Universal Robots UR20 User manual

UR20
Service Manual
Compatible robots: UR20
Control Box: e-Series Control box 5.5, OEM Control Box,
Original instructions (en)

Contents
1.Introduction 1
1.1. About This Document 1
1.2. Company Details 1
1.3. Copyright and disclaimers 1
1.4. Safety Message Types 2
2.Handling ESD-Sensitive Parts 4
3.Recommended Inspection Activities 6
3.1. Robot Arm 6
3.1.1. Inspection Plan 6
3.1.2. Visual Inspection: Robot arm 6
3.1.3. Functional Inspection 8
3.1.4. Cleaning your robot 8
3.2. Control Box and Teach Pendant 8
3.2.1. Inspection Plan 8
3.2.2. Functional and Safety Inspection 9
3.2.3. Visual Inspection: Control Box 11
3.2.4. Cleaning 11
4.Service and Replacement of Parts 12
4.1. Pre-Use Assessment 12
4.1.1. Recommended Tools 13
4.2. Robot Arm 14
4.2.1. Connection Torque Values 15
4.2.2. Clamp Connection 17
4.2.3. Tool Flange 21
4.2.4. Replacement of Trim Plates 23
4.2.5. Joint Verification 24
4.2.6. Dual Robot Calibration 24
4.2.7. Program Correction by Key Waypoints 25
4.3. Control Box 25
4.3.1. Dismantling the Control Box 25
4.3.2. Torque Values 26
4.3.3. Replacing the 3PE Teach Pendant 27
5.Software 29
Service Manual UR20
Copyright © 2009–2023 by UniversalRobotsA/S. All rights reserved.

5.1. Software Updates 29
5.1.1. Update Procedure 29
5.2. Using Support File 30
5.3. Using Magic Files 30
5.4. Backup of data 31
5.4.1. Hardware Requirements 32
5.4.2. Software Requirements 32
5.4.3. Accessing Linux Partition from Windows 32
5.4.4. Copying the data from SD card 32
6.Troubleshooting 34
6.1. Adding External Equipment for Troubleshooting Purpose 34
6.2. UR Log Viewer 34
6.3. LED indicators and Fuse on Safety Control Board 34
6.3.1. LED Indicators on Safety Control Board 34
6.3.2. Fuse 35
6.4. Complete Rebooting Sequence 35
6.5. Robot Stop 36
6.5.1. Ignoring Robot Stops 37
7.Electrical drawings 39
8.Packing and Shipping of Robot/Spare Parts 40
9.Change log 44
UR20 Service Manual
Copyright © 2009–2023 by UniversalRobotsA/S. All rights reserved.

1.Introduction
1.1. About This Document
The purpose of the Service Manual is to help Universal Robots (UR) users and integrators to safely
perform service-related operations and troubleshooting.
Universal Robots industrial robots are designed using high quality components to ensure a long life-
time. However, improper use of a robot or robot parts can potentially cause failures. If, for example,
the robot is overloaded, dropped during relocation, damaged by collision, or any other improper
usage, the warranty will be void.
Universal Robots recommends the user does not attempt repair, adjustment, or make other inter-
ventions in the mechanical or electrical systems of the robot without first consulting a UR certified
service engineer. Any unauthorized intervention voids the warranty. Service-related operations and
troubleshooting should only be performed by qualified personnel.
Before performing service-related operations, stop the robot program and disconnect the main
power to any potential dangerous tool on the robot or in the surroundings.
In the event of a defect, Universal Robots recommends ordering new parts from the Universal
Robot distributor where the robot was originally purchased. Alternatively, parts can be ordered
from the nearest distributor, details of which can be obtained from Universal Robots official web-
site at www.universal-robots.com
1.2. Company Details
Universal Robots A/S
Energivej 25
DK-5260 Odense Denmark
Tel.: [phone]
Fax: [phone]
1.3. Copyright and disclaimers
The information contained herein is the property of UniversalRobotsA/S and shall not be repro-
duced in whole or in part without prior written approval of UniversalRobotsA/S. The inform-
ation herein is subject to change without notice and should not be construed as a commitment
by UniversalRobotsA/S. This document is periodically reviewed and revised.
UniversalRobotsA/S assumes no responsibility for any errors or omissions in this document.
Copyright © 2009–2023 by UniversalRobotsA/S.
The UniversalRobots logo is a registered trademark of UniversalRobotsA/S.
Service Manual 1 UR20
1.Introduction
Copyright © 2009–2023 by UniversalRobotsA/S. All rights reserved.

