Microchannel Heat Exchanger (Mchx) Condenser Coil Maintenance And Cleaning; Recommendations - Carrier AQUAFORCE 30XA080-500 Controls, Start-Up, Operation, Service And Troubleshooting Instructions

heater tapes on the cooler and the cooler is drained, open
the circuit breaker for the heater, CB-13 or shut off power
during off-season shutdown.
2. Draining the fluid from the system is highly recommend-
ed. If the unit is equipped with a hydronic package, there
are additional drains in the pump housing and strainer
that must be opened to allow for all for all of the water to
drain.
3. Isolate the cooler from the rest of the system with water
shutoff valves.
4. Replace the drain plug and completely fill the cooler with
a mixture of water and a suitable corrosion-inhibited anti-
freeze solution such as propylene glycol. The concentra-
tion should be adequate to provide freeze protection to
15° F (8.3° C) below the expected low ambient tempera-
ture conditions. Antifreeze can be added through the vent
on top of the cooler. If the unit has a hydronic pump pack-
age, the pump must be treated in the same manner.
5. Leave the cooler filled with the antifreeze solution for the
winter, or drain if desired. Be sure to deenergize heaters
(if installed) as explained in Step 1 to prevent damage.
Use an approved method of disposal when removing anti-
freeze solution.
L1
BRN
WHT
24 VAC
BLK
N
BLU
Fig. 59 — Chilled Water Flow Switch
OUT
FLOW SWITCH
STANDARD FLOODED COOLER
Fig. 60 — Flow Switch
a30-5334
1
2
4
3
a30-5335
IN
85
At the beginning of the next cooling season, be sure that
there is refrigerant pressure on each circuit before refilling
cooler, add recommended inhibitor, and reset the CB-HT (cir-
cuit breaker heater) (if opened) or restore power.
Microchannel Heat Exchanger (MCHX) Con-
denser Coil Maintenance and Cleaning Rec-
Routine cleaning of coil surfaces is
ommendations —
essential to maintain proper operation of the unit. Elimination
of contamination and removal of harmful residues will greatly
increase the life of the coil and extend the life of the unit. The
following steps should be taken to clean MCHX condenser
coils:
CAUTION
Do not apply any chemical cleaners to MCHX condenser
coils. These cleaners can accelerate corrosion and damage
the coil.
1. Remove any foreign objects or debris attached to the coil
face or trapped within the mounting frame and brackets.
2. Put on personal protective equipment including safety
glasses and/or face shield, waterproof clothing and
gloves. It is recommended to use full coverage clothing.
3. Start high pressure water sprayer and purge any soap or
industrial cleaners from sprayer before cleaning condens-
er coils. Only clean potable water is authorized for clean-
ing condenser coils.
4. Clean condenser face by spraying the coil steady and uni-
formly from top to bottom while directing the spray
straight toward the coil. Do not exceed 900 psig
(6205 kPa) or 30 degree angle. The nozzle must be at
least 12 in. (304.8 mm) from the coil face. Reduce pres-
sure and use caution to prevent damage to air centers.
CAUTION
Excessive water pressure will fracture the braze between
air centers and refrigerant tubes.
RTPF (Round Tube Plate Fin) Condenser Coil
Maintenance and Cleaning Recommenda-
Routine cleaning of coil surfaces is essential to
tions —
maintain proper operation of the unit. Elimination of contami-
nation and removal of harmful residues will greatly increase
the life of the coil and extend the life of the unit. The following
maintenance and cleaning procedures are recommended as part
of the routine maintenance activities to extend the life of the
coil.
REMOVE SURFACE LOADED FIBERS — Surface load-
ed fibers or dirt should be removed with a vacuum cleaner. If a
vacuum cleaner is not available, a soft non-metallic bristle
brush may be used. In either case, the tool should be applied in
the direction of the fins. Coil surfaces can be easily damaged
(fin edges can be easily bent over and damage to the coating of
a protected coil) if the tool is applied across the fins.
NOTE: Use of a water stream, such as a garden hose, against a
surface loaded coil will drive the fibers and dirt into the coil.
This will make cleaning efforts more difficult. Surface loaded
fibers must be completely removed prior to using low velocity
clean water rinse.
PERIODIC CLEAN WATER RINSE — A periodic clean
water rinse is very beneficial for coils that are applied in coastal
or industrial environments. However, it is very important that
the water rinse is made with very low velocity water stream to
avoid damaging the fin edges. Monthly cleaning as described
below is recommended.