thinking this and you'll want to keep it the way it is. But let me know if I can help in any way.

Halden Marine Services | Marine Watermakers, Solar Panels, Wind Generators

Thanks Tellie


Here's some pics




Looks like it was made around the end of '02 and is reasonably complete except for the MPC3000 (?) Display. I haven't fired it up yet, but everything looks to be in good condition but I've no idea if the electronics (or anything else!) work . I believe it's been out of service for quite sometime so I'll be looking to go over it with a fine tooth comb.

We have about 300 litres tank capacity and use about 30 to 40 litres a day with just the two of us. As for reducing the capacity, aside from the issues of maximum current draw and runtimes, I was also thinking that if the pump head turns out to be worn out, I could simply replace the drive with the appropriate ShurFlo pump. Then I did a bit of reading and found that clark pumps come in some slightly different configurations which left me a bit confused as to whether they need to be matched to the pump and/or membrane combination. Having said all that, if you reckon that the system would work as is, I'm happy with that!