NOTICE
UniversalRobots continues to improve reliability and performance of its products,
and therefore reserves the right to upgrade the product without prior warning.
UniversalRobots takes care that the content of this document is precise and
correct, but takes no responsibility for any errors or missing information.
NOTICE
UniversalRobots disclaims any liability, even if all guidelines in this document are
followed.
1.4. Safety Message Types
Safety messages and statements are used throughout this manual to emphasize important inform-
ation.
Read all messages and statements to help ensure safety and to prevent injury to personnel and
product damage.
The safety message types are defined below.
WARNING
Indicates a hazardous situation which, if not avoided, could result in death or
serious injury.
WARNING: ELECTRICITY
Indicates a hazardous electrical situation which, if not avoided, could result in
death or serious injury.
WARNING: HOT SURFACE
Indicates a hazardous hot surface where injury can result from contact and non-
contact proximity.
CAUTION
Indicates a hazardous situation which, if not avoided, could result in injury.
GROUND
Indicates grounding.
UR20 2 Service Manual
1.Introduction
Copyright © 2009–2023 by UniversalRobotsA/S. All rights reserved.

PROTECTIVE GROUND
Indicates protective grounding.
NOTICE
Indicates the risk damage to equipment and/or useful information that should be
particularly noted.
READ MANUAL
Indicates more detailed information that should be consulted in the manual.
This warning draws attention to procedures which serve to prevent or remedy emergencies or mal-
functions:
MANDATORY ACTION
Procedures marked with this warning must be followed exactly.
Service Manual 3 UR20
1.Introduction
Copyright © 2009–2023 by UniversalRobotsA/S. All rights reserved.

2.Handling ESD-Sensitive Parts
To prevent damage to ESD-sensitive parts i.e. Printed Circuit Board, follow the instructions below in
addition to all the usual precautions, such as turning off the power before removing the circuit
boards. See section Complete Rebooting Sequence
NOTICE
Be sure you have intact ESD Wristband and a spare ESD bag before replacing any
ESD-sensitive parts.
NOTICE
Keep the ESD-sensitive part in its original shipping container (a special "ESD bag")
until the part is ready to be installed.
NOTICE
Put the ESD wristband on your wrist. Connect the wristband to the system ground
point.
It discharges any static electricity in your body to ground.
NOTICE
Replacing an ESD-sensitive part in a safe way is important to avoid damage to the
part. It is important to take precautions when handling an ESD-sensitive part.
NOTICE
Hold the ESD-sensitive part by its edges. Do not touch its pins or hold directly on
any exposed prints.
NOTICE
First place the OLD part in the spare ESD bag, then take out the NEW part of the
ESD bag.
UR20 4 Service Manual
2.Handling ESD-Sensitive Parts
Copyright © 2009–2023 by UniversalRobotsA/S. All rights reserved.

NOTICE
Do not place the ESD-sensitive part on nonconductive material or on metal
tables/surfaces. If you must put down the ESD-sensitive part for any reason, then
first place it into the ESD bag.
NOTICE
Machine covers and metal tables/surfaces are electrical grounds. They increase
the risk of damage because they make a discharge path from your body through
the ESD-sensitive part. (Large metal objects can be discharge paths without being
grounded.)
NOTICE
If passing an ESD-sensitive part to another person, ensure both are wearing ESD
wristband and the ESD wristband is attached to the system grounding point.
NOTICE
Be extra careful in working with ESD-sensitive parts when cold-weather and heating
is used, because low humidity increases static electricity.
Service Manual 5 UR20
2.Handling ESD-Sensitive Parts
Copyright © 2009–2023 by UniversalRobotsA/S. All rights reserved.

3.Recommended Inspection Activities
3.1. Robot Arm
3.1.1. Inspection Plan
The table below is a checklist of the type of inspections recommended by Universal Robots. Per-
form inspections regularly as advised in the table. Any referenced parts found to be in an unac-
ceptable state must be rectified or replaced.
See the following sections for detailed guidance:
•3.1.2. Visual Inspection: Robot armbelow
•4.1. Pre-Use Assessmenton page12
•4.2. Robot Armon page14
Inspection action type Timeframe
Monthly Biannually Annually
1 Check flat rings V ✘
2 Check robot cable V ✘
3 Check robot cable connection V ✘
4 Check Robot Arm mounting bolts *F✘
5 Check Tool mounting bolts *F✘
6 Round Sling F ✘
V = Visual inspection F = Functional inspection *= Must also be checked after heavy collision
3.1.2. Visual Inspection: Robot arm
NOTICE
Using compressed air to clean the robot arm can damage the robot arm com-
ponents.
•Never use compressed air to clean the robot arm.
UR20 6 Service Manual
3.Recommended Inspection Activities
Copyright © 2009–2023 by UniversalRobotsA/S. All rights reserved.

