Danfoss PVG 32 User manual

MAKING MODERN LIVING POSSIBLE
Service Manual
PVG 32
powersol ution s.danfoss.com
Property of American Airlines

r.4ffi i/ ,,
'j;ffi"
Service Manual PVG 32 Proportional Valve Group
System Troubleshootin g
Overview
A Warning
l-his troubleshooting guide for the PVG valve assemblies cjoes not cover valves that have been alterecj
from original valve build specifications
This section provldes generalsteps to follow if undesirable 5ystem conditions are observed. Followthe
5tep5listed untilthe problem is solved. Some of the items will be system specific. Always observe the
safety precautions listed in the /ntfoduct on sectlon, and related to your specific equipment.
Confirm thatvalve i5 built properly accordlng to the specification sheet.
lfnecessary installa lev€r to thevalvetoveri! proper mechantcal function.
Refer to PVG 32 Technical Information Manual52OtO344 for valve configuratlon information.
Refef to PVG 32 Parts Manual 11006794for part numbers.
Troubl€shooting a PVG Yalv€
THINK- before troubleshooting a problem.
Everyfault location process shouldfollow a logicaland systematlc order.
It is wisest to start at the beglnnlng:
. lsthe oil level correct when the pump is op€ratlng?
. ls the condition ofoiland filters acceptable?
. Are pressure. flow, and flow direction as 5pecifled?
. lsrhe oiltemperature too high ortoo low (oilviscosity)?
. Are thele any unusual vibratlons or noise (cavitatlon)?
lf the driver ofthe vehicle i5 available, ask him:
. What type of f"ult it is and how it affects the system?
. How long he has he felt that something has been wrong?
. lfhe has'fiddled" with the comDonents?
. lf he has any hydraulic and electrtcal diagrams available?
Diagrams areoften found in the instyuctions included with vehiclevmachines,
, Unfonunately they are often 50 technical that they are not of much use in a fault locatlon situation.
However the diagram usuallyshowsthe order of, and the connections between, the individual
components.
When a defective component is identified, clean the componentand its surroundings before removal.
Remove loose paintfrom pipes and fittings.
Coverallholes, hoses and pipe end5 with plugs or seal with, for example, plastic bags after removalto
avoid the entry of dirt durlng repairs.
Never disassemble hydraulic components outside,
Perform repairs in a workshop on a clean workbench (covered with clean cloth or newspaper).
. Make sure that a Danfoss service manualfor with the product is handy.
' Followthe instructions word for word during disassembly and assembly,
lfthese lnstructions are not followed closely the syster! may not operate correctly after repairs are
comDleted.
Notethat in some cases specialtools are neressary for assembling the product
14 | 1 0391 57 . Rev BA . May 201 4
Property of American Airlines

"#@
Service Manual PVG 32 Proportional Valve Group
System Troubleshootin g
Troub I eshooting flow cha rt
Our service manuals give full guidance on use of special tools.
No cylinderlmotor response in either direction when remote controller is actuated
P1 07 823
Mechanica
Ele:ctronic
Software
Cause Check Corrective action
Veriff if fault is mechanical, electrical
or hydraulic Operate manual lever to confirm mechanical or
electrical or hydraulic lf moving the manual lever operates the cylinder/motor
check electrical or hydraulic
Sticking main spool Remove manual, electrical, and hydraulic actuators
from the valve section. Remove main spool from valve
section and inspected for damage. lf no damage
reinstallthe main valve spool and it should move
freely in the valve section bore.
Replace the valve module and main spool. lf any damage
is found on the main spool
Check movement of manual lever when electrical
controller is operated lf manual lever does not move check electrical voltage
signal from controller, wiring at the PVE module
Check movement of manual lever when hydraulic
controller is operated lf manual lever does not move check hydraulic controller
pressure at the PVG valve module - 25 Bar t36O PSll
lf none of the above check pump per manufacturers
recommended procedure Repair or replace pump per manufacturers
recommended procedure
lnternal filters blocked Checkfor blockage in internalfilters rRemove blockage
17039167 . Rev BA . May 2o14
Property of American Airlines

