Bender CMD420 User manual

Manual
EN
CMD420/421
Current monitoring device
for monitoring of 3AC current with current
transformer for overcurrent or undercurrent
or in window mode for overcurrent and under current
Software version CMD420: D287 V1.1x
Software version CMD421: D294 V1.1x
CMD42x_D00101_01_M_XXEN/10.2021

Bender GmbH & Co. KG
Postfach 1161 • 35301 Grünberg • Germany
Londorfer Str. 65 • 35305 Grünberg • Germany
Tel.: [phone] • Fax: [phone]
E-Mail: [e-mail] • www.bender.de
©Bender GmbH & Co. KG
All rights reserved.
Reprinting only with permission of the publisher.
Subject to change!
Photos: Bender archives

3
Table of Contents
CMD42x_D00101_01_M_XXEN/10.2021
1. Important information ................................................................................................ 5
1.1 How to use this manual ................................................................................................. 5
1.2 Technical support: service and support .................................................................. 5
1.3 Training courses ............................................................................................................... 6
1.4 Delivery conditions, warranty and liability ............................................................. 7
1.5 Inspection, transport and storage ............................................................................. 7
1.6 Warranty and liability ..................................................................................................... 7
1.7 Disposal ............................................................................................................................... 8
2. Safety instructions ....................................................................................................... 9
2.1 General safety instructions .......................................................................................... 9
2.2 Work activities on electrical installations ................................................................ 9
2.3 Intended use ..................................................................................................................... 9
3. Function ...................................................................................................................... 11
3.1 Device features ............................................................................................................... 11
3.2 Description of function ............................................................................................... 11
3.2.1 Window discriminator function ........................................................................ 11
3.2.2 Automatic self test ................................................................................................. 12
3.2.3 Manual self test ....................................................................................................... 12
3.2.4 Malfunction .............................................................................................................. 12
3.2.5 Fault memory .......................................................................................................... 12
3.2.6 Setting the number of reload cycles ............................................................... 12
3.2.7 Erasable history memory .................................................................................... 12
3.2.8 Assigning alarm categories to alarm relays K1/K2 ..................................... 13
3.2.9 Delay times t, ton and toff ................................................................................ 13
3.2.10 Password protection (on, OFF) .......................................................................... 13
3.2.11 Factory setting FAC ............................................................................................... 13
3.2.12 Transformation ratio of the current transformers ...................................... 14
4. Installation, connection and commissioning ...................................................... 15
4.1 Installing the device ..................................................................................................... 15
4.2 Connection of the device ........................................................................................... 16
4.3 Commissioning .............................................................................................................. 17
4.4 Factory setting ................................................................................................................ 17
4.5 Maintenance ................................................................................................................... 18

Inhaltsverzeichnis
4CMD42x_D00101_01_M_XXEN/10.2021
5. Operation and configuration .................................................................................. 19
5.1 Display elements in use .............................................................................................. 19
5.2 Function of the operating elements ...................................................................... 20
5.3 Menu structure .............................................................................................................. 21
5.4 Display in standard mode .......................................................................................... 22
5.5 Display in menu mode ................................................................................................ 23
5.5.1 Parameter query and setting: overview ...................................................... 23
5.5.2 Changeover from overcurrent to undercurrent mode or
to window mode ................................................................................................... 25
5.5.3 Response value setting for overcurrent: ....................................................... 26
5.5.4 Setting the fault memory and alarm relay operating mode ................. 27
5.5.5 Assigning alarm categories to the alarm relays ......................................... 28
5.5.6 Setting time delays ............................................................................................... 29
5.5.7 Changing from overcurrent operation to window operation .............. 30
5.5.8 Setting the transformation ratio for external current transformer ..... 31
5.5.9 Factory setting and password protection .................................................... 31
5.5.10 Restore factory setting ........................................................................................ 32
5.5.11 Device information query .................................................................................. 33
5.5.12 History memory query ........................................................................................ 33
6. Technical data ............................................................................................................ 35
6.1 Data in tabular form .................................................................................................... 35
6.2 Standards, approvals and certifications ............................................................... 39
6.3 Label for modified versions ...................................................................................... 39
6.4 Ordering details ............................................................................................................ 39
6.5 Revision history .............................................................................................................40