1. Move the Robot Arm to ZERO position, if possible.
2. Turn off and disconnect the power cable from Control Box.
3. Inspect the cable between Control Box and Robot Arm for any damage.
4. Check the base mounting bolts are properly tightened.
5. Check the tool flange bolts are properly tightened.
6. Inspect the flat rings for wear and damage.
•Replace the flat rings if they are worn out or damaged.
Service Manual 7 UR20
3.Recommended Inspection Activities
Copyright © 2009–2023 by UniversalRobotsA/S. All rights reserved.

NOTICE
If any damage is observed on a robot within the warranty period, contact the
distributor where the robot was purchased.
3.1.3. Functional Inspection
Do functional inspections to ensure the robot arm and its screws, bolts and tools are not loose.
Use a correctly calibrated torque wrench and screwdrivers specified into check the screws and
bolts listed in the inspection plan.
For the robot arm mounting bolts specifications, see the Hardware Installation Manual, chapter
Mechanical Interface: Mounting.
3.1.4. Cleaning your robot
Everyday cleaning
You can wipe away any dust/dirt/oil observed on the robot arm and/or Teach Pendant using a
cloth and one of the following cleaning agents: Water, Isopropyl alcohol, 10% Ethanol alcohol or
10% Naphtha. In rare cases, very small amounts of grease can be visible from the joint. This does
not affect the function, use, or lifetime of the joint.
Additional cleaning
Due to the added focus on cleaning your robot, UniversalRobots recommends cleaning with 70%
isopropyl alcohol (rubbing alcohol).
1. Wipe the robot with a hard twisted micro fiber cloth and 70% isopropyl alcohol (rubbing
alcohol).
2. Let the 70% isopropyl alcohol dwell on the robot for 5 minutes, and then clean the robot
using standard cleaning procedure.
DONOTUSEBLEACH. Do not use bleach in any diluted cleaning solution.
3.2. Control Box and Teach Pendant
3.2.1. Inspection Plan
The table below is a checklist of the type of inspections recommended by Universal Robots. Per-
form inspections regularly as advised in the table. Any referenced parts found to be in an unac-
ceptable state must be rectified or replaced.
See the following sections for detailed guidance:
UR20 8 Service Manual
3.Recommended Inspection Activities
Copyright © 2009–2023 by UniversalRobotsA/S. All rights reserved.

•3.2.2. Functional and Safety Inspectionbelow
•3.1.2. Visual Inspection: Robot armon page6
•4.1. Pre-Use Assessmenton page12
•Control Box
Inspection action type Timeframe
Monthly Biannually Annually
1 Check Emergency stop on Teach
Pendant
F✘
2 & 3
Check the 3PE buttons by pressing
them gently.
F✘
Check Backdrive mode F ✘
Check Freedrive mode F ✘
4 Check safety inputs and outputs(if
connected)
F✘
5 Check Teach Pendant cable and con-
nector
V✘
6 Check and clean air filters on Control
Box
V✘
7 Check terminals in Control Box F ✘
8 &9 Check electrical grounding 1< Ω to
Control Box
F✘
Check main power to Control Box F ✘
V = Visual inspection F = Functional inspection
3.2.2. Functional and Safety Inspection
NOTICE
Failure to test robot safety functions regularly can result in loss of functionality.
•Test the robot safety functions monthly to ensure correct function.
To test the Emergency Stop button on the Teach Pendant:
1. Press the Emergency Stop button on the Teach Pendant.
2. Observe the robot stops and shuts off power to the joints.
3. Power on robot again.
Service Manual 9 UR20
3.Recommended Inspection Activities
Copyright © 2009–2023 by UniversalRobotsA/S. All rights reserved.

Freedrive
To test Freedrive:
1. Unmount tool/s or attachment/s or set the TCP/Payload/CoG according to tool
specifications.
2. To move the robot arm in Freedrive:
•On the 3PE Teach Pendant, rapidly light-press, then light-press-and-hold the 3PE but-
ton.
3. Pull/Push the robot to a horizontally elongated position and release.
4. Verify the robot arm can maintain the position without support and without activating
Freedrive.
Backdrive
If the robot arm is close to colliding with something, you can use the Backdrive function to move
the robot arm to a safe position before (re)initializing it.
To test Backdrive:
1. Press ON to enable power. Status changes to Robot Active
2. Press and hold Freedrive. Status changes to Backdrive
3. Move robot as in Freedrive. Joint brakes are released where needed once the Freedrive but-
ton is activated.
The robot arm is “heavy” to move around in Backdrive, so efort is required to move the joints.
NOTICE
Failure to test Backdrive on all joints can lead to loss of functionality.
•You must test Backdrive mode on all joints.
Safety settings
Verify the robot safety settings comply with the robot installation risk assessment.
Additional safety inputs and outputs are still functioning
UR20 10 Service Manual
3.Recommended Inspection Activities
Copyright © 2009–2023 by UniversalRobotsA/S. All rights reserved.