Service Manual PVG 32 ProportionalValve Group
System Troubleshooti n g
Cylinder/motor responds in one direction only
Main valve spool moveswithout oil passing to cylinder/motor
Cause Check Corrective action
Veriff if fault is mechanical, electrical
or hydraulic Operate manuallever in both directions to confirm if
mechanical or electrical or hydraulic lf moving the manual lever operates the cylinder/motor
in both directions check electrical or hydraulic
lf operating the manual lever strokes the cylinder/
motor in one direction only, check manual stop screw
adjustment
Back out manual stop on manual controller and torque
the jam not to 8 Nm [70 lbf.in] Do not exceed maximum
torque
Check movement of manual lever when electrical
controller is operated lf manual lever does not move in one direction check
electricalsignalfrom controller and wiring at the pVE
module
Check movement of manual lever when hvdraulic
controller is operated lf manual lever does not move in both directions check
hydraulic pressure at the PVG module
Air in system Entrained air generates heat under pressure Lookforfoam or bubbles in reservoir. Checkfor leak on
inlet side of charge pump.
Internalleakage Excessive internal leakage may overheat the system. Install loop flushing defeat option and monitor case flow.
lf case flow is excessive, motor may require major repair.
Contact Danfoss Service.
Shock valves Swap and see if problem follows Replace valves
Solenoid actuation lf power is OK from controller Repairwiring to PVE module
Main spool travel restricted Stop on manual controller turned in too far Back out manual stop on manual controller
Remote electrical controller Insufficient signal from electrical controller Repair or replace electrical controller
PVEO connections Incorrect PVE/PVEO con nections Connect correct way
Remote hydraulic controller PVRH Insufficient pilot oil pressure from remote hydraulic
controller Pressure needs to be 25 Bar [360 psi] Repair or replace remote hydraulic controller
Cause Check Corrective action
Insufficient oil supplyto valve Checkthe pump per manufacturers procedure Repair or replace pump per manufacturers procedure
Optional pressure compensator in
valve section not functioning Check compensator spool Replace spool
Insufficient load pressure at
compensator spring chamber LS drilling holes plugged Clean or replace
Cylinder/motor load too high for
pressure setting of the system Check pressure at the valve lf pressure is set to spec. per valve lower load on cylinder/
motor
Blocked LS galleries Inspect for blockage in LS galleries Remove blockage in LS galleries
Shuttle valve faulty lnspect shuttle valve Repair or replace
Blocked LS lines to pump controller Inspect LS lines from PCG to pump controller Remove blockage in LS lines from the PVG valve to pump
controller
Oil bypassing at shock valve/antF
cavitation check valve Check if stuck open or damaged Replace valve
Internal leakage in cylinder/motor Inspect for by-passing of oil per cylinder/motor
manufacture per manufactures proced u re Repair or replace cylinder/motor per manufactures
procedure
Too much leakage in LS spool in pump
control Check bleed orifice in LS control Use a LS pump controlwith no bleed orifice
Blocked thermal orifice check thermal orifice (blocked) Replace thermal orifice
Load too high for system check for proper system pressure Adjust pressure to valve specification
lnternal leakage in cylinder/motor Inspect for bypassing of oil per rylinder/motor
manufacturer specification Repair or replace cylinder/motor
Shock valve or anti-cavitation check
valve faulty lnspect for damage and contamination Repalr or replace cylinder/motor
System relief valve pressure set too low
for load Install pressure gauge and check pressure Adjust pressure to system specification
Lower load
11039167. Rev BA . May 2O14
Property of American Airlines

