Bender CMD421 User manual

Manual
EN
CMD420
CMD421
Current monitoring device
for monitoring of 3AC current with current transformer for
overcurrent or undercurrent
or in window mode for overcurrent and undercurrent
Software version CMD420: D287 V1.1x
Software version CMD421: D294 V1.1x
CMD420-421_D00101_M_XXEN/07.2016

Bender GmbH & Co. KG
P.O. Box 1161 • 35301 Gruenberg • Germany
Londorfer Strasse 65 • 35305 Gruenberg • Germany
Tel.: [phone] • Fax: [phone]
E-Mail: [email protected] • www.bender.de
©Bender GmbH & Co. KG
All rights reserved.
Reprinting only with permission of the publisher.
Subject to change!
Photos: Bender archives

Table of Contents
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CMD420-421_D00101_M_XXEN/07.2016
1. Important information .................................................................................... 7
1.1 How to use this manual ................................................................................. 7
1.2 Technical support: service and support ................................................... 8
1.2.1 First level support ............................................................................................. 8
1.2.2 Repair service ..................................................................................................... 8
1.2.3 Field service ........................................................................................................ 9
1.3 Training courses ............................................................................................. 10
1.4 Delivery conditions ....................................................................................... 10
1.5 Inspection, transport and storage ........................................................... 10
1.6 Warranty and liability ................................................................................... 11
1.7 Disposal ............................................................................................................ 12
2. Safety instructions ......................................................................................... 13
2.1 General safety instructions ........................................................................ 13
2.2 Work activities on electrical installations ............................................. 13
2.3 Intended use ................................................................................................... 14
2.4 Information about factory setting .......................................................... 14
3. Function ........................................................................................................... 15
3.1 Device features .............................................................................................. 15
3.2 Description of function ............................................................................... 15
3.2.1 Window discriminator function ............................................................... 16
3.2.2 Automatic self test ........................................................................................ 17
3.2.3 Manual self test .............................................................................................. 17
3.2.4 Malfunction ..................................................................................................... 17
3.2.5 Fault memory ................................................................................................. 17
3.2.6 Setting the number of reload cycles ...................................................... 17
3.2.7 Erasable history memory ............................................................................ 17
3.2.8 Assigning alarm categories to alarm relays K1/K2 ............................ 18

Table of Contents
4CMD420-421_D00101_M_XXEN/07.2016
3.2.9 Delay times t, ton and toff ........................................................................ 18
3.2.10 Password protection (on, OFF) ................................................................. 19
3.2.11 Factory setting FAC ...................................................................................... 19
3.2.12 Transformation ratio of the current transformers ............................. 19
4. Installation, connection and commissioning ........................................... 21
4.1 Installing the device ..................................................................................... 22
4.2 Connection of the device ........................................................................... 23
4.3 Commissioning .............................................................................................. 24
4.4 Factory setting ................................................................................................ 25
4.5 Maintenance ................................................................................................... 25
5. Operation and configuration ...................................................................... 27
5.1 Display elements in use .............................................................................. 27
5.2 Function of the operating elements ...................................................... 28
5.3 Menu structure ............................................................................................... 29
5.4 Display in standard mode .......................................................................... 31
5.5 Display in menu mode ................................................................................ 32
5.5.1 Parameter query and setting: overview ............................................... 32
5.5.2 Changeover from overcurrent to undercurrent mode or to window
mode .................................................................................................................. 34
5.5.3 Response value setting for overcurrent: ............................................... 35
5.5.4 Setting the fault memory and alarm relay operating mode .......... 36
5.5.5 Assigning alarm categories to the alarm relays ................................. 37
5.5.6 Setting time delays ....................................................................................... 39
5.5.7 Changing from overcurrent operation to window operation ...... 40
5.5.8 Setting the transformation ratio for external current transformer ...
40
5.5.9 Factory setting and password protection ............................................ 41
5.5.10 Restoring factory settings .......................................................................... 42
5.5.11 Device information query .......................................................................... 43
5.5.12 History memory query ................................................................................. 43

Table of Contents
5CMD420-421_D00101_M_XXEN/07.2016
6. Technical data ................................................................................................ 45
6.1 Data in tabular form ..................................................................................... 45
6.2 Standards, approvals and certifications ................................................ 49
6.3 Label for modified versions ....................................................................... 49
6.4 Ordering details ............................................................................................. 50

