Danfoss H1 User Manual (English)

Other manuals for Danfoss H1

Basic Information40 pages

Technical Information68 pages

Questions and Answers:

R
Rhonda JohnsonAug 16, 2025
What to do if Danfoss H1 Water Pump transmission operates normally in one direction only?
- L
  Lori DavisAug 16, 2025
  If your Danfoss Water Pump transmission operates normally in only one direction, the issue could stem from several causes. The input to the control module might be operating improperly; check the control input and repair or replace it as necessary. Control orifices or screens could be blocked; clean the orifices and clean or replace the screens. Interchanging the charge check/HPRVs can help determine if the problem is valve-related; if the problem changes direction, replace the valve that doesn't operate correctly. Low or decaying servo pressure is another possibility; check for damaged servo seals, replace them, and retest.
R
Reginald MitchellAug 19, 2025
Why Danfoss H1 Water Pump control operates the pump in one direction only?
- S
  samantha26Sep 12, 2025
  If your Danfoss Water Pump control operates the pump in only one direction, it could be due to control coil failure. Measure the resistance at the coil pins; it should be 14.2W (24V) or 3.66W (12V) at 20° C [70° F]. If it's not, replace the coil.
S
Shelby RamirezAug 22, 2025
What to do if Danfoss H1 has erratic or no machine function?
- D
  Dennis BarrettAug 22, 2025
  If your Danfoss Water Pump is showing erratic or no machine function, it could be due to an external controller malfunction or a hydraulic system problem. To check for a controller issue, verify the external controller problem using a spare controller and replace it if necessary. Also, check the hydraulic system fluid level, pressures, filters, and address any hydraulic system problems.
J
jason74Aug 28, 2025
What to do if Danfoss H1 system has noise or vibration?
- D
  Daniel AnthonyAug 28, 2025
  If your Danfoss Water Pump system is experiencing noise or vibration, several issues could be the cause. Low oil level can lead to cavitation, so start by filling the reservoir. Air in the system can also cause noise, foaming, and hot oil; locate and repair where air is entering, and ensure the inlet line isn't restricted and is the proper size. Cold oil may be too viscous, causing the pump to cavitate; allow the oil to warm up at idle speed. A high inlet vacuum can also cause noise/cavitation; check the inlet line and filter. Other potential causes include a loose input shaft coupling (replace it), misaligned shafts (correct the misalignment), or sticking valves (clean/replace them). If the noise is unusual, contamination may be present.
J
Jenny ParkSep 2, 2025
What to do if Danfoss Water Pump system will not operate in either direction?
- V
  victoriajimenezSep 2, 2025
  If your Danfoss Water Pump system isn't operating in either direction, it could be due to insufficient hydraulic fluid; ensure the reservoir is filled to the proper level. Another possibility is blocked control orifices or screens; clean the control orifices and clean or replace the control screens.
S
Sara SmithSep 6, 2025
What to do if I can't find neutral on my Danfoss H1?
- B
  bcrawfordSep 6, 2025
  If you're having trouble finding neutral on your Danfoss Water Pump, first disconnect the input to the control module and see if the pump returns to neutral. If it does, there's an input fault, so replace or repair the external controller. If not, shunt servo gauge ports M4 and M5 together with an external hose and see if the pump returns to neutral. If yes, the control neutral is improperly set. If no, balance the swashplate. If you still cannot set neutral, replace control.
J
Jacqueline BarnesSep 8, 2025
Why is there no pump function in my Danfoss Water Pump?
- N
  nataliesawyerSep 9, 2025
  If there is no pump function in your Danfoss Water Pump, it could be due to no power to the controller. Restore power to the controller.
C
Cathy HawkinsSep 12, 2025
Why is my Danfoss H1 function erratic?
- M
  maysandreaSep 12, 2025
  If your Danfoss Water Pump is functioning erratically, the electrical connection to the pump might be bad. Disconnect the connection, check the wires, and then reconnect them.

Danfoss H1 Specifications

General

Brand	Danfoss
Model	H1
Category	Water Pump
Language	English

Summary

Introduction

Overview

General overview of the H1 tandem pumps, components, troubleshooting, and repair.

Warranty

Information regarding warranty coverage for adjustments and repairs.

General Instructions

Procedures for pump removal, cleanliness, and general handling during repair.

Safety Precautions

Critical safety warnings for handling hydraulic systems and equipment.

Symbols Used in Danfoss Literature

Legend explaining symbols used throughout the manual for clarity.

Design

Explanation of the H1 tandem pump's design and operating principles.

Cross Section View

Detailed diagram showing the internal components of the pump.

Pump Schematic

Diagram illustrating the hydraulic circuit of the 045/053 tandem pump.

The System Circuit

Explanation of the basic closed circuit and case drain/heat exchanger functions.

