AEMC 5050 User manual

MEGOHMMETER 5050
5060
User ManualENGLISH

Copyright © Chauvin Arnoux®, Inc. d.b.a. AEMC®Instruments. All rights reserved.
No part of this documentation may be reproduced in any form or by any means (including electronic
storage and retrieval or translation into any other language) without prior agreement and written consent
from Chauvin Arnoux®, Inc., as governed by United States and International copyright laws.
Chauvin Arnoux®, Inc. d.b.a. AEMC®Instruments
15 Faraday Drive • Dover, NH 03820 USA
Tel: [phone] or [phone] • Fax: [phone]
This documentation is provided “as is,” without warranty of any kind, express, implied, or otherwise.
Chauvin Arnoux®󰀨
but does not warrant the accuracy or completeness of the text, graphics, or other information contained
in this documentation. Chauvin Arnoux®, Inc. shall not be liable for any damages, special, indirect,


user of the documentation has been advised of the possibility of such damages.

Statement of Compliance
Chauvin Arnoux®, Inc. d.b.a. AEMC® Instruments
certifies that this instrument has been calibrated using
standards and instruments traceable to international
standards.
We guarantee that at the time of shipping your
instrument has met its published specifications.
An NIST traceable certificate may be requested at
the time of purchase, or obtained by returning the
instrument to our repair and calibration facility, for
a nominal charge.
The recommended calibration interval for this
instrument is 12 months and begins on the date of
receipt by the customer. For recalibration, please
use our calibration services. Refer to our repair and
calibration section at www.aemc.com.
Serial #:
Catalog #: 2130.20 / 2130.21
Model #: 5050 / 5060
Please fill in the appropriate date as indicated:
Date Received:
Date Calibration Due:
Chauvin Arnoux®, Inc.
d.b.a AEMC®Instruments
www.aemc.com

TABLE OF CONTENTS
1. INTRODUCTION ................................................................................ 6
1.1 PRECAUTIONS FOR USE........................................................ 7
1.2 RECEIVING YOUR SHIPMENT................................................ 7
1.3 ORDERING INFORMATION ..................................................... 7
1.3.1 Accessories and Replacement Parts .............................................8
1.4 ACCESSORY INFORMATION .................................................. 8
1.4.1 DataView®Software (for Model 5060)............................................8
2. PRODUCT FEATURES...................................................................... 9
2.1 DESCRIPTION ........................................................................... 9
2.1.1 Model 5050 ..................................................................................10
2.1.2 Model 5060 ..................................................................................10
2.2 MEGOHMETER FEATURES................................................... 11
2.3 DIGITAL FEATURES................................................................ 12
2.4 BARGRAPH.............................................................................. 12
2.5 SYMBOLS................................................................................. 13
2.6 PUSH-BUTTON FUNCTIONS................................................. 13
2.6.1 2nd Button .....................................................................................13
2.6.2 V-TIME / Button......................................................................14
2.6.3 R-DAR-PI-DD / R(t) Button ..........................................................15
2.6.4 / ALARM Button .....................................................................19
.......................................................................20
2.6.6 Button......................................................................................20
2.6.7 SET-UP Function .........................................................................21
2.6.8 Clearing the Memory....................................................................23
2.6.9 Communication Rate (USB Port) .................................................23
 .....................................................23
2.6.11 Voltage Disturbance Limit...........................................................23
2.6.12 Automatic Measuring Range......................................................24
2.6.13 Blocking (Disabling) Test Voltages .............................................25
3. MEASUREMENT FUNCTIONS....................................................... 26
3.1 AC/DC VOLTAGE ..................................................................... 26
3.2 INSULATION MEASUREMENT .............................................. 26

