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START-UP
Before starting unit, check the following and correct as
necessary:
•
Is unit solidly supported?
•
Is fan adjusted for speed and pulley alignment?
•
Are pulleys, motor, and bearings securely mounted?
•
Are there any loose parts that will rattle or vibrate?
•
Is condensate drain pan pitched for correct drainage?
•
Are coil baffle plates tight against coil to prevent air
bypass?
•
Are all panels securely fastened?
•
Are all electrical connections correct and tight?
•
Are there any loose or disconnected wires at the VFD
or in the control box? Are any wires in contact with
sharp edges or moving parts (e.g., pulley, belt, etc.)?
•
Have all safety, caution, and warning labels been
read?
FAS/FHS ONLY
•
Is TXV bulb located on suction tube per Fig. 26?
•
Is the capillary tube to the bulb free of kinks and not
subject to pinching?
•
Is the bulb well secured to the suction tube with
strap?
Also refer to condensing unit or outdoor heat pump section
instructions before starting a split system. A split system
start-up checklist is provided at the end of these
instructions.
IMPORTANT! / IMPORTANT
TXV
SENSING
UPPER SPLIT
BULB
BLOC SUPÉRIEUR
CAPTEUR TXV
AIR FLOW
CIRCULATION
15 DIAMS MIN
10 DIAMS
D'AIR
10 x DIA. MIN
15 x DIA. MIN
LOWER
SPLIT
BLOC
TXV SENSING
INFÉRIEUR
BULB
CAPTEUR TXV
AIR FLOW
CIRCULATION
D'AIR
15 DIAMS MIN
10 DIAMS
15 x DIA. MIN
10 x DIA. MIN
The sensor bulb capillary tubes must be routed from the TXVs inside the unit through one of the piping
access holes. Clamp the TXV sensor bulb on a vertical portion of the suction line, outside the unit.
Super heat must be adjusted in field.
Les tubes capillaires du capteur doivent être acheminé à partir du détendeur thermostatique situé à l'intérieur
de l'appareil au travers de l'un des trous d'accès de conduites. Attacher le capteur sur une portion verticale
de la conduite de succion, à l'extérieur de l'appareil. La surchauffe doit être ajustée sur place.
Fig. 26 — TXV Bulb Location Label
Adjusting TXV for Superheat (FAS/FHS only)
The unit-mounted thermostatic expansion valve(s) is/are
factory set to provided superheat at the bulb location in 10°F
to 15°F (5.5°C to 8.3°C) range. Actual system load condi-
tions may require adjustment of the factory setting. (See
Fig. 27.)
To adjust the TXV superheat setting:
1. Remove the seal cap from the bottom of the TXV body.
2. To increase superheat, turn the stem clockwise. To
decrease the superheat, turn the stem counterclock-
wise. Do not turn the stem more than one full turn.
FAS-FHS-240-336-02SI
40RU500072 2.0
EQUALIZER LINE
CONDUITE D'ÉQUILIBRAGE
SIGHT GLASS
HUBLOT
TXV
SOLENOID
8 DIAMS MIN
VALVE
8 x DIA. MIN
VANNE
SOLÉNOÏDE
FILTER
DRIER
FILTRE
DESSICCATEUR
TXV
EQUALIZER LINE
CONDUITE D'ÉQUILIBRAGE
8 DIAMS MIN
8 x DIA. MIN
INDOOR COIL
ÉCHANGEUR INTÉRIEUR
Specifications subject to change without notice.
3. Wait until suction pressure and superheat stabilize. This
may take more than 30 minutes.
4. Continue adjustment until superheat reaches 10°F to
15°F (5.5°C to 8.3°C).
5. Replace the seal cap; tighten.
INSTALLER / INSTALLATEUR
TXV superheat must be checked at initial
unit start-up and adjusted if necessary.
Superheat must be 10 - 15 deg F.
La surchauffe TXV doit être vérifiée au
moment de la mise en route initiale et
ajustée si nécessaire. La surchauffe doit
être comprise entre 10 et 15 degrés F.
Fig. 27 — TXV Adjustment Label
Compressor Rotation
Follow instructions in Condensing Unit installation instruc-
tions. For units equipped with a VFD on the indoor fan mo-
tor, the rotation direction of the indoor fan motor and fan
cannot be used to visually confirm a correct phase connec-
tion to the unit and compressors. Correct phases to equip-
ment for proper compressor rotation. The VFD will maintain
the same rotation as input phases are changed. Pressure
gages MUST BE USED during cooling system start-up to
confirm correct compressor rotation and operation.
Indoor Fan Motor
Raise the cooling set point at the space thermostat to higher
than the space temperature. Switch the thermostat's FAN
switch to the CONT (Continuous) position. The fan motor
will start and run at reduced speed. Check for fan rotation
direction. To reverse the fan rotation, disconnect all power to
the unit and then switch two motor power leads between the
VFD and the motor. Restore unit power and recheck the fan
rotation direction.
Check fan motor speed. Motor shaft should be rotating at
1150 to 1180 rpm (19.2 to 19.7 r/s).
Switch the thermostat's FAN switch to AUTO position. Fan
motor will stop.
Cooling with 2-Speed Indoor Fan Motor
System
FIRST STAGE (Y1)
Set the thermostat FAN switch to AUTO and the SYSTEM
switch to COOL. Slowly lower the cooling set point until first
stage compressor starts. Indoor fan motor also starts and
runs at reduced speed.
SECOND STAGE (Y2)
Lower the cooling set point until the second stage compres-
sor starts. The indoor fan speed is dependent on the num-
ber of cooling stages:
•
2-Stage Systems: The indoor fan motor will switch to
high speed.
•
3-Stage Systems: The indoor fan motor will remain at
low speed.
THIRD STAGE (Y3) — 3-STAGE SYSTEMS ONLY
Lower the cooling set point until the third stage compressor
starts. The indoor fan motor will switch to high speed.
Check the fan motor speed. Motor shaft should be rotating
at 1725 to 1760 rpm (28.8 to 29.3 r/s).
Confirm compressors are running at correct rotation by
checking suction and discharge pressures. To reverse the
40RU500073 2.0
27
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