5
CMD42x_D00101_01_M_XXEN/10.2021
1.Importantinformation
1.1Howtousethismanual
Importantnotesandinformationaremarkedwiththefollowingsymbols.
1.2Technicalsupport:serviceandsupport
ForcommissioningandtroubleshootingBenderoffersyou:
Firstlevelsupport
Technicalsupportbyphoneore-mailforallBenderproducts
•Questionsconcerningspecificcustomerapplications
•Commissioning
•Troubleshooting
Telephone:[phone]*
Fax:[phone]
InGermanyonly:0700BenderHelp(Tel.andFax)
E-mail:[e-mail]
Thismanualisintendedforqualifiedpersonnelworkinginelec-
tricalengineeringandelectronics!
Thissignalwordindicatesthatthereisahighriskofdangerthat
willresultinelectrocutionorseriousinjuryifnotavoided.
Thissignalwordindicatesamediumriskofdangerthatcanlead
todeathorseriousinjuryifnotavoided.
Thissignalwordindicatesalowlevelriskthatcanresultinminor
ormoderateinjuryordamagetopropertyifnotavoided.
Thissymboldenotesinformationintendedtoassisttheuserin
makingoptimumuseoftheproduct.
DANGER
WARNING
CAUTION

Important information
6CMD42x_D00101_01_M_XXEN/10.2021
Repair service
Repair, calibration, update and replacement service for Bender products
•Repairing, calibrating, testing and analysing Bender products
•Hardware and software update for Bender devices
•Delivery of replacement devices for faulty or incorrectly delivered devices
•Extended warranty with in-house repair service or replacement device at no extra cost
Telephone: [phone]** (technical issues)
[phone]**, -785** (sales)
Fax: [phone]
E-mail: [email protected]
Please send the devices for repair to the following address:
Bender GmbH, Repair-Service, Londorfer Str. 65, 35305 Gruenberg
Field service
On-site service for all Bender products
•Commissioning, parameter setting, maintenance, troubleshooting
•Analysis of the electrical installation in the building (power quality test, EMC test,
thermography)
•Practical training courses for customers
Telephone: [phone]**, -762 **(technical issues)
[phone]** (sales)
Fax: [phone]
E-mail: [email protected]
Internet: www.bender-de.com
*Available from 7.00 a.m. to 8.00 p.m. 365 days a year (CET/UTC+1)
**Mo-Thu 7.00 a.m. - 8.00 p.m., Fr 7.00 a.m. - 13.00 p.m
1.3 Training courses
Bender provides training on how to use the universal measuring device.
Current dates of training courses and workshops can be found on the Internet at
http://www.bender.de -> Know-how -> Seminars

Important information
7
CMD42x_D00101_01_M_XXEN/10.2021
1.4 Delivery conditions, warranty and liability
The conditions of sale and delivery set out by Bender GmbH apply.
For software products, the "Softwareklausel zur Überlassung von Standard-Software
als Teil von Lieferungen, Ergänzung und Änderung der Allgemeinen Lieferbedingun-
gen für Erzeugnisse und Leistungen der Elektroindustrie" (software clause in respect
of the licensing of standard software as part of deliveries, modifications and changes
to general delivery conditions for products and services in the electrical industry) set
out by the ZVEI (Zentralverband Elektrotechnik- und Elektronikindustrie e.V., - German
Electrical and Electronic Manufacturers' Association) also applies.
Conditions of sale and delivery can be obtained from Bender in printed or electronic
format.
1.5 Inspection, transport and storage
Inspect the dispatch and equipment packaging for damage, and compare the con-
tents of the package with the delivery documents. In the event of damage in transit,
please contact Bender immediately.
The devices must only be stored in areas where it is protected from dust, humidity and
spray or dripping water, and in which the specified storage temperatures can be as-
sured.
1.6 Warranty and liability
Warranty and liability claims in the event of injury to persons or damage to property
are excluded if they can be attributed to one or more of the following causes:
•Improper use of the device.
•Incorrect mounting, commissioning, operation and maintenance of the device.
•Failure to observe the instructions in this operating manual regarding transport, com-
missioning, operation and maintenance of the device.
•Unauthorised changes to the device made by parties other than the manufacturer.
•Non-observance of technical data.
•Repairs carried out incorrectly and the use of replacement parts or accessories not
approved by the manufacturer.
•Catastrophes caused by external influences and force majeure.
•Mounting and installation with device combinations not recommended by the manu-
facturer.
This operating manual, especially the safety instructions, must be observed by all per-
sonnel working on the device. Furthermore, the rules and regulations that apply for
accident prevention at the place of use must be observed.