4. OPERATION ..................................................................................... 28
4.1 MEASUREMENT PROCEDURE............................................. 28
4.2 INSULATION MEASUREMENT .............................................. 28
4.3 OPERATION EXAMPLES........................................................ 29
4.4 CAPACITANCE MEASUREMENT .......................................... 30
4.5 RESIDUAL AND LEAKAGE CURRENT MEASUREMENT... 30
5. MEMORY / USB PORT (5060)......................................................... 31
5.1 USB PORT SPECIFICATIONS ............................................... 31
5.2 SAVING / RECALLING VALUES (MEM/MR BUTTON) ......... 31
5.3 PRINTING MEASURED VALUES........................................... 33
5.4 INSTANTANEOUS PRINTING OF MEASUREMENTS ......... 33
5.5 PRINTING DATA IN MEMORY (PRINT MEM BUTTON)....... 34
6. DATAVIEW®....................................................................................... 35
6.1 INSTALLING DATAVIEW®....................................................... 35
6.2 MEGOHMMETER CONTROL PANEL .................................... 37
7. SPECIFICATIONS............................................................................ 38
7.1 REFERENCE CONDITIONS................................................... 38
7.2 VOLTAGE.................................................................................. 38
7.3 INSULATION RESISTANCE ................................................... 38
7.4 POWER SUPPLY ..................................................................... 43
7.5 ENVIRONMENTAL SPECIFICATIONS .................................. 44
7.6 MECHANICAL SPECIFICATIONS.......................................... 44
7.7 SAFETY SPECIFICATIONS.................................................... 44
7.8 VARIATIONS IN OPERATING RANGE .................................. 45
8. MAINTENANCE................................................................................ 46
8.1 RECHARGING THE BATTERY............................................... 46
8.2 FUSE REPLACEMENT............................................................ 46
8.3 CLEANING................................................................................ 46
8.4 STORAGE................................................................................. 47
8.5 REPAIR AND CALIBRATION .................................................. 47
8.6 TECHNICAL AND SALES ASSISTANCE ............................... 47
8.7 LIMITED WARRANTY.............................................................. 48
8.8 WARRANTY REPAIRS ............................................................ 48

6 Megohmmeter Models 5050 & 5060
1. INTRODUCTION
Thank you for purchasing a Megohmmeter Model 5050 or 5060.
For best results from your instrument and for your safety, read the enclosed
operating instructions carefully and comply with the precautions for use. These

Symbols
Instrument is protected by double or reinforced insulation.
CAUTION - DANGER! Read the User Manual.
Risk of electric shock. The voltage at the parts marked with this
symbol may be dangerous.


regarding Low-Voltage Safety, Electromagnetic Compatibility, and
the Restriction of Hazardous Substances.
The trash can with a line through it means that in the European
Union, the product must undergo selective disposal for the recycling
of electric and electronic material in compliance with Directive
WEEE 2002/96/EC.

CAT IV corresponds to measurements taken at the primary electrical supply
(<1000V).
Example: primary overcurrent protection devices, ripple control units, and meters.
CAT III corresponds to measurements taken in building installations at the
distribution level.
Example: distribution panel, circuit-breakers, machines, and xed industrial
devices.
CAT II corresponds to measurements taken on circuits directly connected to
low-voltage installations.
Example: power supple to domestic electrical appliances and portable tools

Megohmmeter Models 5050 & 5060 7
1.1 PRECAUTIONS FOR USE
These safety warnings are provided to ensure the safety of personnel and proper
operation of the instrument.
■Do not attempt to perform any tests with these instruments until you have read
the instruction manual.
■Safety is the responsibility of the operator!
■Tests are to be carried out only on non-energized circuits! Check for live
circuits before making resistance measurements (safety check).
■High voltage is present, as is the sample connected to it. Anyone performing
or assisting in testing must follow all safety precautions to prevent electrical
shock to themselves and others.
■Use personal protective equipment where appropriate.
■When testing samples with a capacitive component, make sure they have
been properly discharged and are safe to touch. Dielectric insulation samples

energized.
■Megohmmeters should never be used in an explosive environment.
■Only use the leads that are supplied with the megohmmeter. If they are
defective or worn, replace before testing.
■This instrument can be used on installations rated for 1000V, Category III.
1.2 RECEIVING YOUR SHIPMENT
■Match the contents with the ordering information.
■Notify your distributor of any missing items.
■
carrier and notify your distributor at once.
NOTE: Fully charge the instrument before use.
1.3 ORDERING INFORMATION
Megohmmeter Model 5050............................................................. Cat. #2130.20
Includes extra large classic tool bag, set of three 10 ft (5kV) safety leads (red/
black/blue) with clips, one guard terminal jumper lead, US 115V power cord,
rechargeable battery pack, and user manual.
Megohmmeter Model 5060............................................................. Cat. #2130.21
Includes extra large tool bag, set of three 10 ft (5kV) safety leads (red/black/blue)
with clips, one guard terminal jumper lead, US power cord, rechargeable battery
pack, USB A-B cable, USB stick with DataView®software, and user manual.

