MCV102A. Pressure Control Servovalve DESCRIPTION FEATURES ORDERING INFORMATION. BLN Issued: October 1998

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1 MCV102A Pressure Control Servovalve Issued: October 1998 DESCRIPTION The MCV102A Pressure Control Servovalve (PCS) is a twostage, fourway, closed loop electrohydraulic servovalve that provides an output differential pressure in response to a low power electrical input signal. The PCS consists of a closed loop Pressure Control Pilot Valve and a closed loop pressure control boost stage valve. The boost stage valve features a unique double-spool arrangement that has significant cost and functional advantages over conventional single-spool deigns. The PCS has been designed with an output dynamic response bandwidth sufficient for most high performance servo control applications. The valve may be used to directly control cylinders, to control output forces, or as a first stage to pilot operated high flow main control valves of 40 gpm to 400 gpm flow rates. FEATURES Null shift stability over a wide temperature and pressure range Constant pressure gain regardless of supply pressure, return pressure and load flow demand changes Independent dual spool operation maximizes load flow output while maintaining proper differential pressure Compatible with standard 10 micron nominal filtration Pilot stage manual operator allows hydraulic operation to be verified without electrical signal Configured for direct manifold mounting GM Packard or MS Connector available ORDERING INFORMATION SPECIFY 1,2 MCV102A100 (PCS with Packard Connector) MCV102A1014 (PCS with MS Connector) MCV102A2103 (PCS dual coil MS Connector) 9 SPARE PARTS 8 ITEM NUMBER PART NUMBER DESCRIPTION 1 K01314 Device MS Connector 2 K0810 Mating MS Connector (Bag Assembly) 3 K03377 Device Connector 2-Pin (Unassembled) 5 3,4 4 K03383 Mating Connector 2-Pin (Unassembled) 5 K00829 O-Ring (.34 ID x.070) K00834 O-Ring (1.24 ID x.070) 7 K00830 O-Ring (.43 ID x.070) 8 K04793 Socket head cap screw X 3/ A 9 K Ring (.551 ID x.070) Location of Spare Parts Item Number. Mounting manifolds may be made available upon customer request. Danfoss,

2 TECHNICAL DATA ELECTRICAL RATED FULL PRESSURE CURRENT See Two Spool, Pressure Control, Static Gain (Single Coil). ±150 ma (single coil ) (23 ohm) ±200 ma (dual coil) (19 and 15.5 ohm) Maximum input signal is ±250 ma, which will increase PCS output differential pressure range to approximately 1.2 times that obtained at rated input signal at rated supply pressure. COIL 24 C (7 F) 23 ohms (single coil) 19 ohms and 15.5 ohms (dual coil) COIL INDUCTANCE.14 Henries (single coil).02 Henries (19 ohms, dual coil),.047 Henries (15.5 ohms, dual coil) MAXIMUM CONTINUOUS VOLTAGE 7.5 Vdc at 93.3 C (200 F) HYDRAULIC FLUID Petroleum based standard. Other with compatible seals OIL VISCOSITY 40-20,000 SSU FLUID AND AIR OPERATING TEMPERATURE RANGE -40 to 104 C (-40 to 220 F) FLUID AND AIR RATED TEMPERATURE RANGE -29 to 104 C (-20 to 220 F) 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 equipment controls consisting of two parts: 1. Cycling from 5 to 2000 Hz in each of the three axes. 2. Resonance dwell for one million cycles for each resonance point in each of the three axes. Subject to acceleration levels of 1 to 4 G's. Acceleration level varies with frequency. HUMIDITY After being placed in a controlled atmosphere of 95% humidity at 49 C (120 F) for 10 days, the PCS will perform within specification limits. Meets MIL-STD- 810B. PERFORMANCE LOAD FLOW CURVE See Two Spool, Pressure Control, Load-Flow Curve (Single Coil). SUPPLY PRESSURE 1000 psi maximum 500 psi rated 150 psi minimum RETURN PRESSURE Atmospheric to 300 psi SUPPLY FILTRATION 10 micron nominal recommended RATED OUTPUT DIFFERENTIAL PRESSURE AT 500 PSI SUPPLY PRESSURE ±225 psid (23 ohms, single coil) ±15 psid (19 and 15.5 ohms, dual coil) With output ports blocked RATED OUTPUT FLOW RATE. gpm minimum (single coil) With an output load pressure of 175 psid.7 gpm minimum (dual coil) With an output load pressure of 100 psid TWO SPOOL, PRESSURE CONTROL, STATIC GAIN (SINGLE COIL) OUTPUT DIFFERENTIAL PRESSURE (psid) CURRENT INPUT (ma) A 2