Operation

Pressure Limiter Valves (060/068 only)

How pressure limiter valves provide system pressure protection and regulate displacement.

High Pressure Relief Valve (HPRV) and Charge Check

Function of HPRV for limiting system pressure and charge check for replenishing low-pressure side.

Charge Pressure Relief Valve

How the charge pressure relief valve maintains charge pressure above case pressure.

Electrical Displacement Control (EDC)

Principle and operation of EDC for controlling pump displacement via electrical signals.

Manual OverRide (MOR)

Feature for temporary actuation of pump control for diagnostic purposes.

Manual Displacement Control (MDC)

How MDC uses a handle to provide proportional displacement control.

MDC Torque

Specifications for torque required to operate the MDC handle.

MDC General Information

Details on MDC deadband, end stops, and case pressure effects.

Neutral Start Switch (NSS)

Function of NSS to provide a signal for control neutral status.

Neutral Start Switch Data

Electrical specifications for the Neutral Start Switch.

Case Gauge Port M14

Usage of the M14 port for flushing residual contamination.

Control-Cut-Off (CCO) Valve and Brake Valve

Function of the optional CCO valve and separate brake release valve.

045-053 Tandem Schematic

Hydraulic schematic for the 045-053 tandem pump configuration.

060/068 Schematic

Hydraulic schematic for the 060/068 tandem pump configuration.

Solenoid Data

Electrical data for control solenoids used in the pumps.

Solenoid Data (Continued)

Further electrical specifications and IP ratings for solenoids.

Connector

Information on the electrical connector used with the pump.

Connector Ordering Data

Part numbers and quantities for ordering connector components.

Operating Parameters

Overview

Introduction to input speed and pressure operating parameters and limitations.

Input Speed

Definition and limitations of minimum, rated, and maximum input speeds.

System Pressure

Explanation of system pressure, applied pressure, rated pressure, and maximum pressure.

Charge Pressure

Role of external charge pump, charge relief valve, and minimum/maximum charge pressures.

Charge Inlet Pressure

Requirements for charge inlet pressure at various operating conditions.

Case Pressure

Limitations and cautions regarding case pressure operation.

Temperature and Viscosity

Guidelines for optimal fluid temperature and viscosity for performance and life.

Technical Specifications

H1T General Specifications

Design, rotation, connections, installation position, and cavity pressure.

Technical Data H1 Tandem

Detailed specifications for displacement, flow, torque, mass, volume, and mounting.

Operating Parameters H1 Tandem

Specific operating parameters like speed, pressure, and control pressure for H1 Tandem.

Fluid Specifications

Viscosity and temperature range recommendations for hydraulic fluid.

Viscosity and Temperature Range

Detailed table of viscosity and temperature limits for optimal operation.

Fluid and Filter Maintenance

Fluid and Filter Recommendations

Procedures for maintaining fluid cleanliness and filter integrity for unit life.

Hazardous Material

Warning regarding hazardous nature of hydraulic fluid and proper disposal.

Fluid and Filter Change Interval

Recommended intervals for changing hydraulic fluid and filters.

Pressure Measurements

Port Locations and Gauge Installation - 045/053

Identification of ports and gauge sizes for pressure testing on 045/053 models.

Port Locations and Gauge Installation - 060/068

Identification of ports and gauge sizes for pressure testing on 060/068 models.

Initial Startup Procedures

General

Pre-installation checks and general advice for starting up a new or reinstalled pump.

Start-up Procedure

Step-by-step guide for safely starting up the pump and bleeding air.

Troubleshooting

Overview

General steps for troubleshooting undesirable system conditions.

Safety Precautions

Essential safety warnings to be observed during troubleshooting.

Electrical Troubleshooting

Steps to diagnose and resolve electrical issues affecting pump operation.

Neutral Difficult or Impossible to Find

Troubleshooting steps for issues related to setting pump to neutral.

System Operating Hot

Causes and solutions for the system overheating.

Transmission Operates Normally in One Direction Only

Troubleshooting guide for unidirectional pump operation.

System Will Not Operate in Either Direction

Steps to diagnose and fix complete pump operational failure.

System Noise or Vibration

Identifying and resolving issues causing noise or vibration in the system.

Sluggish System Response

Diagnosing and rectifying slow or unresponsive system behavior.

Adjustments

Pump Adjustment

Instructions for inspection and adjustment of pump components.

Standard Procedures

General procedures to follow before performing any pump adjustments.

Charge Pressure Relief Valve Adjustment

Procedure for checking and adjusting the charge pressure relief valve.

Charge Check / HPRV Adjustment

Information on adjusting and checking the charge check/HPRV function.

Pressure Limiter Adjustment (060/068 only)

Procedure for adjusting the pressure limiter setting on 060/068 models.

