Mars Air Systems L-2254 - Manual (Page 15)

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English L-2254 Maintenance
MAINTENANCE
Reversing Valves
Reverse cycle units have a reversing valve; the valve
must be energized periodically to keep the internal parts
moving freely. To do this, switch the a/c unit into heat for
a few seconds once a month.
Seawater Strainer
Insure that your pump receives adequate seawater flow
by regularly cleaning the strainer basket. Periodically
check the overboard discharge for a steady stream of
water. Check seawater intake speed scoop for obstruc-
tions. Make sure hoses are not looped, kinked or
crushed.
Condenser Coil Cleaning
1. With the system turned off at the circuit breaker on the
ship’s panel, disconnect the inlet and outlet connec-
tions of the condenser coil.
2. Use chemical resistant hoses (MAS white PVC 5/8”
I.D., etc.) to connect the inlet of the condenser coil to
the outlet of a chemical resistant, submersible pump
(MAS P-500 pump, etc.) and let the hose connected to
the coil outlet flow freely into the container mentioned
below.
3. Place a strainer or piece of screen over the inlet of the
pump and submerse the pump into a container filled
with a 5% solution of muriatic or hydrochloric acid and
fresh water or use a premixed over-the-counter
solution. Use a large container as possible to hold the
solution (5-25 gallons).
CAUTION: Avoid spilling or splashing the solution.
Follow all warnings and recommendations given by the
manufacturer of any acids or premixed solutions.
4. Power the pump and circulate the solution through the
condenser coil for 15-45 minutes depending upon the
size of the coils and the extent of the contamination.
Visual inspection of the solution in the container
should indicate when the contamination removal has
stopped.
5. Circulate fresh water through the coil to flush any
residual acid from the system.
6. Restart the system and check operational parameters
to ensure thorough cleaning has taken place. Addi-
tional cleaning may be necessary with extreme
contamination.
WARNING: For the purpose of protecting the environ-
ment, dispose of any contaminated acid solutions in
accordance with federal, state and/or local regulations.
Return Air Filters
Check the return air filter about once a month and clean
as necessary. To clean the filter, remove it from the unit,
rinse with water, air dry and reinstall.
Winterization
There are several methods of winterization, some of
which work better than others. The four various methods
employed using a 50/50 nonpolluting biodegradable
antifreeze/water solution are:
1. Pumping of antifreeze solution into the overboard thru-
hull fitting, and discharging through the intake thru-hull
fitting.
2. Use of the seawater pump to pump antifreeze solution
through the system and discharging through the
overboard thru-hull fitting. Close sea cock, remove
hose from strainer discharge, raise hose above pump
(so pump does not lose its prime) and pour in anti-
freeze solution. Pump solution through system. The
strainer and hose to sea cock will also need to be
drained of water.
3. Use of pressurized air injected at the overboard
discharge fitting and the water being discharged
through the seawater intake fitting.
4. Use of pressurized air to force water from the intake
through the overboard discharge.
Any method that causes the antifreeze solution to flow
downward is the method of choice. By this means, the
antifreeze solution will displace any water trapped and
eliminate the possibility of freezing in hidden areas. In
addition, since the seawater pump utilizes a magnetically
driven impeller, the impeller should be removed from the
wet end assembly, wiped with an alcohol solution, and
stored in a warm, dry area until commissioning takes
place.
Note: Collect all discharged liquids and re-
cycle or dispose of in a proper manner.