PassageMaker - April 2009

LETTERS TO THE EDITOR

the closed position. The same problem often afflicts the float switch within the sump box. Unless you intend to clean the check valve (and switch) regularly, this device may by more trouble than it’s worth.

The solution for short cycling is either to reroute the hose so water does not flow back into the sump box or to wire the pump to a manual switch in the head that’s simply turned on by the user whenever the shower is used. (Remember to include a pilot light so that the switch isn’t inadvertently left on.) With this approach, check valves and float switches—the two most common points of failure in a shower sump—become unnecessary. Opening and cleaning the sump and pump periodically will improve the system’s reliability.—Steve D’Antonio

MORE ON HULL STRAINERS

I have a Grand Banks 42 with a 375hp Caterpillar 3208 engine and was using a slotted-type strainer. In Nantucket, for two consecutive summers, one of the strainers clogged with eelgrass and shut down the engine. As you probably know, there is lots of eelgrass floating around in New England. I switched to the Groco APHS-1250-1 perforated-type strainer, and I have not had any trouble since. According to Groco, the smallest holes allow the most water through, but as you point out, you have to be careful when painting over the holes.

I am switching to a newer GB with a Cummins 450hp engine and am wondering if that same strainer will be too restrictive. I think the APHS-1250 is the biggest one that Groco makes. In your response to Ben Doliber’s

letter in the February issue of PMM, you mentioned that engine manufacturers specify maximum inlet restrictions. Where can I find this information? Would it be listed on the Cummins website?

Thanks for your thoughts.

Rockwell Lowe Williamsburg, Virginia

Your question is a valid one, indeed, and I concede that there are locations where a perforated strainer, rather than a slotted one, makes sense.

Restriction can be an issue. Check out the Groco website to make certain the overall collective opening of the perforated strainer equals the size of the engine intake (see groco.net/08- CD-BURN/GROCO%20CAT/CAT- BRWSR/ sec-5-view.htm). After everything has been installed,

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