Important information
8CMD42x_D00101_01_M_XXEN/10.2021
1.7 Disposal
Abide by the national regulations and laws governing the disposal of this device. Ask
your supplier if you are not sure how to dispose of the old equipment.
The directive on waste electrical and electronic equipment (WEEE directive) and the
directive on the restriction of certain hazardous substances in electrical and electronic
equipment (RoHS directive) apply in the European Community. In Germany, these
policies are implemented through the "Electrical and Electronic Equipment Act" (Ele-
ktroG). According to this, the following applies:
•Electric and electronic equipment are not to be included in household waste.
•Batteries and accumulators are not to be included in household waste but must be
disposed of in accordance with the regulations.
•Old electrical and electronic equipment from users other than private households
which was introduced to the market after 13th August 2005 must be taken back by
the manufacturer and disposed of properly.
For more information on the disposal of Bender devices, refer to our website at
www.bender.de -> Service & support

9
CMD42x_D00101_01_M_XXEN/10.2021
2. Safety instructions
2.1 General safety instructions
Part of the device documentation in addition to this manual is the enclosed "Safety instruc-
tions for Bender products".
2.2 Work activities on electrical installations
If the device is used outside the Federal Republic of Germany, the applicable local
standards and regulations must be complied with.
2.3 Intended use
The current monitoring device CMD420 resp. CMD421 monitors a three-phase system and
also three different AC systems for undercurrent or overcurrent, and in window mode for
undercurrent and overcurrent. For current measurement, three external standard current
transformers are to be connected according to the wiring diagram. The transformation ra-
tio (n = x/1 A resp. n = x/5 A) can be set in the range from 1…2000.
In order to meet the requirements of the applicable standards, customised parameter set-
tings must be made on the equipment in order to adapt it to local equipment and operat-
ing conditions. Please heed the limits of the range of application indicated in the technical
data.
Any use other than that described in this manual is regarded as improper.
Read the operating manual before starting to install, connect
and commission the device. After successful commissioning, keep
the manual within easy reach for future reference.
Only qualified personnel are permitted to carry out the work nec-
essary to install, commission and run a device or system.
DANGER
Risk of fatal injury from electric shock
Touching live parts of the system carries the risk of:
• A fatal electric shock
• Damage to the electrical installation
• Destruction of the device
Before installing the device and before working on the connections of
the device, make sure that the system is de-energised. The rules for
working on electrical systems must be observed.