:fuffi
Service Manual PVG 32 Proportional Valve Group
System Troubleshootin g
Cylinder/motor operates without remote controller being operated
Cylinder/motor responds slowly to remote electrical or hydraulic controller actuation
Erratic cylinder/motor response to electrical or hydraulic controller operation
Cause Check Corrective action
Cylinder/motor load too high for
pressure settings of system Check load pressure at PVB-LS port Reduce load pressure if exceeds maximum pressure limit
of the system
Maximum system pressure should be approx. 25
Bar [365 PSIJ above highest load pressure Adjust maximum system pressure if necessary
Adjust pump pressure compensator setting if
necessary
Cause Check Corrective action
Spool control tension rod loose Confirm torque on spoolcontroltension rod Torque to I Nm I70 lbf.inl
Electrical feedback transducer not in
neutral position Checkthe feedback pin in the PVE. lt should be loose Replace transducer
Remote electrical controller neutral
position switch faulty Disconnect the connection at the PVE. lt should come back to
neutral Repair or replace faulty switch orwiring at
remote controller
Sticking pressure control valve in remote
hydraulic controller Disconnect the hydraulic signal linefrom valve Repair or replace faulty remote hydraulic
controller
Sticking main spool in valve section Remove manual, electrical, and hydraulic actuators from the
valve section. Remove main spoolfrom valve section and
inspected for damage. lf no damage reinstallthe main valve
spool. Spool should move freely in the valve section bore.
Replace the valve module and main spool if
any damage is found on the main spool
Internal fault in the PVE/PVEH/PVEM/
PVEO PVEO check continuity. All other PVE, check LED (Fed means
internal error) Replace faulty PVE/PVEH/PVEM/PVEO
Contamination in the hydraulic oil Take oilsamples to confirm Flush hydraulic system. Fill with clean
filtered oil.
Cause Check Corrective action
Insuffi cient system pressure lnstall pressure gauge and record pressure lf pressure is low adjust pressure setting to valve
specification or pu m p manufacturers specification
Main spool travel limited Check stops on manual lever controller end for proper
adjustment.
Refer to Co m po nent trou bles h o oti n g section.
Adjust the manual lever stops and torque the jam nuts to
8 Nm [70lbf.in] Do notexceed maximum torque
lncorrect signal voltage from
electrical controller Checkthe signalvoltagefrom the controller with a
volt meter lf signal voltage is incorrect repair or replace electrical
controller
Incorrect hydraulic pressure signal
from remote hydraulic controller Check pressure from the remote hydraulic controller-
25 Bar t360 PSll lf pressure is too low, repair or replace remote hydraulic
controller per manufacturers instructions.
Insufficient pilot oil- all sections Check pilot for contamination and correctly
assembled parts - l0-15 bar [145-21S psi] Electric - Z5
bar [360 psi] Hydraulic
Replace inlet module NOTE: Check with S-D TST
Insufficient LS pump stand by
pressure Check pilot PSl - 1 0-'l 5 bar [145-21 I psi] Electric - 25
bar [360 psil Hydraulic Adjust or replace pump
Flow is not load independent PVLP check for cracks
Check L5 pressure vs load pressure Replacevalve
Cause Check Corrective action
Electrical actuator faulty Check signalfrom controller to PVE .Repair or replace PVE
Main spool centering spring
damaged Check tension rod for correct torque or damage Torque to I Nm [70lbf.in] or replace
1 1039167 . Rev BA . May 2A14
Property of American Airlines

