Danfoss MCV105C User manual

DESCRIPTION
The MCV105C Electrical Displacement Control (EDC) is a
two-stage electrohydraulic pump stroke control which uses
mechanical feedback to establish closed loop control of the
swashplate angle of Danfoss 46 cc Medium Duty
Pumps.
ThefirststageisaMCV116Atorque-motoractuated,double-
nozzle flapper valve that produces a differential output
pressure proportional to the applied electrical signal. The
second stage uses the differential pressure to drive its
double spool arrangement and port oil to the pump servo
pistons. The second-stage rotary spool configuration allows
a null deadband (for machine safety) in the pump’s output
while maintaining optimum dynamic response to control
commands.
• Single command source can be used to control both
hydrostatic pump and motor.
•Servo control deadband independent of signal null
deadband: offers safety combined with accurate and
responsive control.
• Resistance to the environment: silicone oil filled torque
motor prevents moisture condensation, environmentally
sealed first/second stage interface, full environmental
testing.
• Minimum long term null shift.
• Pilot supply screens in series. Upstream screen is
externally serviceable.
• Plugged first stage orifice will not drive pump towards full
stroke.
• First and second stages can be individually replaced in
the field.
• Single or dual coil torque motor.
FEATURES
The standard EDC is a single coil (one input to the torque
motor) Packard connector device. The first option is a dual
coil, which allows two command sources to be compared at
thetorquemotor,theresultingsignalbeingthealgebraicsum
between the two. Connectors are the second connector
option available. Dual pilot coils are available with both
connector types. See Wiring, page 8.
All MCV105C orifices will be provided through
Danfoss, Ames, Iowa.
Order the EDC either factory installed on pumps or as an
individual control.
Order replacement parts through Danfoss,
Minneapolis, MN. See Table C and D - Service Parts , page
3 to 4, for item number, part number and description
correspondence.
MCV105C directly replaces MCV105B. The MCV105C
housing is designed to firmly maintain the O-rings while
mounting. All MCV105C models are factory shipped with O-
rings installed, while the MCV105Bs were not. See Table C
ORDERING INFORMATION
TABLE A - INFORMATION NECESSARY TO SPECIFY
THE EDC.
PILOT STYLE DESCRIPTION
Single coil, 23 ohm,
22 Packard Weather Pack connector
Dual coil,
23 Packard Weather Pack connector
Single coil, 23 ohm
26 MS connector
Dual coil, 23 ohm
27 MS connector
Single coil, 643 ohm,
46 Packard Weather Pack connector
MCV105C 3 0 XX
STANDARD EDC CASTING
PILOT STYLE
- Service Parts, page 3, for the appropriate installation kit if
required.
MCV105C
Electrical Displacement Control - MDT
© Danfoss, 2014-05 11152452 • Rev AA • May 2014 1

TECHNICAL DATA
ELECTRICAL
THRESHOLD
6.25 ± 0.75 mA (single coil, 643 ohm)
16 ± 3.5 mA (single coil, 23 ohm)
23 ± 4.6 mA (using one of the dual coils)
11.5 ± 2 mA (using the dual coils in series)
23 ± 4 mA (using the dual coils in parallel)
DEADBAND
12.5 ± 1.5 mA (single coil, 643 ohm)
32 ± 7 mA (single coil, 23 ohm)
46 ± 9 mA (using one of the dual coils)
23 ± 4 mA (using the dual coils in series)
46 ± 9 mA (using the dual coils in parallel)
FULL STROKE CURRENT
18 ± 1.5 mA (single coil, 643 ohm)
90 ± 12 mA (single coil, 23 ohm)
130 ± 18 mA (using one of the dual coils)
65 ± 9 mA (using the dual coils in series)
130 ± 18 mA (using the dual coils in parallel)
For sizing drive sources, use 100 mA in computations
for single coil EDCs. See Input Current vs. Pump
Swashplate Angle, page 3.