Safety instructions
10 CMD42x_D00101_01_M_XXEN/10.2021

11
CMD42x_D00101_01_M_XXEN/10.2021
3. Function
3.1 Device features
•Undercurrent and overcurrent monitoring in AC systems, current
monitoring with window discriminator function
•Current monitoring using standard current transformers:
x/ 1A (CMD420), x/ 5A (CMD421)
•Two separately adjustable alarm relays with one changeover contact each (K1, K2)
•Fault memory behaviour for the alarm relays selectable
•N/C or N/O operation selectable for K1, K2
•Digital measured value display via multi-functional LC display
•LEDs: Power On (ON), Alarm 1 (AL1) and Alarm 2 (AL2)
•Start-up delay, response delay and delay on release
•Adjustable switching hysteresis
•r.m.s. value measurement AC
•History memory for the operating value
•Cyclical self test
•Test and reset button
•Password protection to prevent unauthorised changes being made to device settings
•Sealable transparent cover
•Available with screw-type or push-wire terminals
3.2 Description of function
Once the supply voltage is applied, the start-up delay begins. Measured values changing
during this time do not influence the switching state of the alarm relays.
The devices provide two separately adjustable response values (overcurrent/undercurrent).
When the measuring quantity exceeds the response value ("Alarm 2") or falls below the re-
sponse value ("Alarm 1"), such as is the case with window discriminator function, the time of
the response delays "ton1/2" begins. When the response delay has elapsed, the alarm relays
switch and the alarm LEDs light. If the measured value falls below or exceeds the release
value (response value plus hysteresis) after the alarm relays have switched, the pre-defined
delay on release starts "toff". Once "toff" has elapsed, the alarm relays switch back to their ini-
tial position. With the fault memory activated, the alarm relays do not change their actual
state until the reset button R is pressed.
3.2.1 Window discriminator function
This operating mode can be used to monitor the measured current for two response values,
overcurrent and undercurrent.
This operating mode (In) can be selected from the SEt menu.

Function
12 CMD42x_D00101_01_M_XXEN/10.2021
Changing the operating mode of the current monitoring device, overcurrent mode (Hi), un-
dercurrent mode (Lo) or window mode (In) changes the meaning of the alarm LEDs AL1 and
AL2:
3.2.2 Automatic self test
The device automatically carries out a self test after connecting to the system to be moni-
tored and later every 24 hours. During the self test internal functional faults will be detected
and appear in form of an error code on the display. The alarm relays are not switched during
this test.
3.2.3 Manual self test
After pressing the test button for > 1.5 s, the device carries out a self test. During this test,
internal functional faults are detected and will be displayed in form of an error code. The
alarm relays and LEDs are checked during this test.
While holding down the test button "T", all device-relevant display elements appear on the
display.
3.2.4 Malfunction
In the event of an internal malfunction, all three LEDs will flash. The error code (E01…E32)
will appear on the display. In such a case please contact the Bender Service.
3.2.5 Fault memory
The fault memory can be activated, deactivated or set to continuous mode (con). If the fault
memory is set to "con“ mode, the alarm parameters remain stored even on failure of the sup-
ply voltage.
3.2.6 Setting the number of reload cycles
If faults occur only temporarily, but recurrently, in the system being monitored, with the fault
memory M deactivated, the alarm relays would switch synchronously to the error status.
RL in the out menu can be used to limit the number of these changeover processes. As soon
as the preset number of switching cycles is exceeded, the fault memory will come on and an
activated alarm remains stored.
3.2.7 Erasable history memory
The first alarm value to occur is written to this memory. The memory can be erased via the
HiS menu.
Communication mode LED lights Meaning
HI AL1 Prewarning overcurrent (>I)
AL2 Alarm overcurrent (>I)
Lo AL1 Prewarning undercurrent (<I)
AL2 Alarm undercurrent (<I)
In AL1 Alarm undercurrent (<I)
AL2 Alarm overcurrent (>I)