8 Megohmmeter Models 5050 & 5060

Cable, PC RS-232, DB9 F/F 6 ft Null Modem Cable
(For meters without USB port)...........................................................Cat. #2119.45
Fuse, Set of 3, 0.1A, 380V, 5 x 20, .10kA..........................................Cat. #2119.84
Extra Large Classic Tool Bag ........................................................... Cat. #2133.73
Inverter – 12VDC to 120VAC 200 Watt for Vehicle use.................... Cat. #2135.43
Cable – 10 ft USB Cable .................................................................. Cat. #2136.80
Cable - 5 ft USB A-B Cable .............................................................. Cat. #2140.46
Lead – Replacement set of 3, 10 ft (5kV) Color-coded Safety
with Clips (JUMPER LEAD NOT INCLUDED).................................. Cat. #2151.30
Lead – Replacement 1 ft Jumper Lead ............................................ Cat. #2151.31
Lead – Set of 3, 25 ft (5kV) Safety with Clips................................... Cat. #2151.32
Battery – Rechargeable 9.6V ........................................................... Cat. #2960.21
US 115V Power Cord ....................................................................... Cat. #5000.14
Megohmmeter Calibration Checker.................................................. Cat. #5000.66
1.4 ACCESSORY INFORMATION
®
Dataview®software makes it possible to:
■Retrieve data from memory and plot graphs of the changes in insulation as a
function of the time over which the test voltage is applied, R(t).
■Print out protocols of personalized tests depending on the user’s needs.
■
■Set up and control the instrument entirely by the USB serial port.

Check our Storefront at www.aemc.com/store for availability

Megohmmeter Models 5050 & 5060 9
2. PRODUCT FEATURES
2.1 DESCRIPTION
The Megohmmeter Models 5050 and 5060 are portable instruments that are
housed in rugged casing.
These megohmmeters are designed to check the safety of electrical installations
and equipment.
Measures:
■Voltage.
■Insulation Resistance.
■Capacitance.
■Leakage Current.
Advantages:
■Automatic voltage detection in all functions, before or during the
measurement, which inhibits or stops the measurement.
■Automatic detection of external AC or DC voltages on the terminals.
■Threshold programming in each function to trigger audible alarms.
■Timed control of measurement duration.
■Fuse protection with defective fuse detection and indication.
■
■Automatic discharge of residual high voltage on the tested device.
■󰀨
■Battery level indicator.
■Large, easy-to-read, and back-lit LCD.

■128kB memory, real-time clock, and USB serial port.
■Control and programming of the instrument from a PC (with DataView®
software) for download, report, and printing.

10 Megohmmeter Models 5050 & 5060
2.1.1 Model 5050
2.1.2 Model 5060
( )
FF 0.1A
380V - 10kA
5x20mm
110 - 230V
50/60 Hz
20 VA max
CALIBRATION
2
nd
SMOOTHALARM
R(t)
MEGOHMMETER
MODEL 5050
R-DAR-PI-DD
V/TIME
START/STOP
1000V CAT III
2500V
G
OFF
MΩ-1000V
MΩ- 2500V
MΩ- 5000V
MΩ 50-5000V
SET-UP
MΩ- 500V
1
6
7
5
32 4