COIL RESISTANCE @ 24° C (76 ° F)
23 ohms (single coil, optional)
643 ohms (single coil)
20 ohms (A, B terminals) (dual coil)
16.5 ohms (C, D terminals) (dual coil)
COIL RESISTANCE @ 104° C (220° F)
29 ohms (single coil)
842 ohms (single coil)
24.7 ohms (A, B terminals),
19.7 ohms (C, D terminals) (dual coil)
SUGGESTED DRIVE VOLTAGES
The MCV105A EDC uses a pilot valve that is current-
driven.Sincecoilresistanceisafunctionoftemperature,
as the pilot’s coil temperature increases, a higher input
voltage is required to drive the pilot to full stroke. Table
B - Suggested Voltage Drives, below, demonstrates this
relationship and lists the suggested voltage drives for
two coil temperatures.
MAXIMUM CONTINUOUS VOLTAGE THAT WILL NOT
DAMAGE THE DEVICE
6.0 Vdc @ 200 ° F (93.3° C) (dual coil)
7.5 Vdc @ 200 ° F (93.3° C) (single coil, 23 ohm)
30 Vdc @ 200° F (93.3° C) (single coil, 643 ohm)
COIL INDUCTANCE
0.085 Henries (single coil, 23 ohm)
0.062 Henries (A, B terminals 20 ohm) (dual coil)
0.047 Henries (C, D terminals 16.5 ohm) (dual coil)
2.372 Henries (single coil, 643 ohm)
HYDRAULIC
OIL VISCOSITY
40 - 6000 SSU
FLUID
Automatic transmission fluid or hydraulic oil, such as
Mobil DTE 24 or equivalent. Fluid cleanliness is ISO
4406 code 18/15 or better.
FLUID TEMPERATURE
The valve will be functional and undamaged at oil
temperatures of -40 ° to 121° C (-40° to 250 ° F). The
valve will meet performance specifications with a fluid
temperature of 21° to 82° C (70° to 180° F).
FILTRATION
The system hydraulics will have a filtration rating of ß 10
= 2 or better
TABLE B - SUGGESTED VOLTAGE DRIVES.
120°F (49 °C) OIL TEMPERATURE 180°F (82°C) OIL TEMPERATURE
COIL CURRENT (mA) VOLTAGE (Vdc) CURRENT (mA) VOLTAGE (Vdc)
SINGLE (23 ohm) 90 2.2 90 2.5
SINGLE (643 ohm) 18 13.2 18 14.7
DUAL (Coil A) (A, B terminals) 132 2.7 132 3.0
DUAL (Coil B) (C, D terminals) 132 2.2 132 2.5
DUAL (In Series) 66 * 2.4 66 * 2.6
DUAL (In Parallel) 132 * 1.2 132 * 1.3
* Algebraic sum of currents in the two coils.
© Danfoss, 2014-05 11152452 • Rev AA • May 2014 2

11 5
8 9
2 3
10
6
12
7
1
DO NOT REMOVE
COVER SCREWS (4)
13
14
4
INPUT CURRENT VS. PUMP SWASHPLATE ANGLE
Input current vs. pump swashplate angle. Pump RPM is 1750 and the output load is 650 psi. Left curve is a dual coil
EDC and right is a single coil.
1351
17°
15°
10°
5°
0°
-100
mA
-50
mA
0+50
mA
+100
mA
PUMP OUTPUT FLOW
90% OF OUTPUT
PUMP OUTPUT FLOW
90% OF
OUTPUT
MAX. & MIN.
OUTPUT
PUMP RPM 1750
LOAD 650 PSI ±10%
HYD. OIL 110 ±10° F
MAX. & MIN.
OUTPUT
PUMP RPM 1750
LOAD 650 PSI ±10%
TEMP. OIL 110 ±10 ° F
17°
15°
10°
5°
0°
-100
mA
-50
mA
0+50
mA
+100
mA
SERVICE PARTS
1358H
NOTE: The cover is filled with a silicone oil. In the event this oil is lost, it is recommended it be restored. The
silicone oil is ordered under part number K21436, which includes instructions.