Check which safety inputs and outputs are active and that they can be triggered via PolyScope or
external devices.
Backup data
See section Backup of data
3.2.3. Visual Inspection: Control Box
1. Disconnect the power cable from Control Box.
2. Check the Control Board terminals are properly inserted.Do not ignore loose wires.
3. Check for any dirt/dust inside Control Box. Clean with ESD vacuum cleaner if needed.
NOTICE
Using compressed air to clean the Control Box can cause damage to the Control
Box components.
•Never use compressed air to clean the Control Box.
3.2.4. Cleaning
To clean the Teach Pendant touch screen
Use a mild, industrial cleaning agent without thinning agents or any aggressive additives. Do not
use an abrasive material to wipe down the screen.Universal Robots does not promote a specific
cleaning agent.
To clean the Control Box filters
There is a filter on either side of the Control Box.
1. Gently remove the outer plastic frame, by pulling where the red arrows are shown in the
images below. The frame tilts outward.
2. Remove both filters and use low pressure air to clean them.
If necessary, replace filters.
Service Manual 11 UR20
3.Recommended Inspection Activities
Copyright © 2009–2023 by UniversalRobotsA/S. All rights reserved.

4.Service and Replacement of Parts
4.1. Pre-Use Assessment
The tests and verifications, listed below, must all be conducted before using the robot for the first
time or after any modifications are made.
•Verify all safety inputs and outputs are correctly connected.
•Test all connected safety inputs and outputs, including devices common to multiple
machines or robots, are functioning.
•Test that emergency stop buttons and input stop the robot and engage brakes.
•Test that safeguard input stop the robot motion. If safeguard reset is configured, check that
it needs to be activated before motion can be resumed.
•Examine the initialization screen to test that reduced mode can switch the safety mode to
reduced mode.
•Test that the operational mode switches the operational mode, see icon in top right corner of
user interface.
•Test that the 3-position enabling device must be pressed to enable motion in manual mode
and that the robot is under reduced speed control.
•Test that System Emergency Stop outputs are actually capable of bringing the whole system
to a safe state.
•Test that the system connected to Robot Moving output, Robot Not Stopping output,
Reduced Mode output, or Not Reduced Mode output can actually detect the output changes
Read Section 9 to learn how to pack down and ship the robot and/or spare parts. Packing and Ship-
ping of Robot/Spare Parts
UR20 12 Service Manual
4.Service and Replacement of Parts
Copyright © 2009–2023 by UniversalRobotsA/S. All rights reserved.

4.1.1. Recommended Tools
Robot Arm Control Box UR20 Torque Wrench
Service tools – part no.:
109011
Service tools – part no.:
109011
Service tools – part no.: [TDB]
Dual Robot Calibration tooling
part no.: [TDB]
Cabinet key
(double-bit key)
SD card reader
Service Manual 13 UR20
Copyright © 2009–2023 by UniversalRobotsA/S. All rights reserved.

4.2. Robot Arm
UR20 14 Service Manual
Copyright © 2009–2023 by UniversalRobotsA/S. All rights reserved.

4.2.1. Connection Torque Values
The clamp connection is present between all joint assemblies.
Clamp Size 2.5
Service Manual 15 UR20
Copyright © 2009–2023 by UniversalRobotsA/S. All rights reserved.

Size Thread Head Size Torque Joints
2.5 M5 Hex key 4 5.5 Nm Wrist 1
Wrist 2
Wrist 3
Tool Flange
Clamp Size 4
Size Thread Head Size Torque Joints
4 M6 Hex key 5 7.5 Nm Elbow Joint
Clamp Size 5
Size Thread Head Size Torque Joints
UR20 16 Service Manual
Copyright © 2009–2023 by UniversalRobotsA/S. All rights reserved.

5 M6 Hex key 5 7.5 Nm Base Flange
Base Joint
Shoulder Joint
NOTICE
Click the torque tool a minimum of three times before use, to get the correct
calibrated torque.
4.2.2. Clamp Connection
The following two sections describe how to disassemble and assemble a joint with a clamp con-
nection.
NOTICE
When handling joints, consider the weight of each individual joint and observe the
relevent safety rules.
Joint Size Joint mass
Joint Size 5 15.8 Kg.
Joint Size 4 9.1 Kg.
Joint Size 2.5 2.9 Kg.
Clamp Connection: Disassembly
WARNING
Unsupported joints can fall, or be dropped, resulting in injury.
•Support joints while clamps are being removed.
Service Manual 17 UR20
Copyright © 2009–2023 by UniversalRobotsA/S. All rights reserved.