Megohmmeter Models 5050 & 5060 11
2.2 MEGOHMETER FEATURES
1. Safety terminals: “+”, “G”, and “-” and access to the protective fuse.
2. AC power plug (direct operation on AC and battery recharge).
3. Back-lit liquid crystal display.
4. Serial interface.
• Male plug 9 pin for calibration only (Model 5050).
• USB port for connection to a PC (Model 5060).
5. Rotary selector switch with 7 positions:
• OFF󰀨
• MΩ- 500V - Insulation measurement (to 2TΩ).
• MΩ- 1000V -Insulation measurement (to 4TΩ).
• MΩ- 2500V - Insulation measurement (to 10TΩ).
• MΩ- 5000V - Insulation measurement (to 10TΩ).
• MΩ- 50V-5000V - Insulation measurement with selectable test voltage.
• SET-UP - Set-up of the megohmmeter.
6. START/STOP button.
7.  
The second functions are highlighted in yellow below each button:
• 2nd  - Selects the second function on each button.
• R-DAR-PI-DD - Lets you choose the type of measurement to be
performed. Instantaneous Resistance (R), Dielectric Absorption (DAR),
Polarization Index (PI), or Dielectric Discharge (DD).
• R(t) - Shows/hides the interval values of insulation resistance, test voltage
and time-stamping, following a time-controlled test.
• V/TIME - When measuring insulation, pressing this button displays
the time elapsed since the beginning of the measurement, then the
exact voltage generated. When performing resistance or capacitance
󰀨
the date and time at which the measurement was stored, the exact test
voltage and the OBJ : TEST number.
• - Activates or deactivates the “time-controlled” test mode.
• - Turns the display backlight ON or OFF.
• ALARM - Activates or deactivates the alarms programmed in SET-UP.
• 
• SMOOTH - Stops/starts smoothing of displayed values during insulation
testing.
• 
list of interval insulation measurements, in the R(t) function.

12 Megohmmeter Models 5050 & 5060
• 
list of interval insulation measurements in the R(t) function.
  
parameters is increased to a faster rate.
Model 5060 only:
• MEM - Saves measured values.
• MR - Recalls saved data.
• PRINT MEM - Prints memory contents.
• Printing measurement data is completed through DataView®software.
2.3 DIGITAL FEATURES
8.8.8.8
0
.
1
M
1
M
1
0
M
1
0
0
M
1
G
1
0
G
1
0
0
G
1
T
µA nA µF
COM
P
GΩ
PI
DARDD
ALARM
TΩ
MΩkΩ
MEM MR
SMOOTH REMOTE
OBJ.
min sec
TEST
V
DC
AC
2nd
8.8.8.8

Indicates the value of:
• Insulation measurement (resistance, DAR and PI, DD, capacitance).

Indicates:
• Voltage measured or applied by the instrument.
• Elapsed time or the output voltage, during insulation measurement.
After recording a set of data (5060), the small display also indicates the time and
date in MR (memory recall) mode, and the memory address with the OBJ : TEST
number.
2.4 BARGRAPH
■Active during insulation measurement (0.1MΩto 1TΩ).
■Indicates the battery charge at start-up.
■Indicates free memory space. One segment represents approximately 100
groups of saved values with each group holding approximately 50 recordings
(1 OBJ and 1 TEST).

Megohmmeter Models 5050 & 5060 13
2.5 SYMBOLS
MEM/MR: Memory address (5060) - indicates the memory operation.
OBJ:TEST: Memory address (5060) - the number is displayed on the small
digital display.
COM: Flashes on the screen when data is transmitted to the serial interface
(5060) or remains permanently displayed if there is a problem during transfer.
DAR/PI/DD: Indicates the mode chosen before insulation measurement or the
results of these measurements.
 
Indicates external voltage present, symbol is activated after pressing
 .
Activation of “time-controlled test” mode or clock adjustment when in
SET-UP (5060).
(Yellow button) Selects the second (bottom) function of a button.
Flashes if the battery voltage is low to indicate that the battery should
be recharged (see §8.1). The voltage is displayed on the small display
for 2 seconds when the instrument is turned on. The main display
indicates “bat” when the test is carried on.
Warning buzzer is activated.
 󰀨
SMOOTH: Smooths the insulation measurements displayed.
REMOTE: Remote control via an interface (5060). In this mode, all the buttons
and the rotary switch on the instrument are non-functional except for the OFF
position.
FUSE -G-: Flashes if the “G” input fuse is defective.
2.6 PUSH-BUTTON FUNCTIONS
2.6.1 2nd Button
■Selects the second function (highlighted in yellow) of the buttons.
■The symbol appears. This symbol will disappear upon pressing the

disappears when the button is pressed again or if other function buttons

button without having to press the button every time.

14 Megohmmeter Models 5050 & 5060
2.6.2 V-TIME / Button

Displays all the secondary information available on the small display.

■The time elapsed since the start of the measurement.
■The voltage between the instrument’s “+” and “–” terminals.
■Date, time, test voltage and OBJ:TEST number in memory recall mode (MR).
 
