|
|
|
|
|||||
|
||||||
Subject: TWL: Electrical Problem
From: Nunas (Nunas@XXX.XXX)
Date: Fri Feb 01 2002 - 19:01:02 EST
Here's one to chew on. We bought these way-cool electric lights for the
boat. They have no switch, just two "touch pads"; one pad is a dimmer
(touch and the lamp dims, release and touch again and it gets brighter)
and the other is the "mode" switch. The modes are on, on-with-motion,
on-with-darkness, random-on/off, and off. These are so useful on the
boat. When we leave the boat, we set one lamp to come on at dark. We
have two others set so that when we walk into the room in the dark, they
go on. They go off a few minutes after we leave. If we go away for
more than a day, we can set one or two to random mode. Now for the
strange thing...
These lights normally work just fine on shore power. They won't work on
generator power or on the inverter. Using these two power sources, the
lamps come on "on-with-darkness" mode when power is applied, and the
dimmer and mode switches don't function. You have to wait until
daylight or pull the plug to turn off the little buggers. It's most
frustrating.
We first assumed that the problem was a difference in voltage--- nope,
about the same for all three sources. Also, the lamps do function in a
limited way; that is, they come on and off with daylight...so the
circuit inside is actually working. Then we thought that it was the
wave shape--could be...no way to test.
We are now on the hard and the lamps were working fine on shore power.
Then one day they started to act as if the shore power had tripped and
the inverter had taken over (it happens a lot on the hard). But, that
was not the case. What could have changed?
Today we got a new clue! The fibreglass man was down in the bilge
working with his electric grinder; when his arm touched the generator
sound shield he got a shock. We looked at the shore power connection
and the safety ground had come off. We hooked it back up and he
continued working...then we realized that the damned lamps were again
working. We took off the safety ground and they reverted to their
faulty state.
It gets stranger. These lamps do not have a three-wire cord; they have
only a 2-wire cord (the hot and the neutral).
Our current theory is that since the controls work on body capacitance
(the plates are covered with plastic) they need to see that capacitance
against something. That something is the safety ground. Neither the
generator nor the inverter uses the safety ground. So why this long
email? How on earth can we get these things to work when the boat is on
the hook? Have at it trouble-shooters!
Best,
Maurice & Louise-Ann
AKAMA, KK48 Whaleback #2
Raffles Marina, Singapore
|