Service Manual PVG 32 Proportional Valve Group
System Troubleshooting
Hydraulic oil supply
Electrical supply
Check for contamination per specification HPP O3O. Refer ta Design Guideline for Hydrautic Ftuid
Cleanliness,Technical Information Manual 52OLA467.lf fluid is out of spec., flush hydraulic system and fill
with clean filtered oil.
Cause Check Corrective action
Main spool position feedback
transducer signal incorrect Check feedback pin for damage Replace PVE
Contamination in hydraulic oil Take oil sample Flush complete system.
Fill reservoir with clean filtered fluid per OEM
specification
Air in hydraulic pilot lines Check for air trapped in signal lines from the
controllerto the valve section module Bleed air from the hose connection at the valve section
Hydraulic remote actuator faulty Check signal pressure from the remote hydraulic
controller Repair or replace cylinder/motor
Low hydraulic oil supply Check fluid level in reservoir Fill reservoir with clean filtered fluid per OEM
specification
Cause Check Corrective action
Pump not running Check prime mover for operation Repair or replace prime mover
Checkcondition of drive coupling Repair or replace drive coupling
Insufficient oil in reservoir Check fluid level in reservoir Fillwith clean filtered oil
Leaking or burst supply hose Inspect lines to valve stack Repair or replace damaged hose
Relief valve malfunction Checkfor contamination and operation of relief valve Repair or replace relief valve
lsolating valves are closed Check that all isolating valves are open and clear
Faulty pump control Check pump compensatorfor correct operation and
setting per pump manufacturers Repair or replace pump compensator per pump
manufacturers recommendations
Low standby pressure in PVP - open
center pump Check idle standby pressure - l0 Bar [145 psl] Replace
Check condition of compensator spool spring Replace module due to worn components
Low standby pressure in pump
control- variable pump Check pump LS control for operation and setting
Stand by pressure should be 15 bar [220 psil
minimum
Repair or replace LS control per pump manufacturers
procedures
PVP pressure relief valve faulty Check pressure relief valve spooland spring for
freedom of operation Replace
PVP orifices blocked Check PVP orifices for blockage Remove blockage
Internal fi lters blocked Check for blockage in internal filters Remove blockage
Supply lines blocked lnspect supply lines for blockages Remove blockage
lnternal hydraulic pilot pressure
insufficient Inspect pilot oil pressure reducing valve for proper
operation Repair or replace
Blocked LS galleries Check LS galleries for blockage Clean blockage from LS galleries
Shuttle valves faulty Check LS system shuttle valves for wear and damage Replace as needed
Cause Check Corrective action
No electrical power Check electrical circuit Repair as needed
Veriff emergency stop switch is in the proper operating position Reset
Neutral position switch faulty Check operation of neutral position switch in remote controller (if
connected in circuit) PVRE/PVRE5/PVREL 'Replace switch
11039167. Rev BA. Mav 2014
Property of American Airlines

'ffi@
Service Manual PVG 32 Proportional Valve Group
System Troubleshooting
Hydraulic (remote) pilot control pressure
Cause Check Corrective action
lncorrect signal voltage Check voltage levels at solenoid plug
Proportional operation - Refer to Troubleshooting Considerations
Udc: Supply voltage (1007o)
Us: Suppfy si gnal voltag e (25-50-7 5o/ol
Ground: Live or ground connection
On-Off Operation
Udc: 5upply voltage if selected
Us: Supply voltage if selected
Ground: Live or ground connection
Solenoid valve faulty PVHC Check coil resistance Check data for resistance
Insufficient pilot supply Check pilot pressure - 10-15 bar [145-218 psi]/PVHC 25 bar [360
psil Replace
Main spool position feedback
transducer signal incorrect Test oil for contamination and or water content lf oilcontamination is too high, flush hydraulic
system or replace oil if necessary. lf problem
persists change PVE
lncorrect PVE connections Check that the proportional remote electrical controller has not
been connected to an ON-OFF PVEO solenoid Connect wires correctly
Cause.,, Check Corrective action
Insufficient pilot pressure Check pilot oil pressure 5-15 bar t72-22O psil delta between A and
B port on remote
PVG32:5-15 Bar 172-217 PSll
Insufficient pilot oil supply Check pilot oilflow rate is adequate
Pilotflowshould be 1.0 L/min [0.264 GPM] persection
Check pilot lines for blockage Remove blockage
Air in pilot line Check for trapped air in pilot lines Bleed air from pilot lines at PVH
Pilot lines incorrectly sized Check pressure drop Check and reduce length or pilot lines
Increase diameter of pilot lines
Use steel tube for long pilot line runs
Hydraulic remote pilot operator
faulty Check operation of hydraulic remote pilot controller Repair or replace
Check supply pressure to hydraulic remote controller- minimum
25 bar [360 psi] Repair or replace
Check and inspect movement of pressure control valve in
hydraulic controller Repair per manufacturers procedure, or
replace
Check operaticin of remote hydraulic controller Clean and/or repair as necessary
1 I O39l 67 . Rev BA . May 201 4
Property of American Airlines

