Danfoss PVE Series 7 Electrohydraulic Actuators

Introduction

This manual provides information for troubleshooting and servicing PVE actuators used with PVG 32, PVG 100, PVG120, and certain EH steerings. It does not cover the PVG system in general or steering systems.

The PVE (Proportional Valve Electric actuator) is an electro-hydraulic actuator designed to control a single work section of a PVG proportional valve group. The PVE Series 7 program offers variants with different performance levels and features compatible with PVG 32/100/120/128/256.

The actuator positions the main spool within a PVG work section to control flow or pressure. It receives an analog voltage signal for remote operation via joysticks or controllers. The electro-hydraulic solenoid valve bridge uses various regulation principles depending on the variant. The actuator distributes pilot oil pressure to position the spool, featuring closed-loop spool control and continuous fault monitoring.

The analog PVE Series 7 program includes five main hydraulic principle variants: PVEO, PVEM, PVEA, PVEH, and PVES. These, combined with different solenoid valve regulation principles, determine whether the actuator controls the spool proportionally or via ON/OFF signals.

Image Description: A diagram shows a typical valve section with a PVE actuator mounted. Components labeled include PVE, LVDT, Electronics, PVBS, PVB, PVM, SV1, SV2, B-port, and A-port. The diagram illustrates the PVE controlling the spool position via pilot oil pressure, with an alternative manual control via PVM.

For general descriptions, specifications, and operating parameters of PVG valves and actuators, refer to the relevant Technical Information listed in the Danfoss Literature Reference. Danfoss technical literature is available at www.danfoss.com.

A global network of Danfoss Service Partners is available for major repairs. You can find your nearest partner via the distributor locator at www.danfoss.com.

⚠️ Warning: Do not attempt to service PVG valves without build sheet specifications for reference.

Abbreviations Chart

The following table lists abbreviations used for PVG/PVE systems:

Danfoss Literature Reference:

Warnings

⚠️ Warning: Not applying to the Operational Conditions can compromise safety.

All brands and types of directional control valves, including proportional valves, can fail and cause serious damage. It is crucial to analyze all application aspects. The machine builder/system integrator is solely responsible for product selection and ensuring all performance, safety, and warning requirements are met, as proportional valves are used in diverse conditions.

A PVG with PVE can only perform as described if the conditions in this Technical Information are met.

For particularly exposed applications, a shield is recommended.

When the PVE is in fault mode, performance quality and feedback validity are limited, depending on the fault type.

Error pins from multiple PVEs must not be connected together. Inactive error pins are connected to ground and will disable any active signal. Error pins are signal pins and can only supply very limited power consumption.

Deviations from recommended torque during part mounting can harm performance and the module.

Adjustment of the position transducer (LVDT) affects calibration, safety, and performance.

When replacing the PVE, ensure the electrical and hydraulic systems are turned off and oil pressure is released.

PVEA is not for use on PVG 100.

Hydraulic oil can cause environmental damage and personal injury.

Module replacement can introduce contamination and system errors. Maintaining a clean work area and handling components with care is essential.

After replacing modules or cables, verify wiring quality through a performance test.

Actuation at voltages below nominal will result in reduced PVG performance.

The PVE is not designed for use with voltages outside the nominal range.

Obstacles in the pilot oil path can directly influence spool control.

Reduced pilot oil pressure will limit spool control.

Excessively high pilot oil pressure can damage the PVE.

General Information

General Instructions

Follow these general procedures when servicing PVG 32 valves:

Avoid injuries or material damage

• Plan the process thoroughly. Block wheels and other moving parts to prevent undesired movement.
• Secure against hydraulic fluid leakage. Hydraulic fluid can cause contamination, burns due to temperature, and other injuries due to high pressure. Follow all instructions from the machine builder.

Keep it clean

• Cleanliness is paramount for ensuring a long application lifetime. Clean the outside of the valve thoroughly before any disassembly. Cap ports and hoses when opening. Avoid contamination by dirt and chemical agents. Clean parts using a clean solvent wash and air dry.

Replace all O-rings and gaskets

• Danfoss recommends inspecting O-rings and gaskets and replacing them if wear or contamination is evident. Dried-out O-rings and gaskets must be replaced.

Safety Precautions

Always consider safety precautions before beginning a service procedure. Protect yourself and others from injury. Follow machine manufacturer instructions carefully. Read and incorporate warnings from the relevant PVG literature into your work planning.

⚠️ Warning: Ensure stable conditions. Manipulation of mechanical, hydraulic, and electrical systems can create dangerous situations. Ensure all necessary precautions are taken to prevent dangerous situations.

⚠️ Warning: Release hydraulic pressure in system. Shut down the pump and release pressure in all work functions, tank, and pilot circuits if not already released.

⚠️ Warning: Disengage electrical system. Disengage power supply and system control. If relevant for the application, disengage system output (e.g., error pin, direction indicator).

Connector Overview

The following tables detail the pin assignments for various PVE connector types:

PVEO/PVEO-R/PVEO-HP

PVEO-DI

PVEM

PVEA/PVEH/PVES

PVEA-DI/PVEH-DI

PVEH-FLA

PVEH-SP/PVES-SP

Connector Diagrams Description:

• 1x4 DEUTSCH: A rectangular connector with 4 pins, labeled 1, 2, 3, 4.
• 1x6 DEUTSCH: A rectangular connector with 6 pins, labeled 1 through 6.
• 2x4 DEUTSCH (A & B): Two rectangular connectors, each with 4 pins. Connector A is labeled 1-4, Connector B is labeled 1-4.
• 1x4 AMP: A rectangular connector with 4 pins, labeled 1, 2, 3, 4.
• 1x6 AMP: A rectangular connector with 6 pins, labeled 1 through 6.
• 2x4 AMP: A rectangular connector with 8 pins, arranged in two rows of 4, labeled 1-4 and 1-4.
• 1x4 DIN: A circular connector with 4 pins, labeled 1, 2, 3, 4.

