278410-UIM-K-1010
Johnson Controls Unitary Products
7
4.
Wrap a water soaked rag around the coil connection tubes inside
the cabinet to avoid damaging the TXV bulb.
5.
Remove grommets where tubes exit the cabinet to prevent burning
them during brazing.
6.
Purge refrigerant lines with dry nitrogen.
7.
Braze the suction and liquid lines.
8.
Remove the heat shield.
9.
Re-attach the grommets to the lines carefully to prevent air leak-
age.
10. Attach the coil access panel to the cabinet.
Refer to Outdoor unit Installation Manual for evacuation, leak check and
charging instructions.
Lines should be sound isolated by using appropriate hangers or strap-
ping.
All evaporator coil connections are copper-to-copper and should be
brazed with a phosphorous-copper alloy material such as Silfos-5 or
equivalent. DO NOT use soft solder.
DRAIN CONNECTIONS
All drain lines should be trapped a minimum of three inches, should be
pitched away from unit drain pan and should be no smaller than the coil
drain connection.
Route the drain line so that it does not interfere with accessibility to the
coil, air handling system or filter and will not be exposed to freezing
temperatures. See Figures 2 and 3 for drain connection locations.
Coils should be installed level or pitched slightly toward the drain end.
Suggested pitch should not exceed 1/4 inch per foot of coil.
The coil is provided with a secondary drain that should be trapped and
piped to a location that will give the occupant a visual warning that the
primary drain is clogged. If the secondary drain is not used it must be
capped.
The drain pan connections are designed to ASTM Standard D 2466
Schedule 40. Use 3/4" PVC or steel threaded pipe. Since the drains are
not subject to any pressure it is not necessary to use Schedule 40 pipe
for drain lines.
DO NOT use teflon tape, “pipe dope”, or other sealants. The use of a
sealant may cause damage and premature failure of the drain pan.
SECTION IV: ELECTRIC HEATER
INSTALLATION
If the air handler requires electric heat, install the electric heat kit
according to the installation instructions included with the kit. After
installing the kit, mark the air handler nameplate to designate the heater
kit that was installed. If no heater is installed, mark the name plate
appropriately to indicate that no heat kit is installed.
The HEAT ENABLE jumper (See Figure 11) must be moved to the
HEAT position to enable operation of the heater.
Use only 4HK heater kits, as listed on Air Handler name plate and in
these instructions. Use data from Tables 10 through 15 for information
on required minimum motor speed tap to be used for heating operation,
maximum over-current protection device required and minimum electri-
cal supply wiring size required – for listed combination of Air Handler
and Heater Kit.
For upflow, downflow and horizontal right hand applications the kits can
be installed without modification.
Field modification is required for horizontal left hand airflow application
only. Follow instructions with heater for modification.
Threaded drain connection should be hand-tightened, plus no more
than 1/16 turn.
When the coil is installed in an attic or above a finished ceiling, an
auxiliary drain pan should be provided under the coil if specified by
local building codes. When this exterior secondary drain pan is
used that drain should be piped to a location that will give the occu-
pant a visual warning that the primary drain is clogged.
FIGURE 11:
Control Board
HEAT ENABLE
JUMPER
HUM OUT
RELAY OUTPUT
EAC RELAY
OUTPUT
LOW FAN
RELAY OUTPUT
SPARE
JUMPER
HUM STAT JUMPER
MODE JUMPER
FUSE