3 TECHNICAL DATA (continued) NEUTRAL LEAKAGE 1.2 gpm maximum Consisting of pilot stage valve quiescent flow plus boost stage neutral leakage OUTPUT PORT NULL PRESSURE 0 psid With supply pressure at 500 psi above return pressure, each output port pressure will be 115 psi nominal THRESHOLD Less than 1% of rated input signal HYSTERESIS 5% of rated input signal, maximum LINEARITY Within 5% of rated signal, maximum Pressure linearity is the deviation from the best straight line pressure gain curve in either direction expressed as a percentage of rated input signal. Null region (±4% signal) pressure gain may vary from 50 to 200% of nominal pressure gain due to boost stage null adjustment. Pressure linearity in each direction is specified from 4% to 90% input signal with a constant pressure drop across the valve. SYMMETRY Will not exceed 5% in each direction Symmetry is the difference in output differential pressure in each direction at rated input signal expressed as a percentage of the mean output differential pressure. TWO SPOOL, PRESSURE CONTROL, LOAD-FLOW CURVE (SINGLE COIL) LOW PRESURE VERSION Pressure control servovalve Supply pressure: 500 psi LOAD-FLOW (P-Q) CURVE - PCS 10 FLOW (gpm) ma 50 ma 75 ma ma 125 ma 150 ma 175 ma 200 ma 225 ma 250 ma ma 200 ma 225 ma 175 ma 150 ma 125 ma 100 ma 75 ma 50 ma 25 ma A TECHNICAL DATA (continued) PRESSURE NULL SHIFT < ±1.5% (23 ohms, single coil) < ±1.0% (19 and 15.5 ohms, dual coil) TEMPERATURE NULL SHIFT < ±3 psid (23 ohms, single coil) < ±2 psid (19 and 15.5 ohms, dual coil) by a current driver-type amplifier. The oil trapped between the two output ports does not exceed.4 cubic inches. See Two Spool, Pressure Control, Dynamic Response. DIMENSIONS See Dimensions FREQUENCY RESPONSE 85 Hz minimum at -3db 70 Hz minimum at 90 phase lag Specified at 500 psi supply pressure above return pressure, blocked output ports and an input signal of ±30% to ±50% of rated input signal. The PCS is driven 3

4 TWO SPOOL, PRESSURE CONTROL, DYNAMIC RESPONSE LOW PRESURE VERSION Pressure control servovalve ±20 ma input Supply pressure: 500 psi Differential pressure output 20 x LOG MAGNITUDE BODE PLOT FREQUENCY (Hz) PHASE (DEGREES) FREQUENCY (Hz) 1255B DIMENSIONS 3/8 O.D. TUBE FITTING O-RING PORT, PER SAE J514 9/1 18 UNF (2) PL. (PLUGS INSTALLED) NULL ADJUST ACCESS SCREW MANUAL OPERATOR OPTIONAL MS CONNECTOR 79,5 (3.12) ELECTRICAL CONNECTOR: HIGHER POTENTIAL AT RED LEAD PRODUCES FLOW OUT C2 TO LOAD, BACK TO C1. 140,7 mm ±0.03 (5.52) 11,53 mm ±0.03 (4.57) 1,20 (2.4) 8,9 (0.35) = SYSTEM PRESSURE P T = RETURN PRESSURE C 1 = OUTPUT CONTROL PORT 1 C 2 = OUTPUT CONTROL PORT 2 WEIGHT: 1.97 kg (4.33 lbs.) 5,4 (DIA.) (.221) 4 PL. 85, (3.37),1 (0.24) 19,05 (0.750) 34,9 (1.375) 38,1 (1.50) 11,4 (0.450) 4,77 (2.55) 38,1 (1.50) 7,2 (3.0) 1284A Dimensions of the MCV102A PCS in Millimeters (Inches). 4

