Preparation For Winter Shutdown; Microchannel Heat Exchanger (Mchx) Condenser Coil Maintenance And Cleaning; Recommendations - Carrier AquaForce 30XV140 Controls, Start-Up, Operation, Service And Troubleshooting Instructions

CAUTION
Water must be within design flow limits, clean and treated
to ensure proper machine performance and reduce the
potential of tubing damage due to corrosion, scaling, and
algae. Carrier assumes no responsibility for evaporator
damage resulting from untreated or improperly treated
water.
PREPARATION FOR WINTER SHUTDOWN —
unit is not operational during the winter months, at the end of
the cooling season complete the following steps.
CAUTION
Failure to remove power before draining heater equipped
evaporators can result in heater damage.
Evaporator to be drained for winter shutdown
1. To prepare the system for winter shutdown, draining the
fluid from the system is highly recommended. Isolate the
evaporator from the rest of the system with water shutoff
valves. Be sure to deenergize heaters (if installed) by
opening circuit breaker (CB-7) or shut off power to the
chiller to prevent damage if the evaporator is drained.
2. Remove the evaporator drain plug. Follow all local codes
and regulations regarding the fluid disposal.
3. Once fully drained, replace the drain plug(s) and com-
pletely fill the evaporator, and hydronic package if
equipped, with suitable corrosion-inhibited antifreeze
solution such as propylene glycol. The concentration
should be adequate to provide freeze protection to 15° F
(8.3° C) below the expected low ambient temperature
conditions. Antifreeze can be added through the vent on
top of the evaporator head. Evaporator fluid volumes can
be found in the Installation Instructions for the unit.
4. Leave the evaporator filled with the antifreeze solution
for the winter to provide corrosion protection during
the off season. The evaporator may be drained if de-
sired. Follow all local codes and regulations regarding
the fluid disposal.
5. At the beginning of the next cooling season, be sure that
there is refrigerant pressure in each circuit before refilling
evaporator, add recommended inhibitor, and reset the cir-
cuit breaker for the heater (CB-7) if opened or restore
power.
Evaporator to remain filled for winter shutdown
1. If the evaporator will not be drained, do not shut off pow-
er disconnect during off-season shutdown.
2. If the chilled water loop is not protected with a suitable
corrosion-inhibited antifreeze solution such as propylene
glycol, the unit must have evaporator pump control. In
the event of a power failure with sub-freezing tempera-
tures, the unit will not have any evaporator freeze protec-
tion and may be subject to damage.
CAUTION
Operation or winter shutdown with fresh water is not fail-
safe should there be a loss of power to the chiller or to the
circulating pump. Freeze damage due to power loss or dis-
abling chiller pump control in fresh water systems will
impair or otherwise negatively affect the warranty.
3. It is recommended that the loop be protected with a
suitable corrosion-inhibited antifreeze solution such as
propylene glycol. The concentration should be ade-
quate to provide freeze protection to 15° F (8.3° C) be-
low the expected low ambient temperature conditions.
Evaporator heaters will not protect the evaporator from
freeze-up in the event of power loss.
Microchannel Heat Exchanger (MCHX) Con-
denser Coil Maintenance and Cleaning Rec-
ommendations —
If the
essential to maintain proper operation of the unit. Elimina-
tion 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:
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. Full coverage clothing is recommended.
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), 104 F (40 C) water temperature, or 45 degree
angle. The nozzle must be at least 12 in. (304.8 mm) from
the coil face. Reduce pressure and use caution to prevent
damage to air centers.
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 con-
tamination and removal of harmful residues will greatly in-
crease the life of the coil and extend the life of the unit. The
following maintenance and cleaning procedures are recom-
mended as part of the routine maintenance activities to ex-
tend 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
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Routine cleaning of coil surfaces is
CAUTION
CAUTION