On 28 Oct 2003 05:31:53 -0800, (Jim Woodward)
wrote (with possible editing):

I'm afraid this is a general problem. The vast bulk of the market is
so price conscious that those of us who would pay more for quality
can't find it.

It's particularly pervasive in the rec.boats market because many
boaters use their boats only ten or twenty days a year, so a product
with a life of 360 days, which would be a disaster in a home, does
fine on most boats.

DC switches are a prime example of this. DC is hard to switch, so
good switches are much more expensive than AC switches. We've
discussed the Rule switch, but their competitor, Jabsco, does the same
sort of thing with their pressure water control switch. It's a
Honeywell MicroSwitch (tm) with a good AC rating, but, IIRC, a 0.5A DC
rating. Guess what -- the pump draws 5 times that, so the switches
fail predictably after a couple hundred days of use. This is a long
time for the typical rec boat, but a nuisance for the live-aboard. A
satisfactory substitute is hard to find.

Since those of us who live-aboard are a very small market, our only
solution is to share experiences and solutions here and elsewhere.
You're probably dreaming to hope that Rule will do a re-design -- they
have their cost of manufacture, their MTBF, their average customer
use, and their warranty life calculated very carefully and their
business model calls for being market leader, not quality.

Jim Woodward
www.mvFintry.com

Jim is right - DC is much harder to switch as you can't use triacs or
other solid state switches. FWIW, what I would do is to have whatever
switch you use, switch a 12 volt relay with contacts of adequate size
for the amperage drawn by the pump, instead of switching the pump
directly. I would use a pluggable relay and mount that up where it
was easily accessible, then keep a spare on hand.

--

Larry
Email to rapp at lmr dot com