Evaporator Coil; Refrigeration System Components; Evaporator Coil Metering Devices - Carrier 50GCQ Series Service And Maintenance Instructions

debris. If a coil cleaner is used be sure to rinse the coils
completely before reassembly.
11. Move the inner coil back into position. Reinstall the lower
and upper coil clips. Reinstall the top panel and replace all
screws.
Totaline Environmentally Balanced Coil Cleaner Application
Equipment
• 2-1/2 gallon garden sprayer
• Water rinse with low velocity spray nozzle
CAUTION
UNIT DAMAGE HAZARD
Failure to follow this caution may result in reduced unit
performance or unit shutdown.
High velocity water from a pressure washer, garden hose, or
compressed air should never be used to clean a coil. The force
of the water or air jet will bend the fin edges and increase
airside pressure drop.
CAUTION
UNIT DAMAGE HAZARD
Failure to follow this caution may result in accelerated
corrosion of unit parts.
Harsh chemicals, household bleach or acid or basic cleaners
should not be used to clean outdoor or indoor coils of any kind.
These cleaners can be very difficult to rinse out of the coil and
can accelerate corrosion at the fin/tube interface where
dissimilar materials are in contact. If there is dirt below the
surface of the coil, use the environmentally balanced coil
cleaner.
Totaline Environmentally Balanced Coil Cleaner Application
Instructions
1. Proper eye protection such as safety glasses is recom-
mended during mixing and application.
2. Remove all surface loaded fibers and dirt with a vacuum
cleaner as described above.
3. Thoroughly wet finned surfaces with clean water and a
low velocity garden hose, being careful not to bend fins.
4. Mix Totaline environmentally balanced coil cleaner in a
2-1/2 gallon garden sprayer according to the instructions
included with the cleaner. The optimum solution tempera-
ture is 100°F.
NOTE: DO NOT USE water in excess of 130°F, as the enzymatic
activity will be destroyed.
5. Thoroughly apply Totaline environmentally balanced coil
cleaner solution to all coil surfaces including finned area,
tube sheets and coil headers.
6. Hold garden sprayer nozzle close to finned areas and apply
cleaner with a vertical, up-and-down motion. Avoid spraying
in horizontal pattern to minimize potential for fin damage.
7. Ensure cleaner thoroughly penetrates deep into finned
areas. Interior and exterior finned areas must be thor-
oughly cleaned. Finned surfaces should remain wet with
cleaning solution for 10 minutes. Ensure surfaces are not
allowed to dry before rinsing. Reapply cleaner as needed
to ensure 10-minute saturation is achieved.
8. Thoroughly rinse all surfaces with low velocity clean
water using downward rinsing motion of water spray noz-
zle. Protect fins from damage from the spray nozzle.

Evaporator Coil

Cleaning the Evaporator Coil:
1. Turn unit power off. Install lockout tag. Remove evapora-
tor coil access panel.
2. If economizer or two-position damper is installed, remove
economizer by disconnecting Molex
mounting screws.
3. Slide filters out of unit.
4. Clean coil using a commercial coil cleaner or dishwasher
detergent in a pressurized spray canister. Wash both sides
of coil and flush with clean water. For best results, back-
flush toward return-air section to remove foreign material.
Flush condensate pan after completion.
5. Reinstall economizer and filters.
6. Reconnect wiring.
7. Replace access panels.

Refrigeration System Components

Each heat pump refrigeration system includes a compressor, accu-
mulator, reversing valve, dual-function outdoor coil with vapor
header check valve, cooling liquid line with a filter drier and a
check valve, dual-function indoor coil with a vapor header check
valve, and heating liquid line with a check valve and a strainer.
50GCQ*04-06 units have a single compressor-circuit. See Fig. 19
and Tables 3-5 for typical unit piping schematic. Dual-function
outdoor and indoor coils are designed to provide parallel coil cir-
cuits during evaporator-function operation and converging coil
circuits during the condenser-function operation.
Table 3 — Cooling Mode (each circuit)
COMPONENT
Reversing Valve
Check Valve A
Check Valve B
Check Valve C
Check Valve D
Table 4 — Heating Mode (each circuit)
COMPONENT
Reversing Valve
Check Valve A
Check Valve B
Check Valve C
Check Valve D
Table 5 — Defrost Mode
COMPONENT
Defrost Thermostat
Outdoor Fan(s)
Reversing Valve
Check Valve A
Check Valve B
Check Valve C
Check Valve D

Evaporator Coil Metering Devices

50GCQ*04-06 units use a TXV-distributer system for evaporator
metering.
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owners.
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plug and removing
®1
STATUS/POSITION
Energized
Closed
Open
Closed
Open
STATUS/POSITION
De-energized
Open
Closed
Open
Closed
STATUS/POSITION
Closed
Off
Energized
Closed
Open
Closed
Open