T&T: Cruisair P1500BXT Raw Water Pump Question

[Pauline and Rod]

Our boat's airconditioning system uses a TaylorMade/Cruisair raw water pump
1320gph, with a Dayton electric motor. The unit model number appears to be
P1500BXT, perhaps the pump model number is Tx 12060401/04.
Our pump is leaking, apparently from it's mechanical seal. A complete
replacement unit will cost around $800. Therefore it seems sensible to look
at an overhaul, either a pump only replacement or a pump overhaul including
a new mechanical seal.
It appears pump parts are available, Pump Head Assembly Cruisair 1031000
for around $600, and seal kit A505 $100 or 725115000 $100.
However we've not been able to find a parts listing showing the
configuration inside the pump. Perhaps it's not really practical to
overhaul the unit at all because perhaps it's not practical to remove the
pump impeller from the electric motor shaft because it may be corroded in
place. Has anyone attempted a repair on one of these units please? Is
anyone able to help us figure if an overhaul is practical, and if so where
best to get a parts breakup showing the assembly arrangement,
assembly/disassembly instructions, and where best we can buy the parts?
Thanks from Rod and Pauline
"Two by Two" Nova Scotia 47 Pilothouse Trawler
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[Frank Burrows]

Rod:

I did a google search for the model number and cam up with this thread:

http://www.samsmarine.com/forums/showthread.php?20294-Cruise-Air-Seawater-pump

Depco is probably the best source of information and the best prices

http://www.depcopump.com/

Frank Burrows

On 12/1/2012 8:42 AM, Pauline and Rod wrote:
> Our boat's airconditioning system uses a TaylorMade/Cruisair raw water pump
> 1320gph, with a Dayton electric motor. The unit model number appears to be
> P1500BXT,

[Jim Healy]

Rod and Pauline,

There are any number of pumps out there that circulate raw water for marine heat pump and refrigeration systems. As in almost any mature industry, they are almost commodities. If you're an MTOA member, call Woody Sherrod in Annapolis and ask him for his thoughts. He's and great guy, and he's "in the business."

At $800, I ass/u/me you'd be paying an ***enormous*** premium for the CruisAir name. For example, a couple of years ago, a friend of mine had the air blower motor fail on his CruisAir. It's a little universal motor mounted on a unique, integrated, proprietary sheet metal mounting bracket. CruisAir wanted $400 and change for a replacement motor/bracket ass'y. Instead, we took it to a local motor rewinder, had it refurbed, and put it back in service for less than $60. It's been running fine for 4 years now.

If you really want the existing CruisAir pump, as others have said, have it refurbed by Depco in Clearwater, FL. They are by far the best-of-breed on anything to do with pumps of any kind, and they are also superb people with whom to deal.

One thing you said which bothered me is that the pump seal appears to be "leaking." I ass/u/me you meant leaking shaft seal, so my comments, following, apply to that design. On boats, raw water cooling pumps should be designed in a way that there is no shaft providing mechanical drive to the impeller, therefore, no shaft seal to leak. The water gallery where the impeller lives should not have any perforations except the water inlet and outlet ports. They should be made of plastic or composition material to resist corrosion and the motive drive should be by induction, with rare earth magnets. The motor should have ball bearings, not sleeve bearings, so it can be mounted vertically with the pump (wet) end down. The shaft spins a magnet. The impeller is magnetic. When the driven magnet spins, the impeller spins by magnetic, not mechanical, coupling. NO WATER should be able to leak out of the actual water gallery of the pump. Having said is should not leak, mounted vertically with the wet end down makes sure noting ever leaks into the motor itself.

One thing that will cause a pump to make funny noises is if air gets into it. Raw water circulator pumps are not self-priming, and should be located below the water line. Mine will lose prime in rough seas. If that happens, the symptom is that the pump will "run dry," and the impeller with vibrate on it's ceramic axle and make a hellacious racket. Just bleed the air (I installed a burping valve to facilitate that) and the problem is instantly solved.

Finally, be very careful of el-cheepo pumps from places like Grainger. Yes, some of their pumps *are* meant for raw water applications, but not all, and certainly not the low-price models. Pumps that are made for pumping semi-corrosives will have stainless steel internal components. The impeller rides on a ceramic axle, and the impeller itself in non-metallic and magnetically, not mechanically driven, so there should be no drive shaft and seals penetrating the water gallery. Most Grainer pumps do not meet these specifications, and if you go that way, you are buying a repeat failure in the future. And in case you're thinking you'll sell the boat before that happens, it is something a competent surveyor should find! So one way or the other, that cheap pump will cost ya in the end.

