BENDIX BW2077 Manuale Utente

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FIGURE 2 - AD-IS
®
 AIR DRYER SYSTEM SCHEMATIC
charge cycle until the air brake system pressure builds 
to the governor cut-out setting of approximately 130 p.s.i.  
When air brake system pressure reaches the cut-out setting 
of the governor, the governor unloads the compressor 
and the electronic module sends a signal to one of the air 
dryers to purge.  The governor unloads the compressor by 
allowing air pressure to fi ll the line leading to the compressor 
unloader mechanism - causing the delivery of compressed 
air to the AD-IS
®
 EverFlow
 assembly to be suspended.  
Similarly, the governor also supplies air pressure to the 
EverFlow
™ 
electronic module. The electronic module uses 
this signal to determine the volume of air into the brake 
system. If the volume is normal, the electronic module 
sends a signal to the control port on the proper dryer. If the 
volume is high, the electronic module switches the dryers 
every 30 seconds until the air volume returns to normal.  
The air dryer purge piston moves down in response to a 
pneumatic signal from the EverFlow
™ 
electronic module, 
causing the purge valve to open to the atmosphere and 
Air then fl ows into the desiccant drying bed and becomes 
progressively drier as water vapor adheres to the desiccant 
material in a process known as “ADSORPTION.”  Dry air 
exits the desiccant cartridge through the delivery check 
valve and also through an orifi ce into the purge reservoir. 
The delivery check valve opens, supplying air to pressurize 
the air brake system.  The purge reservoir stores air that 
will be used to reactivate the desiccant during the purge 
cycle.  
The air dryer will remain in the charge cycle until the air 
brake system pressure builds to approximately 85 p.s.i.  At 
85 p.s.i. the EverFlow
 electronic module is actuated and 
begins the purge cycle.  When the air pressure reaches 
approximately 106 psi, the pressure protection valves 
will open and air will be supplied to the primary reservoir, 
secondary reservoir or other accessories.  If the pressure 
protection valves are preset to different values the valves 
will open in order of lowest setting to highest setting when 
charging a fl at system.  The air dryer will remain in the 
Note:
The AD-IS
®
 air dryer purge piston has a purge control channel 
drain. This allows any condensation in this area to fl ow  past 
a diaphragm in the top of the purge piston and out through a 
channel in the middle of the central bolt of the purge assembly 
to be drained.  During the purge cycle this drain is closed.
Bulk Tanker
Secondary
 Reservoir
Primary 
 Reservoir
CTI System
Pressure 
Protection Valve 
(Optional)
IN
CON
OUT
From 
Engine
CON
RES
CON
AD-IS
®
 EFM
Schrader 
Valve
CON
RES
CON
GOV
3/8"
1/2"
1/2"
1/4"
CON
Bulk Offl oad CTI
Dryer OUT
Check 
Valve
Supply 
IN
SEC
PRI
Supply 
IN
CON
Manual Valve
Accessories
Compressor
EverFlow
 Module
Governor
Compressor 
OUT
CON
EverFlow
IN
Discharge Line 
Unloader Valve