53
Compressor Rotation
On 3-phase units with scroll compressors, it is important to be
certain compressor is rotating in the proper direction. To deter-
mine whether or not compressor is rotating in the proper direc-
tion:
1. Connect service gages to suction and discharge pressure
fittings.
2. Energize the compressor.
3. The suction pressure should drop and the discharge pres-
sure 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:
1. Note that the evaporator fan is probably also rotating in
the wrong direction.
2. Turn off power to the unit and install lockout tag.
3. Reverse any two of the unit power leads.
4. 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 posi-
tion and fan switch at AUTO. position. Adjust thermostat to a
setting below room temperature. Compressor starts on closure
of contactor.
Check unit charge. Refer to Refrigerant Charge section on
page 14.
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.
Resetting thermostat at a position above room temperature
shuts unit off temporarily until space temperature exceeds ther-
mostat setting.
Heating
To start unit, turn on main power supply. Set system selector
switch to the HEAT position and set thermostat at a setting
above room temperature. Set fan to AUTO position.
First stage of thermostat energizes the first stage of the electric
heaters. Second stage of thermostat energizes the second stage
of electric heaters (if installed). Check heating effects at air
supply grille(s).
If electric heaters do not energize, reset limit switch (located on
supply-fan scroll) by pressing button located between termi-
nals on the switch.
To shut unit off, set system selector switch to the OFF position.
Resetting thermostat at a position below room temperature
temporarily shuts unit off until space temperature falls below
thermostat setting.
Ventilation (Continuous Fan)
Set fan and system selector switches at ON and OFF positions,
respectively. Evaporator fan operates continuously to provide
constant air circulation.
FASTENER TORQUE VALUES
Table 17 — Torque Values
START-UP, RTU OPEN CONTROLS
START-UP, SYSTEMVU CONTROLS
CAUTION
EQUIPMENT DAMAGE HAZARD
Failure to follow this caution can result in premature wear
and damage to equipment.
Scroll compressors can only compress refrigerant if rotat-
ing in the right direction. Reverse rotation for extended
times can result in internal damage to the compressor.
Scroll compressors are sealed units and cannot be repaired
on site location.
Heat shield screws
30 in.-lb (3.4 Nm) ±2 in.-lb (0.2 Nm)
Stator motor mounting
screws
23 in.-lb (2.6 Nm) ±2 in.-lb (0.2 Nm)
Fan rotor mounting
screws
23 in.-lb (2.6 Nm) ±2 in.-lb (0.2 Nm)
Limit switch screws
50 in.-lb (5.7 Nm) ±5 in.-lb (0.6 Nm)
Fan Deck bracket screws
50 in.-lb (5.7 Nm) ±5 in.-lb (0.6 Nm)
Condenser fan motor
mounting screws
30 in.-lb (3.4 Nm) ±3 in.-lb (0.3 Nm)
Condenser fan hub set
screw
60 in.-lb (6.8 Nm) ±5 in.-lb (0.6 Nm)
Compressor mounting
bolts
65 in.-lb (7.3 Nm) +10 in.-lb (1.2Nm)
IMPORTANT: SET-UP INSTRUCTIONS
Installation, wiring and troubleshooting information for
the RTU Open Controller.: “48/50FC, 48/50GC Single
Package Rooftop Units with RTU Open Controls, Start-
up, Operation and Troubleshooting Instructions.” Have a
copy of this manual available at unit start-up.
IMPORTANT: SET-UP INSTRUCTIONS
Installation, wiring and troubleshooting information for
the SystemVu™ Controller.: “48/50FC 04-07, 48/50GC
04-06 Single Package Rooftop Units with SystemVu
Controls Version 1.X Controls, Start-up, Operation and
Troubleshooting.” Have a copy of this manual available
at unit start-up.
Summary of Contents for 50FC A04 Series
Page 96: ...96 APPENDIX D WIRING DIAGRAMS Fig J 50FC 04 06 208 230 1 60 Unit with RTU Open Controller...
Page 97: ...97 APPENDIX D WIRING DIAGRAMS Fig K 50FC 04 06 208 230 3 60 Unit with RTU Open Controller...
Page 98: ...98 APPENDIX D WIRING DIAGRAMS Fig L 50FC 04 06 460 575 3 60 Unit with RTU Open Controller...
Page 99: ...99 APPENDIX D WIRING DIAGRAMS Fig M 50FC 07 208 230 Unit with RTU Open Controller...
Page 100: ...100 APPENDIX D WIRING DIAGRAMS Fig N 50FC 07 460 575 Unit with RTU Open Controller...
Page 101: ...101 APPENDIX D WIRING DIAGRAMS Fig O 50FC 04 06 Power Wiring Diagram 208 230 1 60...
Page 102: ...102 APPENDIX D WIRING DIAGRAMS Fig P 50FC 04 07 Power Wiring Diagram 208 230 3 60...
Page 103: ...103 APPENDIX D WIRING DIAGRAMS Fig Q 50FC 04 07 Power Wiring Diagram 460 575 3 60...
Page 104: ...104 APPENDIX D WIRING DIAGRAMS Fig R 50FC 04 06 SystemVu Control Wiring Diagram All Voltages...
Page 105: ...105 APPENDIX D WIRING DIAGRAMS Fig S 50FC 07 SystemVu Control Wiring Diagram All Voltages...
Page 106: ...106 APPENDIX D WIRING DIAGRAMS Fig T 50FC 04 06 SystemVu Power Wiring Diagram 208 230 1 60...
Page 107: ...107 APPENDIX D WIRING DIAGRAMS Fig U 50FC 04 07 SystemVu Power Wiring Diagram 208 230 3 60...
Page 108: ...108 APPENDIX D WIRING DIAGRAMS Fig V 50FC 04 07 SystemVu Power Wiring Diagram 460 575 3 60...