Some retail pumps, like Grundfos, are pretty good mid-price compromise for semi-corrosives; and their higher price-point reflects that. Not so much Tyco; they are throw-aways made for fresh water applications, like hydronic hot water baseboard heat circulators. I happen to like - and recommend - Little Giant Pumps. Not exorbitantly expensive, and built for purpose. The Little Giant Pumps that are made for salt water are in their "semi-corrosives" product group; salt water is a semi-corrosive acid, which is why simple steel parts are ng for the application.

NO PERSONAL INTEREST IN ANY PERSONAL REFERENCE, PRODUCT BRAND OR LABEL. Just a old boater...

Hope this is useful.

Jim

Peg and Jim Healy aboard Sanctuary
Currently southbound at St. Lucie Lock, Stuart, FL
Monk 36 Hull #132
MMSI #367042570
AGLCA #3767
MTOA #3436

[Richard Tomkinson]

I happen to like - and recommend - Little Giant Pumps. Not exorbitantly
expensive, and built for purpose. The Little Giant Pumps that are made for
salt water are in their "semi-corrosives" product group; salt water is a
semi-corrosive acid, which is why simple steel parts are ng for the
application.

Anybody replace their engine powered raw water pump with an electric one
such as described above?

I can think of a number of reasons to do this:
1. in winter in the PNW, one could easily run a heat pump using the same
pump as engine cooling (engine off, boat unattended).
2. For boats with a shaft tube and therefore a risk of crevice corrosion,
running the pump on a timer would put 'fresh' raw water through the shaft
tube without starting the engine.

Is it reasonable to use such a pump as a primary raw water cooling pump?

Seems to beat the risk of failure inherent in the Lehman 120 pump.
Richard

[Rich Gano]

Where do you get data supporting "the risk of failure inherent in the Lehman
120 pump"?

I personally have had a couple of shaft seals go out, with plenty of
slow-drip warning time, on my two L120s, and I have found an impeller blade
or two cracked at inspection time. Are these "failures?"

I have never had an engine overheat due to any of these four or five
"issues," and they stretch back to 1986.

I have a couple of Little Giant centrifugal sump pumps under my house, and
they are wonderful. However, I would hesitate to change the gear-driven
pumps on my L120s to electrical pumps for reasons like I don't know the
varying water flow demands of the engine at differing RPM settings. Could a
fault make for failure of the pump to shut off with engine shutdown thus
flooding the engine's cylinders?

The Johnson rubber impeller pumps I changed to years ago seem to be free of
some of the defects of the original ITT pumps. I wonder if an improved pump
design for pumps like many of ours which are always below the waterline
could include a gear or belt-driven centrifugal pump (possibly with magnetic
drive to avoid the shaft-seal issue) so we could have the best of all
worlds?

Rich Gano
Calypso (GB42 Hull # 295)
Panama City area, FL

-----Original Message-----
Richard Tomkinson
Sent: Monday, December 03, 2012 8:45 PM
Cc: traw...@lists.trawlering.com
Subject: Re: T&T: Cruisair P1500BXT Raw Water Pump Question

[Richard Tomkinson]

> Where do you get data supporting "the risk of failure inherent in the
> Lehman
> 120 pump"?

Same source as you, experience.

From what you report, even with the Johnson pumps you have has issues,
albeit none risking the engine. Ask what other issue on the engines has
caused four specific maintenance concerns. One also wonders why the change
to Johnson pumps if the originals did not cause problems.

My experience with a single is that over 25 years, the pump is second only
to periodic hose leaks as maintenance concerns (ignoring oil changes). I
have had one unexpected engine overheat to shutdown, that was caused by the
pump connection (a known weakness) failure from a plastic bag over the inlet
in a harbor at near zero speed. I rebuild my pump every three years then
after another three years get a new one.

I am intrigued by the possibility of an electric powered pump both for multi
use and to improve reliability.

[Ted or Sally]

We have an electric mag drive pump on our Westerbeke 12.5 generator. When
the gen starts, it energizes the pump, which supplies raw water for
cooling. It's worked great for 9 years.