ITEMPART
1MCV116A3102 1 PILOT STYLE 22
1MCV116A3204 1 PILOT STYLE 23
1MCV116A3101 1 PILOT STYLE 26
1MCV116A3201 1 PILOT STYLE 27
1MCV116A3501 1 PILOT STYLE 46
2 K13340 1 LINK COVER
3 K13341 1 COVER GASKET
49004101-1190 1 O-RING (.93 I.D. X .103)
5 K07057 2 SOC HD CAP SCREW (1/4-20 X 5/8)
6 K11615 1 HEX SEAL NUT (5/16 - 24)
7 K04064 4 SOC HD CAP SCREW (10 - 32 X 5/8)
8 K08131 1 NULL ADJUST GASKET
9 K00944 1 NULL ADJUST COVER
10 K04167 4 SOC HD CAP SCREW (10 - 32 X .5)
11 K22582 1 FILTER KIT
12 K10057 1 SOC SET SCREW 5/16 - 24 X 1.1
13 K07006 2 O-RING (.49 I.D. X .07)
14 K22539 1 SLEEVE WITH SNAP RING
** KK05602 1 MOUNTING HARDWARE BAG ASSY
***KK05601 1 MOUNTING HARDWARE BAG ASSY
** BAG ASSEMBLY INCLUDES ITEMS 4 AND 13 AND MOUNTING SCREWS
*** BAG ASSEMBLY FOR MCV105B MODELS
TABLE C - SERVICE PARTS.
© Danfoss, 2014-05 11152452 • Rev AA • May 2014 3
NUMBER NUMBER QTY DESCRIPTION

10
9
8
7
6
5
4
3
2
1
11 12
13
14
15
16
16
17 18 19
SERVICE PARTS
(continued)
TABLE D - SERVICE PARTS.
3001
ITEMP/NQTYDESCRIPTION
1 K01291 5 SAE-6 Plugs
2K07067 4 PCP Mounting Screws
3 K00860 1 PCP Cover Gasket
4K02264 4 PCP Cover Screws
5K00920 1 PCP Null Access Screw
6 K11423 1 PCP Cover
7 K21436 1 Silicone Oil Kit 4000 cs
8K04196 1 Connector Gasket
9K08687 4 Connector Screw for MS
10 K01314 1 Connector MS
11 K08688 4 Connector Screw for Packard
12 K08106 1 Mating Electrical Connector MS
13 K08014 1 Feed Through Assy Cover Plate
14 K07533 1 Feed Through Assy
4-pin Packard W-P
15 K03384 1 Mating Electrical Packard W-P
16 K00829 2 O-ring control port
17 K00830 1 O-ring return port
18 K08573 1 Filter Assy with O-rings
19 K08493 1 O-ring pressure port
© Danfoss, 2014-05 11152452 • Rev AA • May 2014 4

Items referenced in Table D - Service Parts, page 4.
(1) Item 4.
(2) Items 4, 6, 8, 9, 10, 11, 13, 14. The following steps are
recommended when servicing those service parts listed
in Table D - Service Parts, page 4.
Preferred service tools are:
• Screw driver TX 15 and TX 10
• Solder SN62
• Needle nose pliers, small tip
• Solder iron, electronic type
• Volt/ohm meter (VOM)
• Cleaning solvent, Chemtronics 2000 ES 1601
• Torque wrench, 0-50 in•lb (0-66 N•m)
REPLACING COVER AND/OR
ELECTRICAL CONNECTOR
1. Wipe down external surface to ensure that loose
contaminants will not fall inside the housing.
2. Place the valveina firm positionat45° withtheelectrical
connectortiltedupwards(PCPsbuiltafter1988arefilled
withasiliconoil). Locateand remove the four connector
screws (Item 9 if MS connector, or Item 11 if Packard
connector).
3. Holdtheelectricalconnectoranduntwistwiresbyrotating
the connector CCW two turns while gently pulling away
from the housing.
4. Clean the solder connections inside connection of the
electricalconnectorwithdegreaser. Unsolderthewires,
noting which pin goes to which wire color (i.e., Pin A to
black, Pin B to red, Pin C to brown, etc.). With the
connector held firmly, place the solder iron against the
base solder cup if MS, and pin if Packard, until the wires
can be gently pulled away.
5. Thecovercannowberemovedandreplacedif required.
Besurethecovergasket(Item 3)isfirmlyseatedintothe
cover base and is in good condition before cover is
installed. Torque cover screws to 12-15 in•lb (16-20
N•m).