Pressure Limiter Valve Adjustment - Clockwise

Method for adjusting the pressure limiter valve in clockwise direction.

Pressure Limiter Valve Adjustment - Counterclockwise

Method for adjusting the pressure limiter valve in counterclockwise direction.

Engaging the Bypass Function (060/068 only)

Procedure to bypass the pump for moving vehicles short distances.

Displacement Limiter Adjustment

How to adjust displacement limiters to set maximum displacement.

Control Neutral Adjustment

Procedure for setting the control to neutral for EDC, MDC, and FNR controls.

Mechanical Neutral Adjustment

Detailed steps for setting mechanical neutral for pump sections.

Pump Setup

Steps involved in setting up the pump, including gauge connections.

Servo Adjustment

Procedures for adjusting servo and system pressure.

Servo and System Pressure Gauge Port Locations (45/53)

Identification of ports for servo and system pressure on 45/53 models.

Servo and System Pressure Gauge Port Locations (60/68)

Identification of ports for servo and system pressure on 60/68 models.

Minor Repair

Standard Procedures, Removing the Pump

General procedures for removing the pump and ensuring system cleanliness.

Electric Control Module

Steps for removing, inspecting, and reassembling the electric control module.

Control Solenoids

Procedures for removal, inspection, and reassembly of control solenoids.

MDC Control

Steps for removing and disassembling the MDC control module.

Angle Sensor on EDC

Procedures for removing and installing the angle sensor on EDC.

Front Shaft, Seal, and Bearing

Steps for removing and replacing the front shaft, seal, and bearing.

Charge Pump (045/053 only)

Procedures for removing, inspecting, and reassembling the charge pump for 045/053 models.

Charge Check / HPRV (45/53)

Removal, inspection, and reassembly of charge check/HPRV for 45/53 models.

HPRV (60/68)

Procedures for removing, inspecting, and reassembling HPRV for 60/68 models.

Charge Pressure Relief Valve

Steps for replacing the charge pressure relief valve.

Control Cutoff Valve and Brake Valve

Procedures for removal, inspection, and reassembly of control cutoff and brake valves.

Torque Chart

Fastener Size and Torque Chart

Table listing fasteners, their sizes, and corresponding torque values.

Plug Size and Torque Chart

Table listing plugs, their sizes, and corresponding torque values.

Fastener and Plug Locations (045/053)

Diagrams showing the locations of fasteners and plugs on 045/053 models.

Fastener and Plug Locations (060/068)

Diagrams showing the locations of fasteners and plugs on 060/068 models.

Related product manuals

Danfoss H1 User Manual

Table of Contents

Other manuals for Danfoss H1

Questions and Answers:

Danfoss H1 Specifications

Summary

Introduction

Overview

Warranty

General Instructions

Safety Precautions

Symbols Used in Danfoss Literature

Design

Cross Section View

Pump Schematic

The System Circuit

Operation

Pressure Limiter Valves (060/068 only)

High Pressure Relief Valve (HPRV) and Charge Check

Charge Pressure Relief Valve

Electrical Displacement Control (EDC)

Manual OverRide (MOR)

Manual Displacement Control (MDC)

MDC Torque

MDC General Information

Neutral Start Switch (NSS)

Neutral Start Switch Data

Case Gauge Port M14

Control-Cut-Off (CCO) Valve and Brake Valve

045-053 Tandem Schematic

060/068 Schematic

Solenoid Data

Solenoid Data (Continued)

Connector

Connector Ordering Data

Operating Parameters

Overview

Input Speed

System Pressure

Charge Pressure

Charge Inlet Pressure

Case Pressure

Temperature and Viscosity

Technical Specifications

H1T General Specifications

Technical Data H1 Tandem

Operating Parameters H1 Tandem

Fluid Specifications

Viscosity and Temperature Range

Fluid and Filter Maintenance

Fluid and Filter Recommendations

Hazardous Material

Fluid and Filter Change Interval

Pressure Measurements

Port Locations and Gauge Installation - 045/053

Port Locations and Gauge Installation - 060/068

Initial Startup Procedures

General

Start-up Procedure

Troubleshooting

Overview

Safety Precautions

Electrical Troubleshooting

Neutral Difficult or Impossible to Find

System Operating Hot

Transmission Operates Normally in One Direction Only

System Will Not Operate in Either Direction

System Noise or Vibration

Sluggish System Response

Adjustments

Pump Adjustment

Standard Procedures

Charge Pressure Relief Valve Adjustment

Charge Check / HPRV Adjustment

Pressure Limiter Adjustment (060/068 only)

Pressure Limiter Valve Adjustment - Clockwise

Pressure Limiter Valve Adjustment - Counterclockwise

Engaging the Bypass Function (060/068 only)

Displacement Limiter Adjustment

Control Neutral Adjustment