Carrier 07D - Manual (Page 29)

INSTALLATION
06D,07D
The control solenoids will be field wired to the
condensing unit control box (Fig. 16). All wiring
must comply with local codes. Figures 23 and 24 explain the operating sequence
of the 07DA210,112,215CapacityControlDevice.
WITH THE SOLENOID VALVE ENERGIZED
THE SOLENOID VALVE STEM WILL OPEN
THE GAS BYPASS PORT.
3. REFRIGERANT PRESSURE WILL BE BLED TO THE SUCTION
MANIFOLD THROUGH THE OPENED GAS BYPASS PORT. A RE­
DUCTION IN PRESSURE ON THE VALVE PISTON WILL TAKE
PLACE BECAUSE THE RATE OF BLEED THROUGH THE GAS BYPASS
PORT IS GREATER THAN THE RATE OF BLEED THROUGH THE
BLEED ORIFICE.
PRESSURE FROM THE DISCHARGE
MANIFOLD PASSES THROUGH THE
STRAINER AND BLEED ORIFICE
TO THE BACK OF THE PISTON
BYPASS VALVE. UNLESS BLED
AWAY, THIS PRESSURE WOULD
TEND TO CLOSE THE PISTON
AGAINST THE PISTON SPRING
PRESSURE.
DISCHARGE PRESSURE IN THE
DlSCHARGE MANIFOLD WlLL
CLOSE THE DISCHARGE PISTON
CHECK VALVE ISOLATING THE
COMPRESSOR DISCHARGE MANIFOLD
FROM THE INDIVIDUAL CYLINDER
BANK MANIFOLD.
-VALVE PLATE
WHEN THE PRESSURE BEHIND
THE PISTON HAS BEEN REDUCED
SUFFICIENTLY, THE VALVE
SPRING WILL FORCE THE VALVE
PISTON BACK. OPENING THE
GAS BYPASS FROM THE DIS­
CHARGE MANIFOLD TO THE
SUCTION MANIFOLD.
-CYLINDER DISCHARGE VALVE
THE UNLOADED CYLINDER BANK
WILL CONTINUE TO OPERATE
FULLY UNLOADED UNTIL THE
SOLENOID VALVE CONTROL DE­
VICE IS DE-ENERGIZED AND
THE GAS BYPASS PORT IS
CLOSED.
Fig. 23 - D7DA210,112,215 Compressor with Cylinder Head Unloading - Cylinder Bank Unloaded
2. WITH THE SOLENOID VALVE DE­
ENERGIZED THE SOLENOID VALVE
STEM WILL CLOSE THE GAS
BYPASS PORT
1. DISCHARGE PRESSURE
BLEEDS FROM THE DIS­
CHARGE MANIFOLD THROUGH
THE STRAINER AND BLEED
ORIFICE TO THE SOLENOID
VALVE STEM CHAMBER AND
THE BACK OF THE PISTON
BYPASS VALVE.
3. REFRIGERANT PRESSURE WILL
OVERCOME THE BYPASS VALVE
SPRING TENSION AND FORCE THE
PISTON FORWARD CLOSING THE
GAS BYPASS FROM THE DISCHARGE
MANIFOLD TO THE SUCTION
MANIFOLD.
CYLINDER DISCHARGE VALVE
Dl SCHARGE
VALVE MANIFOLD
h . CYLINDER DISCHARGE PRES­
SURE WILL FORCE OPEN THE
DISCHARGE PISTON CHECK
VALVE ASSEMBLY. REFRIG­
ERANT GAS WlLL PASS INTO
THE COMPRESSOR DISCHARGE
MANIFOLD.
-VALVE PLATE
.CYLINDER SUCTION
VALVE
5. THE LOADED CYLINDER
BANK WILL CONTINUE TO
OPERATE FULLY LOADED
UNTIL THE SOLENOID
VALVE CONTROL DEVICE
IS ENERGIZED AND THE
GAS BYPASS PORT IS
OPENED,
Fig. 24 - 07DA210,! 12,215 Compressor with Cylinder Head Unloading - Cylinder Bank Loaded
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