29
Flush Cycle Adjustment
Before shipping from the factory the Newport watermaker flush cycle is set to factory default
settings. After initial start up, and annually thereafter, the flush cycle parameters must be ad-
justed to ensure that the salt water is thoroughly flushed out of the machine while at the same
time using the least amount of fresh water possible.
First adjust the flush water pressure regulator
. Remove the 1/2 inch vinyl flush water hose
where it attaches to the flush water inlet fitting at the feed pump module. Push the Auto store
button. Water will begin to flow out of the flush water tube. Using a graduated container, al-
low the water to flow into the container for exactly thirty seconds, then push the stop button. If
more than 3 quarts (3 liters) of water went into the bucket the pressure regulator is set too high,
if less the 2 quarts flow into the bucket the pressure is too low. Adjust the regulator by loosen-
ing the lock nut and turning the adjusting screw. Test again until the correct flow is achieved.
Reconnect the Flush water tube.
Next adjust the feed pump flush speed
. Mounted under the top of the Feed Pump Module,
under the MPC box, is a pump speed controller. On the board are two magnetic switches for
adjusting the pump motor rpm. The switches are narrow silver colored bars about 1/2” (1.5cm)
long. The Increase Speed switch is labeled S2 and is located near the upper right corner of the
board. The Decrease Speed switch is labeled S3 and is located to the right of the six cylindrical
capacitors. Each time a small magnet is placed near the switch while the pump is running, a
signal will be sent to the controller, changing the speed setting, and the pump will speed up or
slow down slightly.
Adjust the flush speed as follows. Push the Auto Store button. Push the Alarm display
button until the display reads PREFILTER GOOD REPLACE. The flush valve will open and
water will flow backwards through the filters and strainers. After about 30 seconds the back-
flush will end and the feed pump will come on, starting the forward flush of the Clark Pump
and membrane. After the feed pump starts, close the service valve, (handle crossways). If the
bar graph on the display begins to move toward REPLACE on the gauge the feed pump is try-
ing to pump more water than the Flush module can supply, and should be slowed down. Turn
the service valve to Service. Water should flow very slowly out of the service hose fitting. If
flow is more than a trickle, speed up the pump. Optimum flush speed will be the speed at
which slightly more water is coming from the flush module than the feed pump is pumping.
This setting will ensure that no sea water is drawn in during the flush, but fresh water is not be-
ing wasted overboard. Check the flush speed by
Adjust the Pump Off time and Pump On time.
The flush begins and ends with the Pump
off. Pump off time should be set so that the feed pump comes on just as fresh water reaches the
sea cock. Pump on time should be adjusted so that the pump runs just long enough for Fresh
water to reach the brine overboard fitting, then stops. Pump On and Pump Off times can be ad-
justed from the laptop computer or the display. See the instructions in Section 2. Flush dura-
tion must be set the same as or higher than the total flush time (two pump off times plus one
pump on time).
Pressure regulator
Increase speed
switch
Decrease
Speed
switch