Ted G
DeFever 44, Amici
Currently Legacy Harbour

On Wed, Dec 5, 2012 at 3:14 PM, Richard Tomkinson <capn...@wavecable.com>wrote:

>
>
> SNIP:

[Rich Gano]

You misunderstood. No problems with the Johnsons, but they have only been
in there since 2004. Originals had all the problems.

Plastic bags and the sort are always a threat to those of us with raw water
intakes for engine cooling. You might want to consider copying something I
added to avoid the deadly overheat condition. Place a 160-degree F button
switch on the wet exhaust opposite the raw water injection hole. Hook that
to an alarm bell, and almost the instant you lose cooling flow, the bell
goes of - well before the engine's internal coolant can get hot enough to
set off the heat switch immersed in the coolant.

The place in the PNW which made the "Norm switches" I use on all three
engines in the boat is no longer in business, but I am sure the ingenious
sort can figure out how to strap one on and provide power to a solid
latching circuit with manual alarm shut-off. Happy to provide diagram.

Rich Gano

-----Original Message-----

> Where do you get data supporting "the risk of failure inherent in the
> Lehman
> 120 pump"?

Same source as you, experience.

From what you report, even with the Johnson pumps you have has issues,
albeit none risking the engine. Ask what other issue on the engines has
caused four specific maintenance concerns. One also wonders why the change
to Johnson pumps if the originals did not cause problems.

[Rich Gano]

How did you determine the flow requirement?

Rich Gano

[Steve Sipe]

On 12/5/2012 3:36 PM, Ted or Sally wrote:
> We have an electric mag drive pump on our Westerbeke 12.5 generator. When
> the gen starts, it energizes the pump, which supplies raw water for
> cooling. It's worked great for 9 years.
>

I also installed a similar setup on my own 12.5 Westerbeke after
replacing impellers, seals, etc. at short service intervals. The
electric pump is from Depco, a "Primetime" model. It's worked like a
charm with one caveat. - I had a failure of the capacitor after about a
year. Not a big deal, but I was concerned that there may be an
underlying problem that I was missing. After some investigation, I
attributed the failure to the fact that the pump is starting before the
genset has reached full voltage, and my experience has been that voltage
sags are hard on capacitors.

In order to keep the pump from starting until the genset has come up to
full rpm, I wired the pump into a 12v relay that is wired in parallel to
the "hold-in" relay on the genset start circuit. It's relatively simple
to do, the relay is commonly available, and it's worked well. The pump
now has full voltage when it starts, and I've not had further capacitor
problems. That being said, the capacitor could have spontaneously
failed, but I generally don't subscribe to the spontaneous failure
school of thought. There's usually a reason.<G> I figure at least I've
improved the chances against a repeat failure.

Bottom line is, I wouldn't hesitate recommending an electric pump as a
replacement for a troublesome impeller pump.

--
Steve Sipe
Solo 4303 "Maerin"
Middle River, MD

[L H]

Does this pump run on 12v DC or 120v AC?

Larry H

On 12/5/12 3:38 PM, Steve Sipe wrote:
> On 12/5/2012 3:36 PM, Ted or Sally wrote:
>> We have an electric mag drive pump on our Westerbeke 12.5 generator.
>> When
>> the gen starts, it energizes the pump, which supplies raw water for
>> cooling. It's worked great for 9 years.
>>
> I also installed a similar setup on my own 12.5 Westerbeke after
> replacing impellers, seals, etc. at short service intervals. The
> electric pump is from Depco, a "Primetime" model.
>

[Steve Sipe]

On 12/5/2012 8:43 PM, L H wrote:
> Does this pump run on 12v DC or 120v AC?

I believe it can be configured either way, as well as hydraulic.

--
Steve Sipe
Solo 4303 "Maerin"
Middle River, MD

[Richard Tomkinson]

Place a 160-degree F button
> switch on the wet exhaust opposite the raw water injection hole. Hook
> that
> to an alarm bell, and almost the instant you lose cooling flow, the bell
> goes of - well before the engine's internal coolant can get hot enough to
> set off the heat switch immersed in the coolant.

I use a 120 degree sensor to power the raw water flow alarm, it worked so no
problems with overheating (we coasted to the dock).

Still interested in alternatives to the mechanical pump.