Carrier 48HC D17 Series Service And Maintenance Instructions page 11

as the enzymatic activity will be destroyed.
5. Thoroughly apply Totaline environmentally sound
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.
7. Avoid spraying in horizontal pattern minimizing the
potential for fin damage.
8. Ensure cleaner thoroughly penetrates deep into finned
areas.
9. Interior and exterior finned areas must be thoroughly
cleaned.
10. Finned surfaces should remain wet with cleaning
solution for 10 minutes.
11. Ensure surfaces are not allowed to dry before rinsing.
Reapply cleaner as needed to ensure 10- - minute satur-
ation is achieved.
12. Thoroughly rinse all surfaces with low velocity clean
water using downward rinsing motion of water spray
nozzle. Protect fins from damage from the spray
nozzle.
Evaporator Coil Metering Devices
The metering devices are multiple fixed- - bore devices
(Acutrolt) sweated into the horizontal outlet tubes from
the liquid header, located at the entrance to each
evaporator coil circuit path. The metering devices are
non- - adjustable. Service requires replacing the entire
liquid header assembly.
To check for possible blockage of one or more of these
metering devices, disconnect the supply fan contactor
(IFC) coil, then start the compressor and observe the
frosting pattern on the face of the evaporator coil.
A frost pattern should develop uniformly across the face
of the coil starting at each horizontal header tube. Failure
to develop frost at an outlet tube can indicate a plugged or
a missing orifice.
Refrigerant System Pressure Access Ports
There are two access ports in the system - - on the suction
tube near the compressor and on the discharge tube near
the compressor. These are brass fittings with black plastic
caps. The hose connection fittings are standard 1/4 SAE
male flare couplings.
The brass fittings are two- - piece High Flow valves, with a
receptacle base brazed to the tubing and an integral
spring-closed check valve core screwed into the base. See
Fig. 14. This schrader valve is permanently assembled
into the core body and cannot be serviced separately;
replace the entire core body if necessary. Service tools are
available from RCD (P920- - 0010) that allow the
replacement of the schrader valve core without having to
recover the entire system refrigerant charge. Apply
compressor refrigerant oil to the schrader valve core's
bottom O-ring. Install the fitting body with 96
(10.85  1.13Nm) of torque; do not overtighten.
NOTE: The High Flow valve has a black plastic cap with
a rubber o- - ring located inside the cap. This rubber o- - ring
must be in place in the cap to prevent refrigerant leaks.
11
 10 in-lbs