Hydraulic Principle Variants

The PVE Series 7 actuator program includes variants with different hydraulic principles:

Principle of PVEO/PVEO-R/PVEO-DI

Description: This diagram shows a PVEO-DI actuator. It includes a microcontroller, LED circuit, power supply, LVDT, and two solenoid valves (SV1, SV2) controlling pilot oil flow (Ramp). The system is connected to pilot pressure (Pp) and uses digital inputs (DI_A, DI_B) for direction indication.

Principle of PVEM

Description: This diagram illustrates a PVEM actuator. It features a microcontroller, LED, error output, power supply, and LVDT. It controls pilot oil flow via two solenoid valves (SV1, SV2) to position the spool, connected to pilot pressure (Pp).

Principle PVEA

Description: This diagram depicts a PVEA actuator. It includes a microcontroller, LED, error output, power supply, and LVDT. It uses normally closed solenoid valves (NC1, NC3) and normally open solenoid valves (NO2, NO4) to control pilot oil distribution to position the spool, connected to pilot pressure (Pp).

Principle of PVEH

Description: This diagram shows a PVEH actuator. It features a microcontroller, LED, error output, power supply, and LVDT. It uses normally closed solenoid valves (NC1) and normally open solenoid valves (NO2) to control pilot oil distribution to position the spool, connected to pilot pressure (Pp).

Principle of PVES

Description: This diagram illustrates a PVES actuator. It includes a microcontroller, LED, error output, power supply, and LVDT. It uses normally closed solenoid valves (NC1, NC3) and normally open solenoid valves (NO2, NO4) to control pilot oil distribution to position the spool, connected to pilot pressure (Pp).

Troubleshooting Actuator

For warranty claims, verify and describe the following points before replacing an actuator:

Function of external parts

• Spool can move as expected when activated by PVM.
• Pilot pressure is available.
• Control signal can activate other PVE/PVHC.
• Cabling is undamaged.
• Connectors are sealed and dry.

Function of PVE

• Failure is temporary/continues.
• Failure is in one direction (A or B) or both.
• Visible damage.

Exchanging PVE

These guidelines point out issues related to the application, the PVG, and its actuator. Danfoss does not provide directives on how work should be planned or supervised.

Before replacing or dismounting a PVE

1. Ensure the actuator needs to be dismounted. Follow the troubleshooting procedure to confirm the failure is not elsewhere in the application (refer to Service Manual for PVG32 and PVG100).
2. Clean the PVG surroundings for dirt and rust/oxidations. Avoid cleaning agents or methods requiring higher IP ratings than the actuator supports.
3. Prepare a clean area for the new PVE/PVHC before mounting.
4. Prepare a clean area for the old PVE/PVHC before returning it for investigation.
5. Have the correct tools ready.
6. Ensure the spare part is the correct actuator.
7. Unpack the replacement actuator:
   • If the actuator has an LVDT, avoid mishandling and bending it.
   • Ensure all O-rings are in place.
   • Ensure new bolts are provided.
   • Ensure any electrical connector sealing is present.
   • If necessary, clean off excessive oil with a soft tissue. The PVE should still have a thin oil film.
   • Keep the actuator protected from pollution throughout the process; store it in a bag.

Mounting of PVE variants

Image Description: Two diagrams show mounting details for PVE variants. The first shows "PVEO/M/A Series 7" and the second shows "PVEH/S Series 7". Both indicate a mounting dimension of 5 [0.2] and a torque specification of 8 ± 0.5 N·m [70 ± 4.4 lbf·in].

Dismounting of PVE

1. Remove connector(s) from PVE:
   • Pull the connector, not the cable.
   • Verify if the cable and connectors can be reused or must be replaced (e.g., check isolation, lock).
2. Loosen and unscrew bolts counter-clockwise. Be aware of leaking oil.
3. Remove the PVE/PVHC carefully:
   • Do not introduce pollution to the PVB or actuator. Marked areas are particularly sensitive to pollution.
   • Ensure O-rings are removed with the actuator.
   • Place the removed actuator safely in a bag.
4. If necessary, clean the PVB carefully with a soft tissue to ensure a clean interface for the replacement actuator.

Mounting of Replacement

1. Avoid contamination, including oil in connectors.
2. Avoid damaging the LVDT pin.
3. Depending on the PVB, position the actuator or all bolts in the actuator bolt holes.
4. Reassure that O-rings are in place on the actuator.
5. Place the actuator onto the PVB and screw in bolts loosely and clockwise.
6. Tighten bolts to the torque indicated in the instructions.
7. Connect wiring.

Test and use of PVG and Actuator

After actuator replacement, the system must be tested according to manufacturer guidelines. Ensure safety functions and performance meet demands.

Before restart, bleed the system. PVG can be bled via PVM. Let the application run; in worst-case scenarios, air must be flushed out by oil during up to 5 minutes of activation.

Returning Replaced Actuator for Customer Claims

If a replaced actuator is returned to Danfoss for malfunction analysis, a description of the malfunction and application must be submitted. Refer to the form in the "returning claims" section.