6. Verify that wire to pin connections are correct before
soldering wires. Also ensure that the connector gasket
(see Table D - Service Parts, Item 3, page 4) is in place
before soldering.
7a. For the MS style connector, ensure that the cups have
sufficient solder (approximately level). If additional
solder is required, place solder iron against the base of
the cup and add solder. While solder is still liquid, place
wire in the cup, remove iron and let cool for several
seconds while holding wire firmly.
SERVICE PARTS
(continued)
DO NOT Remove Cover Screws, unless replacing cover.
WARNING
7b. For the Packard style connector, the wire should extend
aroundandcontact the terminal post for at least 180° (1/
2 wrap to a maximum of 270°). When ready to solder,
heat the terminal and add solder, remove iron, and let
cool for several seconds while holding wire firmly.
8. After soldering, ensure that terminals and wires do not
contact one another.
9. If silicone oil is to be added, do so at this step with the
connector not yet attached to cover. Tilt cover upward
and add 45-cc of oil from container. The container (P/N
K21436) holds enough for 3 fills.
10. Before attaching the connector to the cover, rotate
connector CW two turns. This will bundle the wires
together, finishing with the notch up when viewed from
the outward side of the MS connector, and lead wires
down for Packard connector (see MS Connector Pin
Orientation, page 9). Insert connector screws and
torque to 8-10 in•lb (11-13 N•m).
11. With a VOM, check for proper coil resistance between
terminals A and B, and between C and D if PCP is a dual
coil.
© Danfoss, 2014-05 11152452 • Rev AA • May 2014 5

215,9
(8.5)
MAX.
134,6
(5.3)
MAX.
41,40
(1.63)
NULL ADJUST *
MOUNTINGHOLES
ROTARY VALVE
MANUALOPERATOR
40,13
(1.58)111,8
(4.4)
63,5
(2.50)
MAX.
50,8 (2.0)
NOMINAL66,80
(2.63)
ROTARY VALVE
BYPASS VALVE FULL OPEN AT (2) REVOLUTIONS
7–10 LB. FT CLOSING TORQUE .62±01 DIA. HEAD
WITH (2) .266 + .007 DIA. HOLES -.002
DRILLED THROUGH 90° APART
.5625–18 SAE STR THD O-RING BOSS
SYSTEM PRESSURE GAUGE PORT "A"
.5625–18 SAE STR
THDO-RING BOSS
CHARGE PRESSURE
GAUGEPORT
.5625–18 SAE STR THD O-RING BOSS
SYSTEM PRESSURE GAUGE PORT "B"
273,05
(10.75)
9,65
(0.38)
72,64
(2.86)101,60
(4.0)
78,23
(3.08)
79,76
(3.14)
*CAUTION: DO NOT ADJUST NULL ON PILOT STAGE.
USE SECOND STAGE NULL ADJUST.
DIMENSIONS
Dimensions of the MCV105C EDC in millimeters (inches).
1353D
© Danfoss, 2014-05 11152452 • Rev AA • May 2014 6

THEORY OF OPERATION
The MCV105C Electric Displacement Control (EDC) is a
two-stage electrohydraulic pump stroke control which uses
mechanical feedback to establish closed loop control of the
swashplate angle of Danfoss Medium Duty
Pumps.
The first stage, the MCV116A Pressure Control Pilot, is a
torque motor actuated, double-nozzle flapper valve that
produces a differential output pressure proportional to the
applied electrical signal. The second stage uses the differ-
entialpressureto drive a linear motion piston which actuates
a rotary spool through a cam and ports oil to the pump servo
piston. The second stage spool configuration allows a null
deadband (for machine safety) in the pump’s output while
maintainingoptimumdynamicresponsetocontrolcommands.
