Spectra Watermakers NEWPORT 400 Mk II, Installation & Owner'S Manual

Page: 47 / 62

47
FRESH W A TER FL USH
The purpose of the fresh water flush is to replace the sea wa ter in the wat ermaker with fresh
water whenever the system is not operating. The Auto Flu sh Mode changes the fresh water
every five days if the system has been idle that long. The watermaker wil l last lon ger and
operate b ett er if it is a lways kept fi lled w ith fresh water between uses.
Al l Newport 400 Mk II Spectra Watermakers ar e equipped with a fresh water flush module.
Thi s modu le inc ludes a charcoal filter to remove any chlorine in the fresh water tha t mi ght
damage the membrane. The electrically operated solenoid valve opens dur in g the fresh wa-
ter flush allo win g the boats pressuri zed water system to supply water to th e system. The
charcoal filter has a maximu m f low rate of 1.5 gal lons per m inute (6lp m) so the feed pump is
operated at a r educed spe ed to avoid ex ceeding this f low rate.
If the ship’s water system i s unable to provide flu sh water at the r equired flow rate, sea wat er
wi ll be drawn in to make up the difference. This w il l cause the flush water to be bra ckish,
and ineffective in preserving the watermaker. At initia l startup the fresh water flush system
should be tested by taking a samp le of the brine discharge water just as the flush cycle i s
ending. Th is water should not taste salty, and should read less than 1000 ppm on a d i gital
tds meter. The flush cycle can also be tested by closin g the sea cock during the flush cycle.
If the MPC - 5000 display g ives a SER VICE PREFILTER alarm this means that the fresh wa-
ter supply is insuff icient. In this case it is very i mportant to either increase the wat er supply
or adjust the feed pump flush speed as shown in the Sy stem Startup instructions.
Because th e pre - filters trap the plankton in the feed wa ter th ey can b e subject to “going an-
aerobic” or starting to smel l like rotten eg gs, as the trapped plankton de cay. For this reason
it is adv isable to always put in clean elements if the unit is go in g to be left on Auto Flush
Mode. In daily or re gular use the fresh water flush after ea ch shutdown wil l help prevent
this proble m, but in excessive ly warm or ferti le waters the pre - filters wi ll need regu lar atten-
tion.