Displays the measurement duration programmed in SET-UP on the small display.
■The symbol lights up.
■Pressing the START button begins the measurement process. The
measurement duration is set to 15 minutes by default.
■As soon as the measurement starts, the small display counts down
the remaining duration of the measurement. Once it reaches zero, the
measurement stops.
■As the time-controlled test is carried out, interval samples (resistance/voltage
values as a function of time) are automatically saved. The time between each
sample is set to 30s by default, but it can be changed in the SET-UP menu.
■The samples are displayed with the R(t) function (see §2.6.3) as long as a
new measurement has not been started. With each new measurement, the
previous sample value is erased from the memory. These sample values are
saved with the last value of the resistance if used with the MEM (memory
storage) function.
NOTE: If the selector switch’s position is altered or if the STOP button
is pressed during measurement, the measurement will be interrupted.
This function is only active for insulation measurement.

Megohmmeter Models 5050 & 5060 15
2.6.3 R-DAR-PI-DD / R(t) Button

The R-DAR-PI-DD button allows automatic measurement of:
■Dielectric Absorption Ratio (DAR).
■Polarization Index (PI).
■Dielectric Discharge Test (DD).
The PI and DAR values are useful on long cables or when monitoring aging
insulation on electrical machines.
󰀨
interfering currents (from capacitive charges, dielectric absorption), which
eventually cancel each other out. In order to get an accurate measurement of the
leakage current, it is necessary to perform the measurement over a long period

measurement.
Then, the PI or the DAR ratios are calculated:
■PI* = R10 min / R1 min (2 values recorded during a 10-minute measurement).
■DAR = R1 min / R30 s (2 values recorded during a 1-minute measurement).
The quality of insulation depends on the results found.
DAR PI 
< 1.25 < 1 Inadequate, even dangerous
< 2
< 1.6  Good
  Excellent
*The 10 and 1 minute times can be modied in the SET-UP menu, to adapt to any changes
or specic applications.
If one layer is defective but all the others show strong resistance for multi-layer
󰀩
of problem.
Therefore, a dielectric discharge test (DD) is necessary to supplement the PI and
DAR indications.
This test measures the dielectric absorption of heterogeneous or multi-layer
insulation while ignoring the parallel-surface leak currents.
󰀩
the insulation to be measured (a typical value is the application of a 500V voltage
for 30 minutes).
The test voltage is chosen in the same way as the insulation measurement in the
SET-UP menu. The device will cause a fast discharge during which the insulation
capacity is measured and measured again 1 minute after the residual current is
circulating in the insulation.

16 Megohmmeter Models 5050 & 5060
The DD value is calculated from the formula below:
DD= current measured after 1 minute (mA)
test voltage (V) x capacity measured (F)
The indication of the insulation quality as a function of the resulting value is as
follows:
DD value 
 Very bad
 Bad
 Doubtful
DD <2 Good insulation
NOTE: The dielectric discharge test is suited for the insulation
measurement of rotating machines and for the insulation measurement
of heterogeneous or multilayer insulation containing organic materials
in general.

During or after measurement, the R-DAR-PI-DD button allows you to scroll
through the following values:
■
■
■DD can only be calculated 1 minute after the end of the insulation
measurement and circuit discharge, and only if it was selected before
beginning the measurement.
■Capacitance in µF (only after the measurement has stopped and the circuit
has been discharged).
■Residual leakage current circulating in the installation in µA or nA.
■
NOTE: During the measurement, the DAR value is not available if
the DD value was preselected before the measurement. The PI value
is not available if DAR or DD values were preselected before the
measurement.

Megohmmeter Models 5050 & 5060 17

If the R-DAR-PI-DD button is pressed during the voltage measurement before
the start of a measurement, the following will be displayed:
NOTE: The input current may be a depolarization current resulting from
an earlier insulation measurement. It is recommended to start a new DAR
and PI measurement after the current has dropped to a negligible value
(on the order of 100pA) to avoid variations on these measurements.
Depending on the choices (DAR or PI), the measurement will go as follows:
a) DAR: Press START - the DAR 
“- - - -” as long as the calculation of the ratio is not possible (t <1 mn).
e.g.:
DAR
After 1 min, the measurement will stop and the main display will automatically
show the DAR value. During or after measurement, the R-DAR-PI-DD button can
be used to see the insulation measurement carried out, but it does not give the PI
value since the measurement has not lasted long enough.
b) PI: Press START - the PI
long as the calculation of the ratio is not possible (t < programmed PI times).
e.g.:
PI
After the upper PI time has passed, the measurement stops and the main display
automatically shows the PI value. During and after measurement, the R-DAR-
PI-DD button makes it possible to display the DAR (after 1 min), the PI, and the
insulation measurement.
c) DD: Press START - the DD 
“- - - -” as long as the calculation of the ratio is not possible (t <30 min +1
min).
e.g.:
DD
1 minute after the measurement stops, the DD symbol will become steady, and
the display will automatically show the value of DD.
Therefore: if the measurement lasts 1 min - DAR.
if the measurement lasts longer than the programmed PI time - PI.
if 1 min. after the end of the measurement - DD.
MΩ DAR PI DD