Service Manual PVG 32 Proportional Valve Group
PVG 32 Component Troubleshooting
Pressure relief valve
Description: Adjustable relief valve. Adjustment range 50 Bar [700 PSI] to 350 Bar [5000 PSI].
Location: The relief is in all PVP Inlet modules
Function: Provides maximum pressure setting above pump pressure setting 30 Bar t450 PSll Delta for
open center and closed inlet sections
Failure mode Cause Corrective action
Will not build pressure Contamination While under pressure, back out to minimum pressure and allow oil
to leak by for approx. 5 seconds and then readjust to correct
pressure - Replace valve
External leaking Damaged seat and poppet Replace complete assembly
Pressure setting is wrong Pressure adjustment backs off (on open
center application) Adjust to model code specification
Instability when PC and inlet relief
has too low of a delta between
them
PC at pump should be set 20 bar below relief
valve Adjust to model code specification
Serviceability: Non servicea ble.
Valve removal tool P/N: 155L6485. Torque to 20 Nm ['|80 lbf,in].
Pressure reducing pilot valve
Description: Pressure reducing valve at fixed pressure.
Location: The pressure reducing valve is a option in some pvp Inlet modules.
Function: Provides 10-15 bar il45-218 psil internal pressure for electrical (PVE) actuators or provide 25
Bar (360 PSI) (PVHC) and supply for external remote hydraulic actuators (HRC). These pressures are only
present when the load pressures are high enough to satisfy the required regulated pressure. The open
center system at low pump flow may only develop 9 Bar (130 pSl)
Failure mode Cause Corrective action
Main spools are slow, driven by
PVE 13 Bar [190 PSI] pilot system Contamination Disassemble and clean
Pump pressure too low - below 9 Bar [130 PSl] Closed center: System increase stand-by to I3 Bar Il90 PSII
Open center: Check gear per pump manufacture procedure
Check system for other components before valve inlet that may
provide a path tank
High tank port pressure. Do not exceed 40 Bar
t580 PSll tank pressure (For PVPs withoutT0
option)
Clear restrictions in return system.
Oilviscosity 460 mm2/5 t2128 5U5l too high
(cold oil or incorrect viscosity oil) Warm up system or replace oilwith correct viscosity
Main spools will not move
mechanically or electrical ForT0 option only not being connected to
tank or restricted to tank Connect T0 (PVP) port option to tank or remove restriction
Internal pressure reducing valve parts
misassembled Reassemble the internal pressure reducing valve parts correctly
1 1039167 . Rev BA. May 2014
Property of American Airlines

