315S: Installation Instructions
Manufacturer reserves the right to change, at any time, specifications and designs without notice and without obligations.
8
Final Wiring Check
IMPORTANT:  Check  factory  wiring  and  field  wire  connections    to
ensure terminations are secured properly. Check wire routing to ensure
wires are not in contact with tubing, sheet metal, etc.
Compressor Crankcase Heater
When  equipped  with  a  crankcase  heater,  furnish  power  to  heater  a
minimum of 24 hr before starting unit. To furnish power to heater only,
set thermostat to OFF and close electrical disconnect to outdoor unit. 
A crankcase heater is required if refrigerant tubing is longer than 80 ft.
(24 m) or when outdoor unit is 35 ft. (6 m) below indoor unit. Refer to
the Residential Piping and Longline Guideline and Service Manual.
Install Electrical Accessories
Refer  to  the  individual  instructions  packaged  with  kits  or  accessories
when installing.
Start-Up
Follow these steps to properly start up system:
1. After  system  is  evacuated,  fully  open  liquid  and  vapor  service
valves. 
2. Unit is  shipped  with valve  stem(s)  front  seated (closed) and  caps
installed. Replace  stem  caps  after  system  is  opened  to  refrigerant
flow.  Replace  caps  finger-tight  and  tighten  with  wrench  an
additional 1/12 turn. 
3. Close electrical disconnects to energize system. 
4. Set  room  thermostat  at  desired  temperature.  Be  sure  set  point  is
below indoor ambient temperature.
5. Set  room  thermostat  to  COOL  and  fan  control  to  ON  or AUTO
mode,  as  desired.  Operate  unit  for  15  minutes.  Check  system
refrigerant charge.
Sequence of Operation
Turn on power to indoor and outdoor units. Transformer is energized. 
On a call for cooling, thermostat  makes circuits R-Y  and R-G. Circuit
R-Y  energizes  contactor,  starting  outdoor  fan  motor  and  compressor
circuit. R-G energizes indoor  unit blower  relay, starting indoor blower
motor on high speed. 
When thermostat is satisfied, its contacts open, de-energizing contactor
and blower relay. Compressor and motors should stop. 
If  indoor  unit  is  equipped  with  a  time-delay  relay  circuit,  the  indoor
blower will run up to 90 seconds to increase system efficiency.
Check Charge
Factory charge amount and desired subcooling are shown on unit rating
plate. Charging method is shown on information plate inside unit. 
For TXV, use subcooling method. For piston, use superheat method.To
properly  check  or  adjust  charge,  conditions  must  be  favorable  for
subcooling  charging.  Favorable  conditions  exist  when  the  outdoor
temperature is between 70°F and 100°F (21°C and 38°C), and the indoor
temperature  is  between  70°F  and  80°F  (21°C  and  27°C).  Follow  the
procedure below:
Unit  is  factory  charged  for  15ft  (4.57  m)  of lineset. Adjust  charge  by
adding or removing 0.6 oz/ft of 3/8 liquid line above or below 15 ft. (4.6
m) respectively.
Allow system to operate at least 15 minutes. If conditions are favorable,
check system charge by super heat method for fixed metering device and
subcooling  method  for  TXV.  If  any  adjustment  is  necessary,  adjust
charge slowly  and  allow  system  to  operate  for  15  minutes  to  stabilize
before declaring a properly charged system. 
If  the  indoor  temperature  is  above  80°F  (27°C),  and  the  outdoor
temperature  is  in  the favorable  range,  adjust  system  charge  by weight
based on line length and allow the indoor temperature to drop to 80°F
(27°C) before attempting to check system charge by subcooling method
as described above. 
If  the  indoor  temperature  is  below  70°F  (21°C),  or  the  outdoor
temperature is not in the favorable range, adjust charge for line set length
above  or  below  15  ft.  (4.6  m)  only.  Charge  level  should  then  be
appropriate  for  the  system  to  achieve  rated  capacity.  The  charge  level
could then be checked at another time when the both indoor and outdoor
temperatures are in a more favorable range.
NOTE: If line length is beyond 80 ft (24 m) or greater than 35 ft (11 m)
vertical separation, See Residential Piping and Long Line Guideline for
special charging requirements.
CAUTION
!
UNIT OPERATION AND SAFETY HAZARD
Failure to follow this caution may result in personal injury, equipment
damage or improper operation.
• Do not overcharge system with refrigerant.
• Do not operate unit in a vacuum or at negative pressure.
• Compressor dome temperatures may be hot.
CAUTION
!
PERSONAL INJURY HAZARD
Failure to follow this caution may result in personal  injury.
Wear  safety  glasses,  protective  clothing,  and  gloves  when  handling
refrigerant and observe the following:
• Front seating service valves are equipped with Schrader valves.