Function
13
CMD42x_D00101_01_M_XXEN/10.2021
3.2.8 Assigning alarm categories to alarm relays K1/K2
Different alarm categories can be assigned to the alarm relays K1/K2 via the menu "out".
3.2.9 Delay times t, ton and toff
The times t, ton and toff, described below, delay the output of alarms via LEDs and relays.
Start-up delay t
After connection to the supply voltage, the alarm indication is delayed by the preset time
t (0…300 s).
Response delay ton1/2
If the response value is exceeded or not reached, the current monitoring device requires
the response time tan until an alarm is signalled.
A set response delay ton1/2 (0…300 s) adds up to the device-related operating time tae and
delays alarm signalling (total delay time tan = tae + ton).
Should the fault no longer persist during the response delay, the alarm signal drops out.
Delay on release toff
If the alarm no longer exists during the response delay and the fault memory is deactivated,
the alarm LEDs will go out and the alarm relays switch back to their initial position. After
activating the release delay (0…300 s), the alarm state is continuously maintained for the
selected period.
3.2.10 Password protection (on, OFF)
With the password protection activated (on), settings can only be made subject to the cor-
rect password being entered (0…999).
3.2.11 Factory setting FAC
After activating the factory setting, all previously changed settings are reset to delivery sta-
tus.
Alarm indication of system-related failures (e.g. supply voltage not
available) or a device error, requires at least one of the alarm re-
lays, K1 or K2, to be in N/C operation mode (n.c.). In addition, the
alarm category "Err" has to be assigned to the selected alarm relay
in the menu out/r1 or r2.
If these conditions cannot be met, periodic inspection of the
CMD420/CMD421 is required!
CAUTION

Function
14 CMD42x_D00101_01_M_XXEN/10.2021
3.2.12 Transformation ratio of the current transformers
The transformation ratio for the current transformers has to be set as factor nin the menu
"Set".
The CMD420 requires current transformers with a transformation ratio of
n= x/1A.
The CMD421 requires current transformers with a transformation ratio of
n= x/5A.
The actual primary current can be calculated by multiplying the measured current by factor
nand indicated on the display.
In addition, the set factor ndirectly affects the minimum and maximum adjustable re-
sponse value thresholds in the alarm menu. The factor is the multiplier of the nominal re-
sponse range!
Adjustable response value thresholds = nominal response range x factor n
If the calculation of the adjustable response value results in a value of more than three
digits, the first three digits indicated are not rounded.
The resolution of the adjustable response range is calculated as follows:
Resolution of setting = factor n/ 100
Transformation ratio
Resolution of the display
Factor nResolution of the settings
1…9 1 0.01 A
10…99 1 00.1 A
100…990 10 001 A
1.00…2.00 k 0.05 k 0.01 kA
Factor n
Response value range CMD420
min. max.
1…9 0.10…1.00 A 0.90…9.00 A
10…99 1.0…10.0 A 9.90…99.0 A
100…990 10…100 A 99.0…990 A
1.00…2.00 k 0.10…1.00 kA 0.20…2.00 kA
Factor n
Response value range CMD421
min. max.
1…9 0.50…5.00 A 4.50…45.0 A
10…99 5.0…50.0 A 49.5…495 A
100…990 50…500 A 495 A…4.95 kA
1.00…2.00 k 0.50…5.00 kA 1.00…10.0 kA

15
CMD42x_D00101_01_M_XXEN/10.2021
4. Installation, connection and commissioning
4.1 Installing the device
Fig. 4.1: Dimension diagram and drawing for screw fixing
Mounting on DIN rail:
Snap the rear mounting clip of the device into place in such a way that a safe and tight fit
is ensured.
Screw fixing:
Use the tool to move the rear mounting clips (a second. mounting clip is required, see or-
dering information) to a position that it projects beyond the enclosure. Then fix the device
using two M4 screws.
Only qualified personnel are permitted to carry out the work nec-
essary to install, commission and run a device or system.
Risk of electrocution due to electric shock!
Touching live parts of the system carries the risk of:
• An electric shock
• Damage to the electrical installation
• Destruction of the device
Before installing and connecting the device, make sure that
the installation has been de-energised. Observe the rules for
working on electrical installations.
DANGER
100 mm
116 mm
Zubehör/
Accessory
90 mm
45
67,5
36 mm
31,1
47,5
70,5
2
2

