Re: Watermaker Dead


amelliahona <no_reply@...>
 

Hi Ed. Thanks for the confirmations on the relay voltages.

--- In amelyachtowners@yahoogroups.com, "edmund_steele" <edmundsteele@...> wrote:

" .....I could disconnect the Plug #1 (it does pull off, doesn't it?)"

Yes, the plugs do come off the Logic Board.

Ed wrote: "... by applying 24 volts of either polarity to the
Violet, green and orange pairs, override the control board. It is my
understanding that if you put 24V power on the HP (violet) and the
Bypass Solenoid Control (orange) about two minutes after applying 24V
power to the BP (green), then you will have duplicated what the
control panel does. Is this correct?"

That is basically correct. While polarity probably should not be an issue,
for the relays, in order to duplicate what is there the + (Positive)
polarity for the 24 VDC is on PLUG 1: Pin 6 (Violet for the Hi Pressure
Pump), Pin 8 (Green for the Low Pressure Pump), and Pin 10 (Orange
for the Bypass Solenoid), YOU WILL ALSO NEED TO PROVIDE A
GROUND RETURN BY JUMPERING PINS 7, 9, 11 & 1. Timing is
another issue. I believe that 60 seconds after the low pressure
pump starts, the Hi Pressure pump starts, and 60 seconds after
that the Bypass Solenoid Energizes.

Ed wrote: "On the control board, the only fuse with power to it is
the F1 which showed 24V. The other three showed continuity but
no power."

That is interesting. There should be 220 VAC between Pins 4 (220
VAC input) and Pin 1 (Ground). I believe that you previously
mentioned that the green LED on the board was illuminated as
well as the Red Control Panel LED. That idicates that 5 VDC power
is available on the Logic Board.

The 5 VDC comes from the 220 VAC. 220 VAC (supplied on pin
4 of Plug 1, with ground on Pin 1 of Plug 1) is rectified to DC by
Rect. & C1 to 63 VDC (see Photos Section Dessalator Watermaker
Service - Board Part Number photo), then regulated to 12 VDC by
T1 and 5 VDC by T2. The 5 VDC is used for all of the logic ICs
and also is what illuminates the Green Logic Board LED as well as
all the three LEDs on the Control Panel. If those LEDS are lit then
220 VAC is making it to the board.

As best as I can tell, the only real logic that works on the board,
other than the timers, is the high pressure switch logic. On the
back of the High Pressure Gauge/High Pressure Restrictor Valve
Manifold (rear of control panel lower left hand corner) is a
pressure switch which is NO (Normally Open) I believe. This is
set to close at a pre-determined pressure (Dessalator told me
what it was once but I don't recall now) in order to protect all
the plumbing from excessively high pressures. When it closes
it triggers a logic low that will unlatch one of the ICs and shut
the system down, triggering the Red Panel LED at the same time.

It is possible that this sensor has failed in the Closed position
and is causing your problem. You might check the continuity
of it by disconnecting Plug 2 and measuring across Pins 8 & 9.

Good luck and let me know what you find.

Gary

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