A command source such as a control handle or electronic
controller applies a dc current signal to the pilot stage of the
MCV105C Electric Displacement Control. The input current
commands the pilot’s torque motor stage, a bridge network
consisting of an armature mounted on a torsion pivot and
suspendedin the airgapof amagneticfield. Two permanent
magnets polarized in parallel and a connecting plate form a
frame for the magnetic bridge. At null the armature is
centeredintheairgapbetweenthemagnet’s opposingpoles
by the equivalence of their magnetic forces and the null
adjust centering springs. As input current rises, the end of
thearmature becomes biased either north or south, depend-
ing on the direction of the current. The resulting armature
movement is determined by the amperage of control current
and the differential pressure feedback forces.
The magnetic bridge output, flapper torque, in turn controls
the hydraulic bridge ratio. At null, the flapper is centered
between two nozzles. Upstream from each nozzle is an
orifice which provides a nominal pressure drop when the
system is at null. Between the nozzle and the orifice on each
side is a control port. As the torque motor shifts the flapper
away from one nozzle toward the other, a differential control
pressure results, the high side being the one nearer the
flapper. Fluid pressure rises on this side and moves the
flapper back towards null. When the torque output from the
motor equals the torque output from the pressure feedback,
the pilot system is in equilibrium. It is this pressure feedback
that makes the pilot a stand-alone closed loop pressure
control valve.
The second stage of the EDC uses a piston and rotary valve
arrangement that serves to separate the null deadband from
the feedback, giving both safety against null drift and quick
dynamic response to command changes.
The second stage’s null adjust is set with the modulating
spring compressed to the equivalent of 12 psi, which is the
amountof differential pressure required to move the actuator
spool one direction or the other. This is a factory setting that
defines the width of the actuator spool deadband and cannot
bechanged. By tighteningorloosening thenulladjust screw,
the fixed deadband is moved toward or away from the “A”
control port.
As differential control pressure (C1 - C2) rises beyond the 12
psi deadband, the actuator piston moves in one direction or
theother,pivotingacamwhichturnsarotaryvalve. Whenthe
valve turns far enough, oil is ported to the pump servo piston,
causing rotation of the swashplate in one direction or the
other. As the swashplate turns, an attached valve sleeve,
concentric with the rotary valve, turns and closes off the oil
being ported to the servo piston. Thus the swashplate angle
is forced to follow the angular input of the rotary valve.
PERFORMANCE
RATED CASE PRESSURE
40 psi operating pressure
MAXIMUM HYSTERESIS
3 mA (single coil, 643 ohm)
15 mA (single coil, 23 ohm)
18 mA dual coil
SYMMETRY
Input current required to reach rated output in each
direction must be equal within 10%.
LINEARITY
10% maximum of swashplate angle change between
anytwopointsexceptwithin5%ofthethresholdcurrent.
NEUTRAL LEAKAGE
0.65 gpm maximum at 200 psi across the valve with oil
of 145 - 160 SUS at 38° C (100 ° F).
POLARITY
A positive voltage applied to terminal B (single coil) or
terminals B or D (dual coil) will cause a pressure rise at
the C2 port.
NOMINAL FREQUENCY RESPONSE
90° phase lag and negative 6db amplitude ratio at
greater than 1.5 Hz (defined without orifices in A and B
ports and a charge pressure of 300 psi. The average
currentinput is 40mAwith asinewave inputof ±15 mA.)
See the Amplitude and Phase Response Curves.
STEP RESPONSE (Null to 63% full stroke)
The response to a current step input of plus or minus 85
mAwill resultinapumpstroke responsetimeof 0.5 ±0.1
second to 63% of full stroke.
STEP RESPONSE (full to full), maximum
The response from full forward stroke to full reverse
stroke varies per orifice size:
Orifice Size In InchesResponse In Seconds
(± .9 seconds)
No Orifice 1.2
0.0372.7
0.0471.7
0.0551.3
0.0640.9
© Danfoss, 2014-05 11152452 • Rev AA • May 2014 7

PERFORMANCE (continued)
SENSITIVITY
The valve will respond to a 2% change in input current
throughout the rated current range except for the
deadband region.
PULSE WIDTH MODULATION
When using a pulse width modulated current input, do
not exceed 110 mA for single coil devices or 150 mA
(algebraically summing the currents in coil A and B) for
dual coil devices. Avoid pulse width modulated frequen-
ciesbetween300and500Hz,whichapproachthepilot’s
resonant frequency of 400 Hz.