18 Megohmmeter Models 5050 & 5060
NOTE: If during DAR or PI measurement (automatic or not), a high
external interference voltage becomes present, or the insulation
resistance goes beyond the device’s measurement range. Then, the
DAR or PI measurements are interrupted and the screen indicates:
DAR or MΩPI MΩor DD MΩ
The display of the DD value is:
■Unknown (- - - -) if C < 1nF and Idd < 100pA.
■
■
(with C = measured capacitance and Idd = measured leakage current).
NOTE: The 10 min / 1 min measurement durations for PI calculation
SET-UP menu (see §2.6.7), which allows
changes to standards or to suit a particular application.

Used to access the interval insulation resistance values as a function of time after
a measurement in “time-controlled test” mode (see §2.6.2).
The time between each saved sample is programmed in the SET-UP menu.
This function is also available on the Model 5050, which has neither a read-write
memory for saving measured data, nor an interface for data retrieval from the
instrument by a PC.
Model 5050:
Up to 20 samples can be recorded during measurement at the sample rate
chosen in SET-UP (the default value is 30 seconds). It is possible to save more
than 20 samples depending on available memory.
Model 5060:
The number of saved samples is limited only by the memory space available.
To enter the display mode, press the R(t) button:
■The small display indicates the time 00:30 (e.g. the sampling frequency is
every 30s).
■The main display shows the corresponding R value.
Use the V/TIME button to alternate between the voltage and time (on the small
display) associated with the R value on the main display.
The button is used to scroll down through the all the samples saved during
measurement, which allows you to read the information in order to draw R(t) and
V(t) graphs.
This makes it possible to carry out R(t) analysis on-site without a printer or a PC.
To exit this function, press the R(t) or R-DAR-PI-DD button again.

Megohmmeter Models 5050 & 5060 19
2.6.4 / ALARM Button

Turns the display back-light ON or OFF.

Activates/deactivates the ALARM function. The “ALARM” symbol is displayed
when activated.
If activated and the high or low threshold values are programmed, the “ALARM”

threshold is crossed.
󰀨
󰀨
ACTIVATING THE ALARM INDICATION BEFORE A TEST
To activate the Alarm Indication before performing a test you must go through the
following steps:
■Program the Alarm Set Point Resistance Value for the Test Voltage that you
will use.
■Turn the Rotary switch to the Setup position.
■Press the Yellow 2nd button. Then, press the Alarm button to set Alarms. The

■Press the 2nd & Alarm buttons repeatedly until you see the test in the top line
of the display that you wish to set alarms for. The sequencing will be 500,
1000, 2500, 5000, and set.
■

■

selection.
■Press the Right Arrow Key again to move to the Resistance Value Set Point
Selection. You can change this value digit by digit using the Up Arrow / Left
Arrow combination working from the highest to lowest digit.
■
desired test function.
■Before initiating a test, press the Yellow 2nd button and the Alarm button to

side of the display.
■Next, press the round yellow Start/Stop button to begin the test. The Alarm

is tripped.

20 Megohmmeter Models 5050 & 5060
NOTE:󰀨
nd


is desired.
2.6.5 / Smooth Button


 button (see §2.6.6).

󰀨
displayed values (which are smoothed) and not the actual measurements.
For example, this function is useful when the displayed insulation values are
highly unstable, brought about due to a capacitive component in the tested
element.
2.6.6 Button





the following low or high limit).

■
■Press button for a longer time to increase at a faster rate.

■
■Press button for a longer time to decrease at a faster rate.
Unlike all the second functions of other buttons, it is not necessary to press the
 symbol remains displayed

pressing or another button.