Eauid
Elark
WWW.DAVIDCLARK.COM
TNSTALLATION/OPERATION INSTRUCTIONS
U38OO MASTER STATION
DESCRIPTION
The U3800 Master Station is the heart of the David Clark Company Series 3800 Intercom
System. The 3800 adjusts automatically for 12 or 24 VDC power source. It contains system
on/off and volume controls, power input and a remote output, system fuse, plus 2 headset jacks.
INSTALLATION
1. Select a mounting location where the headset cord will not interfere with the operator's job
fonetion orotfiemrise foree actirms{rat may jeopae#.ze s*feoperation.
WARNING
Caution should be taken with the U3800 when selecting a mounting
position so that it's at least 2 feet away from the transmitter antenna.
2. Mount the U3800 by placing one grommet between each of the four mounting brackets and
the mounting surface. Grommets are provided with the module but fasteners are not. The
type of fastener selected should be based on mounting locafion.
3. A C3820 Power Cord, twenty feet in length, is required to connect a U3800 Master Station
to it's power source. The stripped and tinned end of the C3820 incorporates a fuse holder
with a 2 amp slo-blow fuse. If connecting to a vehicle's power source, consideration should
be given to whether you connect before or after the ignition switch. The red wire should be
connected to DC positive (power) and the black wire should be connected to DC negative
(ground). Connect the two pin (male) connector of the negative (ground). Connect the two
pin (male) connector of the power cord to the power input connector located on the Master
Station.
NOTE: It is recommended that a Noise Suppression Kit, such as
Radio Shack PAI 270-030 or equivalent, be installed on the
power line to the U3800 Master Station to help prevent
electrical noise from entering the intercom system. Install
the filter at the point where power is derived.
4. All cords have military type screw-on connectors. Install cords as follows:
Align key-way slot on cord connector with key in threaded connector on module.
Insert pins into socket until firmly seated.
Hand tighten swivel nut on cord connector.
5. Connect Master Station to Remote Modules using (C3B-XX) Jumper Cords of desired
length. &
a.
b.
c.
19s0sP-43 (10-ls) 1of 302015 David Clark Company Incorporated
Property of American Airlines

6 Plug headsets into headset jacks and ensure connectors are fully seated.
OPERATION
1. Push the white on/off button, it will illuminate, indicating power "on".
2. Turn the system volume control knob to approximately 1/3 turn from the off position.
3. Adjust headset for a comfortable fit. Position the boom mounted microphone directly in
front of your mouth, no more than 1/8 inch from your lips.
4. Speak into the microphone. If you hear yourself speaking through the earphone, you are
ready to communicate. If you do not hear yourself through the earphone, check the
microphone switch located on the earcup to be sure it is in the "on" position.
Above each headset jack on the Master Shtion and RemotJHeadset Station is a headset
volume control. Adjust your individual volume control to a comfortable listening level.
Should more volume be required, increase the system volume by turning the system volume
control knob clockwise.
NOTE: To prevent ambient noise from being fed into the system
during periods of no communication, press the microphone
switch on the headset to the off position.
With the microphone circuit turned off, the earphone circuit remains active for monitoring of
system.
19505P-43 (10-15) 2 af3
Property of American Airlines

SERIES 38OO SYSTEM TROUBLESHOOTING
CARE AND MAINTENANCE
. Headset and earseals can be cleaned with a damp cloth.
o Store components in a clean, dry area.
o Damaged components should be returned to the distributor or factory for service.
Failure Mode
No Communication
Possible Cause
U3800 Master Station not turned on.
Volume control turned off
(a) Remote Headset Station
(b) Master Station
Microphone switch on headset turned off.
M+ster S+atien-fuse-blswn.
Power cable line fuse blown.
DC power loss.
Squeal
o Headset plug not seated in headset jack.
o Headset on line, but not being worn, with push-to-
talk switch locked on. Microphone is probably too
close to open earphone, causing feedback.
Distortion . System and headset volume control set too high.
Intermittent
Communication o Loose connectors
Low Volume o Speaker's mic placement poor.
-c-System-volume"contrffi lume-contrslset -
too low.
19505P-43 (10-15) 3 of 3
Property of American Airlines