AMPLITUDE AND PHASE RESPONSE
Amplitude and phase response of the MCV105C tested
over the given frequency range with supply pressure of
225 psi. Amplitude response curve is on top; phase lag
is on bottom. The amplitude at low frequency is 40
±15
mA and the load is 650 psi. Frequency response varies
with the applied load. Curves are shown with a current
driver.
1352
ENVIRONMENTAL
SHOCK
50 G’s for 11 milliseconds. Three shocks in both
directions of the three mutually perpendicular axes for a
total of 18 shocks.
VIBRATION
Withstands a vibration test designed for mobile equip-
ment control consisting of two parts:
1. Cyclingfrom5to2000Hzin each of the three axes.
2. Resonance dwell for one million cycles for each
resonance point in each of the three axes.
Subjecttoacceleration levels of 1gto46 G’s. Accelera-
tion level varies with frequency.
HUMIDITY
After being placed in a controlled atmosphere of 95%
humidity at 49 ° C (120° F) for 10 days, the EDC will
perform within specification limits.
WIRING
Two wiring styles are available: MS and Packard connec-
tors. The MS connector has four pins, only two of which are
used (A and B) for single coil devices. (Note: device MS
connector is not field-replaceable.) Its mate is part number
K08106 bag assembly (MS3106E-14S-2S). See MS Con-
nectorPin Orientation, page9, forproper pinlocations. With
both designs, phasing is such that a positive voltage on the
Red wire (Pin B) will cause a pressure rise at the C2 port for
single coil valves.
The mating Packard connector is part number K03383 bag
assembly comprised of:
1. 2 (or 4) 14-16 gauge sleeves
2. 2 (or 4) 18-20 gauge sleeves
3. 1 plastic housing
4. 2 (or 4) gray cable seals
5. 2 (or 4) green cable seals
6. 2 (or 4) blue cable seals
See Ordering Information, page 1.
Toassemble thefemaletower connector,usethe follow-
ing directions:
1. Isolate the wires that extend from the command source
to the EDC.
2. Strip back the insulation 5.5 millimeters on both sides.
3. Push a ribbed cable seal over each of the wires with the
smaller-diameter shoulder of the seals toward the wire
tip. Select the pair of seals that fits tightly over the wires.
Thedistance fromthe tipofthewiresof thefirst (nearest)
rib should be 9.5 millimeters. Thus the insulation should
just protrude beyond the seal.
4. Select the larger of the two sets of pins, as measured at
Dimension A. See Dimension A diagram, page 9, if
using 14-16 gauge wire. Choose the smaller if using 18-
20 gauge. Place the wire into the socket so that the seal
edge is pushed through and extends slightly beyond the
circulartabs thathold itin place. SeePackardconnector
Crimp, page 9, crimp in the locations shown with a
Packard 12014254 crimp tool.
5. Manually insert the assembled wires into the back end
(large hole) of the plastic housing. Push until the wire
detents with an audible click, then pull back slightly to
0 db
-3 db
-6 db
-9 db
-60°
-120°
-180°
10Hz 20Hz
10Hz 20Hz
1 Hz
1 Hz
© Danfoss, 2014-05 11152452 • Rev AA • May 2014 8

DIMENSION A
WIRING
(continued)
MS CONNECTOR PIN ORIENTATION
Pin orientation of the optional MS Connector.
1276
D
C
A
B
DIMENSION A
Dimension A for selecting correct terminal.
1123
PACKARD CONNECTOR CRIMP PACKARD CONNECTOR PARTS
1077A 1078A
Crimp location and distance from tang to third rib of
Packard Weather-Pack Connector.
Packard Weather-Pack interlocked connector halves
with parts identified. Two wire connector shown.
CABLE
SEALS
SIDE "B"
RED
BLACK
SHROUD
CONNECTOR
SIDE "A"
DOUBLE-PLUG SEAL
TOWER CONNECTOR
MOUNTING
Danfoss
Danfoss
If there isamanual control mountedonthe pump, it must
be removed before the MCV105B is mounted. To do so:
© Danfoss, 2014-05 11152452 • Rev AA • May 2014 9

MOUNTING
2. Removetheboltunderthehandle ofthe manualcontrol.
Lift off the handle, rotary spool and spring and bracket
assembly. Useavisegriptopulltheoldsleeveoutofthe
pump. Remove the two pipe plugs from the pressure
andreturnports. Removetheinletorificeinthepressure
port.
