70
 
Return-Air Filters
Ensure correct filters are installed in unit (see Appendix B - Physi-
cal Data). Do not operate unit without return-air filters.
Outdoor-Air Inlet Screens
Outdoor-air inlet screen must be in place before operating unit.
Compressor Mounting
Compressors are internally spring mounted. Do not loosen or re-
move compressor hold down bolts.
Internal Wiring
Check all electrical connections in unit control boxes. Tighten as
required.
Refrigerant Service Ports
Each unit system has two 
1
/
4
-in. SAE  flare (with check valves)
service ports: one on the suction line, and one on the compressor
discharge line. Be sure that caps on the ports are tight.
Compressor Rotation
On 3-phase units with scroll compressors, it is important to be cer-
tain compressor is rotating in the proper direction. To determine
whether or not compressor is rotating in the proper direction:
1. Connect service gages  to suction  and discharge pressure
fittings.
2. Energize the compressor.
3. The suction pressure should drop and the discharge pressure
should rise, as is normal on any start-up.
If the suction pressure does not drop and the discharge pressure
does not rise to normal levels:
4. Note that the evaporator fan is probably also rotating in the
wrong direction.
5. Turn off power to the unit and install lockout tag.
6. Reverse any two of the unit power leads.
7. Re-energize to the compressor. Check pressures.
The  suction  and  discharge  pressure levels should  now move to
their normal start-up levels.
NOTE: When the compressor is rotating in the wrong direction,
the unit will make an elevated level of noise and will not provide
cooling.
Cooling
Set space thermostat to OFF position. To start unit, turn on main
power supply. Set system selector switch at COOL position and
fan switch at AUTO. position. Adjust thermostat to a setting be-
low room temperature. Compressor starts on closure of contactor.
Check unit charge. Refer to Refrigerant Charge section.
Reset  thermostat at a  position  above room  temperature. Com-
pressor  will  shut  off.  Evaporator  fan  will  shut  off  after  a
30 second delay.
To shut off unit, set system selector switch at OFF position. Reset-
ting thermostat at a position above room temperature shuts unit off
temporarily until space temperature exceeds thermostat setting.
Main Burners
Main burners are factory set and should require no adjustment.
To  check  ignition  of main  burners  and  heating  controls,  move
thermostat  setpoint above room  temperature  and verify that  the
burners light and evaporator fan is energized. Check heating ef-
fect, then lower the thermostat setting below the room temperature
and verify that the burners and evaporator fan turn off.
Refer to Tables 16 and 17 for the correct orifice to use at high
altitudes.
Heating
1. Purge gas supply line of air by opening union ahead of the gas
valve.  If  gas  odor  is  detected,  tighten  union  and  wait
5 minutes before proceeding.
2. Turn on electrical supply and manual gas valve.
WARNING
FIRE, EXPLOSION HAZARD
Failure to  follow  this warning could result  in death, serious
personal injury and/or property damage.
Disconnect gas piping from unit when pressure testing at pres-
sure  greater  than  0.5 psig  (3450  Pa).  Pressures  greater  than
0.5 psig will cause gas valve damage  resulting in hazardous
condition.  If gas  valve  is  subjected  to pressure  greater  than
0.5 psig, it must be replaced before use. When pressure testing
field-supplied gas piping at pressures of 0.5 psig or less, a unit
connected to such piping must be isolated by closing the man-
ual gas valve(s).
WARNING
If the information in this manual is not followed exactly, a fire
or explosion may result causing property damage, personal in-
jury or loss of life.
Do not store or use gasoline or other flammable vapors and
liquids in the vicinity of this or any other appliance.
WHAT TO DO IF YOU SMELL GAS
• Do not try to light any appliance.
• Do  not  touch  any  electrical  switch;  do  not  use  any
phone in your building.
• Immediately call your gas supplier from a neighbor’s
phone. Follow the gas supplier’s instructions.
• If  you  cannot  reach  your  gas  supplier,  call  the  fire
department.
Installation and service must be performed by a qualified in-
staller, service agency or the gas supplier.
AVERTISSEMENT
RISQUE D´INCENDIE OU D´EXPLOSION
Si les consignes de sécurité ne sont pas suivies à la lettre, cela
peut entraîner la mort, de graves blessures ou des dommages
matériels.
Ne pas entreposer ni utiliser d´essence ni autres vapeurs ou liq-
uides inflammables à proximité de cet appareil ou de tout autre
appareil.
QUE FAIRE SI UNE ODEUR DE GAZ EST DÉTECTÉE
• Ne mettre en marche aucun appareil.
• Ne  toucher  aucun  interrupteur  électrique;  ne  pas
utiliser de téléphone dans le bâtiment.
• Quitter le bâtiment immédiatement.
• Appeler  immédiatement  le  fournisseur  de  gaz  en
utilisant  le  téléphone  d´un  voisin.  Suivre  les
instructions du fournisseur de gaz.
• Si le fournisseur de gaz n´est pas accessible, appeler le
service d´incendie.
L´installation et l´entretien doivent être effectués par un instal-
lateur ou une entreprise d´entretien qualifié, ou le fournisseur
de gaz.