No. Description Part No.
1 Fuse 09486P-09
2 Fuse Holder 09487P-07
3 "O" Ring Washer (10/pk) 18900G-05
4 Knob 09347P-15
5 Shaft Seal Nut 13145P-05
6 Volume Control 09349P-30
7 Jack Cover (with Nut) 09518P-04
8 Neoprene Washer (10/pk) 18900G-39
I Headset Jack 09228P-03
10 Push Button Cap 13056P-1 1
PARTS LIST
MODEL U3BOO
No. Description Part No.
11 Lightbulb 09493P-01
12 On/Off Switch (with bulb) 09851P-21
13 Mounting Kit 09865P-03
14 Grommet (4 ea.) 18900G-08
15 Connector (4 socket) 00084M-04
16 Screws and Nuts (4 ea.) 18900G-01
17 Cap (and nylon cord) 13238P-01
18 Gasket 13176P-03
19 Connector (2 Pin) 00084M-03
2A . Box 26497P-Q3
Eauid
Elark
WWW, DAVI D C LA R K, CO M
@-14
HEADSET
JACK
(2)
VOLUME
CONTROL
,--& {3}
u--€
,-_--.g,
\f
,-@
MOUNTING.
KIT
t4l
8-@
N \l // zoN
@. 15
h
19512P-51 (10-15) @2015 David Clark Company lncorporated
Property of American Airlines

Dauid
'/ark
WWW.DAVIDCLARK.COM
INSTALLATION/OPERATION INSTRU CTIONS
U3801 REMOTE HEADSET STATION
DBSCRIPTION
The U3801 Remote Headset Station is used to expand a David Clark Company Series 3g00
Intercom System usually at the end of a series of headset stations. There are no output
connectors to connect additional modules. It has a jack to accept a plug from one headset and a
listen volume control.
INSTALLATION
--t ::-a:;1 a mounlttsFTiriffili"* trr" r,"uGi;"td;iil nor inrerfere *rh;h. "p";- j;
function or otherwise force actions that may jeopardize safe operation.
2' Mount the U3801 by placing one grommet between each of the four mounting brackets and
the mounting surface. Grommets are provided with the module while fasteners are not. The
type of fastener selected should be based on mounting location.
3' Connect a C3B-XX Jumper Cord, of desired length, from an output connector on the U3g00
Master Station or a Remote Headset Station to the "system'Input; connector on the U3g0l.
4' A11 cords have military type screw-on connectors. Install cords as follows:
a' Align key-way slot on cord connector with key in threaded connector on module.
b. Insert pins into socket until firmly seated.
c. Hand tighten swivel nut on cord connector.
5. Plug headset into headset jack and ensure connector is fully seated.
OPERATION
Adjust headset for a comfortable fit. Position the boom-mounted microphone directly in
front of your mouth, no more than 1/B inch from your lips.
Speak into the microphone. If you hear yourself speaking through the earphone, you are
ready to communicate. If you do not hear yourself through ifr" "utpnone, check that both the
master station and microphone switch located on the "ur.up are in the "ON" position.
NOTE: The earphone circuit remains active even if the microphone is
turned off.
3' Adjust the volume control on the U3801 for a comfortable listening level.
1.
2.
19s09P-16 (10-1s) 02015 David Clark Company Incorporated
Property of American Airlines

Eawd
Elark PARTS LIST MODEL U3BO1
WWW. DAVI.D C LA R.K. CO M
,,-*_C HEADSET VOLUME
No. Description Part No.
1 Knob AW47P-15
2 Shaft Seal Nut 13145P-05
3 Volume Control 09349P-30
4 Jack Cover (with Nut) 09518P-04
5 Neoprene Washer (10lpk) 18900G-39
6 Headset Jack 09228P-03
7 Connector (4 socket) 00084M-04
MOUNTING KIT
{4}
No. Description Part No.
8 Gasket 13176P-03
I Screws and Nuts (4 ea.) 18900G-01
10 Cap (and nylon cord) 13238P-01
11 Mounting Kit 09865P-03
12 Grommet (4 ea.) 18900G-08
13 . Box 26497P-A4
HEADSET.'ACK
INPUT/OUTPUT
1951 2P-52 (10-1 5) @2015 David Clark Company lncorporated
Property of American Airlines

ELECTRICAL SCHEMATIC
MODEL U3801
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