5 THEORY OF OPERATION The MCV102A PCS uses a torque motor actuated, doublenozzle flapper pilot and a double-sliding spool boost stage. See Internal Workings Schematic. The current input to the pilot produces a proportional control output differential pressure to the second stage. The differential pressure is independent of supply pressure, return pressure and control characteristics of the valve. As the electrical input from the command source to the pilot stage is varied, the pressure signals (P1 and P2) to the boost stage change, with one increasing and the other decreasing. This causes the spool to seek a new position, with the higher INTERNAL WORKINGS SCHEMATIC pressure spool moving down and the lower pressure spool moving up. The new spool position is determined when a change in the spool land varies the orifice size between supply pressure and the appropriate work port (A or B), resulting in a new work pressure (PA or PB). The work pressure is fed back to the underside of the spool until it equals the pilot pressure. Spool modulation (which acts like dither) continues until, at equilibrium, the output differential pressure is equal to the input differential pressure. Power is boosted by retaining these pressures at a much higher flow rate capability. CONNECTION DIAGRAM AIR GAP ARMATURE POLE PIECE POLE PIECE COIL MAGNET PIVOT PLATE D C A B ORIFICE P1 FLAPPER P2 NOZZLE 127 P1 P2 P T Pa Pb Pa PORT "A" LOAD Pb PORT "B" Pressure Control Servovalve,Two Spool Design Pin Orientation of 4-pin, 90 MS Mating Connector. Part No. MS3108E-14S-2S (Danfoss Kit No. K0810). WIRING Two wiring styles are available: MS and GM Packard Connectors. The MS Connector is part number MS3108E- 14S-2S (Danfoss Kit No. K0810) and has four pins, two of which (A and B) are used. See Pin Orientation of the Optional MS Connector, Part Number MS3108E-14S-2S (Danfoss Kit No. K0810). The Packard Connector is a two pin connector. In both cases, phasing is such that a positive voltage on the Red wire (Pin B) will cause a pressure increase at the C2 port (see Dimensions). The Packard Connector PCS includes a bag assembly for the mating female connector half comprised of: 1. 2, 14-1 gauge sleeves 2. 2, gauge sleeves 3. 1 plastic housing 4. 2 green cable seals 5. 2 gray cable seals. 2 blue cable seals See Ordering Information. To assemble the female mating connector, use the following directions: 1. Isolate the wires that extend from the command source to the PCS. 2. Strip back the insulation 5.5 millimeters on both sides. 5

6 WIRING (continued) 3. Push 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. The distance from the tip of the wires to the first (nearest) rib should be 9.5 millimeters. Thus the installation should just protrude beyond the seal. 3. Push 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. The distance from the tip of the wires to the first (nearest) rib should be 9.5 millimeters. Thus the installation should just protrude beyond the seal. 4. Select the larger of the two sets of pins, as measured at Dimension A (see Dimension A drawing), if using 14-1 gauge wire. Choose the smaller if using gauge. Place the wire into the socket so that the seal edge is pushed through and extends slightly beyond the circular tabs that hold it in place. Crimp in the locations shown in Distance, Packard Connector diagram with a Packard crimp tool available from your local Packard distributor. 5. The distance from the back of the tangs to the furthest rib may not exceed 19.5 millimeters. See Distance, Packard Connector diagram.. 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 ensure proper seating. (Observe the proper phasing of the wires when installing: Black wire to A hole, Red to B.) Terminals may be removed from the connector bodies with a Packard removal tool. 7. Swing the holder down into the detented tower assembly. The two connector halves should detent into each other. See Connector Parts Identified, Packard Connector. DIMENSION A. DIMENSION A 1123 Dimension A For Selecting Correct Terminal. DISTANCE, PACKARD CONNECTOR CONNECTOR PARTS IDENTIFIED, PACKARD CONNECTOR CABLE SEALS SIDE "B" RED BLACK SIDE "A" SHROUD CONNECTOR DOUBLE-PLUG SEAL TOWER CONNECTOR 1077A 1078A Distance From Tang to Third Rib of Packard Connector. Interlocked Connector Halves With Parts Identified. Two Wire Connection Shown.

7 START UP PROCEDURE With the electrical connector at the PCS's pilot stage disconnected, apply hydraulic power to the system. If the load starts to drift, the PCS is off and will need adjustment. Use a 3/32 inch Allen wrench in the hole covered by the screw in the pilot cover. Do not exceed more than one turn in either THROUBLESHOOTING The most common failure of the pressure control system is sluggish or no response to electrical command from the cylinder. If this is the case, follow the procedure below: Jog the manual operator on the pilot valve. If the cylinder response is over its full range, disconnect the connector on the pilot stage. Use a voltohmeter to check the resistance across pins A and B. If the coil resistance is between 22 and 30 ohms, (single coil) check the resistance between each pin and the case. If the coil resistance is less than 1000 ohms, the pilot coil is bad and the valve should be replaced. If the coil resistance is greater than 1000 ohms, the PCS is receiving a bad electrical signal. Check the command source and the connecting cables. If the coil resistance is outside the ohms (single coil) range, the pilot is bad and the valve should be replaced. NORTH AMERICA ORDER FROM Danfoss (US) Company Customer Service Department 3500 Annapolis Lane North Minneapolis, Minnesota Phone: (73) Fax: (73) DEVICE REPAIR EUROPE ORDER FROM Danfoss (Neumünster) GmbH& Co. Order Entry Department Krokamp 35 Postfach 240 D Neumünster Germany Phone: Fax: 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