If there is no manual control:
1. The EDC is shipped with an attached spool and sleeve
assembly. Remove the sleeve from the valve. With the
notch in the sleeve facing down and toward the pump
shaft, place the sleeve in the pump valve bore until the
attachedsnap ring bottoms out. See Sleeve Placement
On Pump, below.
2. If there are caps over the pump’s pressure and return
ports, take them off.
3. Ensure O-rings are in place. See EDC O-Ring Place-
ment, below.
4. With extreme caution, guide the EDC spool into the
sleeve in the pump until the EDC’s four bolt holes are
properly aligned to the pump mounting holes. There is
only one possible alignment.
Note: Any damage or nicks to the spool while installing
could cause control to bind and produce erratic results.
5. Putthe2shortscrews(1/4-20x3/4")through thebosses
on the side of the valve. Put the two long screws (1/4-20
x 2.5") through the valve body. See Dimensions, page
6.Torque the fourscrews,in acrosspattern startingwith
the bolt closest to the pilot, to 10-11 ft. lbs.
Note: Improper torqueing may cause control to bind and
produce erratic results.
6. If needed, install control orifices under both servo
covers.
SLEEVE PLACEMENT ON PUMP EDC O-RING PLACEMENT
1355A
Sleeve placement on the pump. Electrical Displacement Control o-ring placement.
1356A
PUMP NEUTRAL ADJUSTMENT
Usethefollowingproceduretobringthepumptoneutral
once the Electrical Displacement Control has been
mounted.
1. Installa300 psi gauge in eachservopressuregauge port
on the pump. See Location, Servo Gauge Port, page 11.
2. Using a 9/16-inch wrench, loosen the hex lock nut on the
null adjustment screw. See Dimensions, page 6.
WARNING
To adjust neutral requires operating the pump. Take the
necessary safety precautions such as having unneces-
sarypersonnelstand awayfromthemachine. Maximum
system pressure may occur upon start up, and the
machine may move. Ensure that the operator is not in a
position to be injured should the machine move.
© Danfoss, 2014-05 11152452 • Rev AA • May 2014 10

3. Disconnect the electrical line at the connector.
4. Start the prime mover and run at low idle.
5. Warm the system up for several minutes to bleed air.
6. Slowly increase the prime mover speed to rated rpm.
7. Slowly rotate the neutral adjustment screw, with a 5/32"
Allen wrench, until the pressure is equal in both servo
gauges.
8. Slowly rotate the neutral adjust screw until one of the
servo gauges starts to increase in pressure.
9. Slowly rotate the neutral adjust screw in the opposite
directionuntilthe other servo gauge beginstoincreasein
PUMP NEUTRAL ADJUSTMENT
(continued)
pressure. Note the amount the neutral adjust screw was
turned in this step.
10. Turn the neutral adjust screw back one half the amount
turned in Step 9.
11. Hold the neutral adjust screw and torque the lock nut to
25-30 in.-lbs.
12. Stop the prime mover.
13. Reconnect the electrical line.
14. Run the system briefly to ensure that it operates propor-
tionally on both sides of the null command. Swashplate
movement can be verified by watching movement of the
swashplate feedback shaft, see Dimensions, page 6.
LOCATION, SERVO GAUGE PORT THROUBLESHOOTING
The MCV105C EDC is one component in a control system.
Whenthesystemfails,checkthemostobviousfailuremodes
first. Is the battery fully charged? Is there a hydraulic leak
somewhere? Are all connections tightly fastened? Are O-
rings in place?
When a process of elimination indicates that the system
problem may reside in the EDC, the failure mode is likely to
be one of the following six.
1357
Location of one of the servo gauge ports on the pump.
WARNING
Electrical actuation of the valve and/or hydraulic jogging
of the valve may cause pump output and movement by
the driven machine. Take precautions to ensure that no
personnel are in a position to be injured by the machine
if it should move.
