2
5. Assemble the two halves of coil header plate over the coil
tubes and fasten together using supplied screws. (On
some furnace models, the top edge of the upper half of the
header plate may need to be bent for proper screw hole
alignment.)
6. Slide rubber grommets into place around coil tubes and
into coil header plate holes.
7. Position rails inside furnace as shown in Fig. 1. Slide coil
into furnace, nesting drain pan inside rails. (On some
furnace models, the tabs on the rails may need to be bent
up for proper fit.)
8. Align furnace inner shield (removed earlier) with coil
header plate so that the refrigerant tubes fit through the
knockouts. Fasten shield to header plates using supplied
screws.
9. Replace furnace front access doors.
A05435
Fig. 1 Rails and Coil Installation
PROCEDURE 3 — CONNECT REFRIGERANT TUBING
See Table 1 for coil connection sizes. Outdoor units may be
connected to indoor sections using the field--supplied
refrigerant--grade tubing of correct size and condition.
Table 1—Coil Connection Tube Size (In.)
Model Number
Liquid
Suction
CN(P,R)FU2418ACA
3/8
5/8
CN(P,R)FU3618ACA
3/8
3/4
CN(P,R)FU4818ACA
3/8
3/4
UNIT OR PROPERTY DAMAGE HAZARD
Failure to follow this caution may result in equipment
damage or improper operation.
If undersized, damaged, or elliptically shaped tubing is used
when making connections, leaks may result.
CAUTION
!
When tubing package is used and mechanical connections are
made within 60 sec, coils do not require evacuation. Entire
suction tube must be insulated to prevent condensate damage
within furnace cabinet.
Connect refrigerant liquid and suction tubes to compatible fittings
on coil, using backup wrenches. Make suction tube connection
first, then liquid tube connection.
For a mix--match system, use suction tube sizes recommended in
outdoor unit Installation Instructions.
A. Mechanical Connection
1. Loosen lock nut on compatible fitting one turn. Do not
remove. (See Fig. 2.)
LOCKNUT
O-RING
RUBBER
PLUG
A86154
Fig. 2 Compatible Fitting
2. Remove plug making sure O--ring is in the groove inside
compatible fitting.
3. Cut tubing to correct length. Insert tube into compatible
fitting until it bottoms.
4. Keep compatible fitting bottomed. Tighten lock nut using
backup wrench until it contacts back of coupling flange.
B. Refrigerant Metering Device
1. CNPFU MODELS -- These coils have a factory--installed
hard shut--off TXV designed only for use with Puron
,
R--410A, refrigerant.
Use only with outdoor units
designed for Puron
refrigerant, R--410A.
2. CNRFU MODELS -- These coils have a factory--installed
hard shut--off TXV designed only for use with R--22
refrigerant. Use only with outdoor units designed for
R--22.
NOTE
:
All TXVs have preset superheat settings and are not
field adjustable.
Carefully remove TXV bulb insulation and verify that the TXV
bulb is securely fastened with hose clamp. Tighten screw a
half--turn past hand tight with TXV bulb placed in the indentation
with full contact with the vapor line tube. Re--wrap TXV bulb
with insulation.
PROCEDURE 4 — INSTALL CONDENSATE DRAIN
Coil is provided with two 3/4 in. NPT condensate drain
connections.
The lower connection is the primary drain, and
the higher connection is the secondary (overflow) drain
.
Coil is provided with flexible drain tubing, 90
combination
fitting, and P--trap. (See Fig. 3.)
1. Thread the 90
combination fitting into the primary (lower)
drain. Use pipe dope and do not over tighten.
2. Determine where the P--trap will be placed. NOTE: Keep
the P--trap as close to the coil as possible. P--trap must be
positioned lower than the bottom of the drain pan. (See Fig.
3.)
3. Cut a length of the flexible tubing and install it from the 90
combination fitting to the P--trap.
4. Install the remainder of the flexible tubing to the outlet side
of the P--trap and route the tubing to the outside. Check local
codes before connecting to a waste (sewer) line.
CNP
F
/C
NR
F