Installation, connection and commissioning
16 CMD42x_D00101_01_M_XXEN/10.2021
4.2 Connection of the device
Connect the device according the wiring diagram.
Us
A1
~/–
~/+
6A 6A
IT-System
A2
k1
11 1412
21 2422
A2A1
L1
N
L2
L3
l3k3
l1 k2
l2
k1 l1
k2 l2
k3 l3
1
2
3
Connect the conductor to the push-
wire terminals according to the
schematic diagram.
Terminal Connections
A1, A2 Connection to supply volt-
age Us
k1, l1
k2, l2
k3, l3
Connection to the conduc-
tors to be monitored using
current transformers
11, 12, 14 Alarm relay K1
21, 22, 24 Alarm relay K2

Installation, connection and commissioning
17
CMD42x_D00101_01_M_XXEN/10.2021
4.3 Commissioning
Checks must be carried out prior to commissioning to ensure that the current monitoring
device has been connected correctly. Then perform a functional test.
4.4 Factory setting
Incorrect connections can lead to personal injury and damage to
equipment or property!
The maximum permissible measuring current and the overload
capability of the measuring inputs k, l have to be taken into con-
sideration!
CMD420
Response value overcurrent I1 (prewarning)
Response value overcurrent I2 (alarm)
CMD421
Response value overcurrent I1 (prewarning)
Response value overcurrent I2 (alarm)
CMD420 / CMD421
Hysteresis:
Fault memory M:
Operating mode K1/K2
Reload cycles
Alarm assignment K1
Alarm assignment K2
Response delay:
Start-up delay:
Delay on release:
Monitoring function:
Transformation ratio n
Password:
0.15 A (50 % of I2)
0.30 A
0.75 A (50 % of I2)
1.50 A
15 %
activated (on)
N/C operation (n.c.)
0
Error (Err), response value I1, manual test
(tES)
Error (Err), response value I2, manual test
(tES)
ton1 = 1 s
ton2 = 0 s
t = 0.5 s
toff = 1 s
Overcurrent (HI)
1
0, deactivated (Off)
CAUTION

Installation, connection and commissioning
18 CMD42x_D00101_01_M_XXEN/10.2021
4.5 Maintenance
A functional test is recommended to be carried out at regular intervals. It is preferable to
check correct alarm indication by means of a current fault.
Also check that the terminal connections are mechanically secure.
One alarm relay of the CMD420 CMD421 must work in N/C opera-
tion with the alarm category "Err" assigned to this relay, otherwise
periodic inspection will be necessary!
CAUTION

19
CMD42x_D00101_01_M_XXEN/10.2021
5. Operation and configuration
5.1 Operating elements
Device front Element Mode
ON Power On LED, green
AL1
AL2
LED Alarm 1 lit up (yellow):
Response value 1 reached
LED Alarm 2 lit up (yellow): Response value 2 reached
T
Up button (< 1.5 s):
Menu items/values
Test button (> 1.5 s):
to indicate the display elements in use,
to start a self test;
R
Down button (< 1.5 s):
Menu items/value
Reset button (> 1.5 s):
Deactivating the fault memory;
MENU
MENU button (> 1.5 s):
To start the menu mode;
Enter button (< 1.5 s):
To confirm menu item, submenu item and value.
Enter button (> 1.5 s):
Move to the next higher menu level (back)

Operation and configuration
20 CMD42x_D00101_01_M_XXEN/10.2021
5.2 Display elements in use
Display elements in use Element Mode
L1, L2, L3 Values of the measurement inputs k1/l1,
k2/l2, k3/l3
RL Reload function with memory = off (L = I.)
nTransformation ratio for external current
transformer
< I12
> I12
Undercurrent I1 or I2
Overcurrent I1 or I2
r1, 1
r2, 2
Alarm relay K1,
Alarm relay K2
I Hys %,
Hys
Response value hysteresis in %;
Hys in standard mode: Measured value in
the hysteresis range according to alarm
ton1,
ton2,
T,
toff
Response delay ton1 (K1),
Response delay ton2 (K2)
Start-up delay t
Delay on release toff for K1, K2
MFault memory active
Operating mode for relays K1, K2
Password protection enabled
M
H
y
s
offont
A
m
k
s
2
1
n
.
l
R
L3
L2L1
>
>