TROUBLESHOOTING FAILURE MODES
A. NO PUMP OUTPUT
1. Check voltage or current supply to the pilot stage.
If faulty, check the electrical system. If fine:
2. Check the coil resistance in the pilot at the input
connector to the pilot. The resistance across the
twoPins (A andB)should be23ohms forsinglecoil
pilots. For dual coil pilots, resistance is 20 ohms
across A and B and 16.5 ohms across C and D. If
resistance is infinite across either coil, the pilot
should be replaced.
3. Jogthemanualoperatoronthetopofthepilot. Ifthe
hydraulic system does respond, the failure must be
anelectricalproblem. Ifthereisnoresponse,check
the service filter in the casting for the possibility of
damage or plugging. See Dimensions, page 6. If
the filter is dirty, replace it. If it is clean, replace the
pilot.
B. THE PUMP CANNOT BE NULLED OR CREEPS
SLOWLY IN ONE DIRECTION
1. Replace the pilot with a spare. If the problem is
solved, the pilot is faulty. If the problem is not
solved, unbolt the second stage from the pump and
check the spool and sleeve for contamination or
damage. If cleaning these parts clears up the
problem there is a filtration problem. Check the
charge pump filter and change pump oil.
.4375–20 SAE STR
THR O-RING BOSS
SERVO PRESSURE
GAUGE PORT
(2) PLACES
© Danfoss, 2014-05 11152452 • Rev AA • May 2014 11

IN EUROPE ORDER FROM
Danfoss (Neumünster) GmbH & Co.
Order Entry Department
Krokamp 35
Postfach 2460
D-24531 Neumünster
Germany
Phone: [phone]
Fax: [phone]
TROUBLESHOOTING FAILURE MODES
(continued)
C. THE PUMP RETURNS SLOWLY OR NOT AT ALL TO
NEUTRAL
1. Check charge pump pressure. If sufficient:
2. Unbolt the second stage from the pump and check
the spool and sleeve for contamination or damage.
If cleaning these parts clears up the problem there
isafiltrationproblem. Check the charge pump filter
and change pump oil.
D. PUMP OPERATES IN ONE DIRECTION
1. Check the electrical signal from the command
source. Current should flow in both directions. If
not, there is an electrical problem.
2. Jog the manual operator on top of the pilot. This
may free a contaminant in the pilot itself. If after
several jogs to either side the pump continues to
operate in only one direction, replace the pilot.
E. PUMP DOES NOT REACH FULL OUTPUT
1. Check the input current to the pilot. Verify that full
drivecurrentfromthecommandsourceisatleastas
high as that specified. See Data, Electrical, page 2.
2. If the current drive is high enough, jog the manual
operator on the pilot. If full output is attained,
replacethe pilot. If pumpoutputis lowonboth sides
ofnull,thefiltermaybepluggedinthesecondstage.
If the pump output is full on one side and low on the
other, replace the pilot.
F. PUMP NULL DEADBAND IS ASYMMETRICAL
1. Adjust the second stage null using the null adjust
procedure described previously.
2. If the problem persists and the noise from the pump
on either side of null indicates that null is unstable
(i.e., the pump creeps), replace the pilot.
See Customer Service, below, for repairs and re-
turns.
CUSTOMER SERVICE
IN NORTH AMERICA ORDER FACTORY INSTALLED
EDC ON PUMP FROM
Danfoss (US) Company
2800 East 13th Street
Ames, Iowa 50010
Telephone: [phone]
Fax: [phone]
IN NORTH AMERICA ORDER INDIVIDUAL EDCs FROM
Danfoss (US) Company
Customer Service Department
3500 Annapolis Lane North
Minneapolis, Minnesota 55447
Phone: [phone]
Fax: [phone]
DEVICE REPAIR
For devices in need of repair or evaluation, include a
description of the problem and what work you believe
needs to be done, along with your name, address and
telephone number.
RETURN TO
Danfoss (US) Company
Return Goods Department
3500 Annapolis Lane North
Minneapolis, Minnesota 55447
© Danfoss, 2014-05 11152452 • Rev AA • May 2014 12