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CMD420-421_D00101_M_XXEN/07.2016
1. Important information
1.1 How to use this manual
Always keep this manual within easy reach for future reference.
To make it easier for you to understand and revisit certain sections in this man-
ual, we have used symbols to identify important instructions and information.
The meaning of these symbols is explained below:
This manual is intended for qualified personnel working in
electrical engineering and electronics!
This signal word indicates that there is a high risk of danger
that will result in electrocution or serious injury if not
avoided.
This signal word indicates a medium risk of danger that
can lead to death or serious injury if not avoided.
This signal word indicates a low level risk that can result in
minor or moderate injury or damage to property if not
avoided.
This symbol denotes information intended to assist the user
in making optimum use of the product.
DANGER
WARNING
CAUTION

Important information
8CMD420-421_D00101_M_XXEN/07.2016
This manual has been compiled with great care. It might nevertheless contain
errors and mistakes. Bender cannot accept any liability for injury to persons or
damage to property resulting from errors or mistakes in this manual.
1.2 Technical support: service and support
For commissioning and troubleshooting Bender offers you:
1.2.1 First level support
Technical support by phone or e-mail for all Bender products
 Questions concerning specific customer applications
 Commissioning
 Troubleshooting
Telephone:
Fax:
In Germany only:
E-mail:
[phone]*
[phone]
0700BenderHelp (Tel. and Fax)
[e-mail]
1.2.2 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 in the event of faulty or incorrectly
delivered Bender devices
 Extended guarantee for Bender devices, which includes an in-house
repair service or replacement devices at no extra cost
Telephone:
Fax:
E-mail:
[phone]** (technical
issues)
[phone]**, -785** (sales)
[phone]
[e-mail]
Please send the devices for repair to the following address:

Important information
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CMD420-421_D00101_M_XXEN/07.2016
Bender GmbH, Repair-Service,
Londorfer Str. 65,
35305 Gruenberg
1.2.3 Field service
On-site service for all Bender products
 Commissioning, configuring, maintenance, troubleshooting of Bender
products
 Analysis of the electrical installation in the building (power quality test,
EMC test, thermography)
 Training courses for customers
Telephone:
Fax:
E-mail:
Internet:
[phone]**, -762 **(technical issues)
[phone]** (sales)
[phone]
[e-mail]
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

Important information
10 CMD420-421_D00101_M_XXEN/07.2016
1.3 Training courses
Bender is happy to provide training regarding the use of test equipment.
The dates of training courses and workshops can be found on the Internet at
www.bender-de.com -> Know-how -> Seminars.
1.4 Delivery conditions
Bender sale and delivery conditions apply.
For software products the "Softwareklausel zur Überlassung von Standard-
Software als Teil von Lieferungen, Ergänzung und Änderung der Allgemeinen
Lieferbedingungen für Erzeugnisse und Leistungen der Elektroindustrie"
(software clause in respect of the licensing of standard software as part of de-
liveries, modifications and changes to general delivery conditions for prod-
ucts and services in the electrical industry) set out by the ZVEI (Zentralverband
Elektrotechnik- und Elektronikindustrie e. V.) (German Electrical and Electron-
ic Manufacturer's Association) also applies.
Sale and delivery conditions can be obtained from Bender in printed or elec-
tronic format.
1.5 Inspection, transport and storage
Inspect the dispatch and equipment packaging for damage, and compare the
contents 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 they are protected from dust,
damp, and spray and dripping water, and in which the specified storage tem-
peratures can be ensured.

Important information
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CMD420-421_D00101_M_XXEN/07.2016
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 follow-
ing 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, commissioning, 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 recom-
mended by the manufacturer.
This operating manual, especially the safety instructions,
must be observed by all personnel working on the device. Furthermore,
the rules and regulations that apply for accident prevention at the place of use
must be observed.

Important information
12 CMD420-421_D00101_M_XXEN/07.2016
1.7 Disposal
Abide by the national regulations and laws governing the disposal of this de-
vice. Ask your supplier if you are not sure how to dispose of the old equip-
ment.
The directive on waste electrical and electronic equipment (WEEE directive)
and the directive on the restriction of certain hazardous substances in electri-
cal and electronic equipment (RoHS directive) apply in the European Commu-
nity. In Germany, these policies are implemented through the "Electrical and
Electronic Equipment Act" (ElektroG). According to this, the following applies:
 Electrical and electronic equipment are not part of household waste.
 Batteries and accumulators are not part of household waste and 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 13 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
homepage at www.bender-de.com -> Service & support.

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CMD420-421_D00101_M_XXEN/07.2016
2. Safety instructions
2.1 General safety instructions
Part of the device documentation in addition to this manual is the enclosed
"Safety instructions 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. The European stand-
ard EN 50110 can be used as a guide.
Only qualified personnel are permitted to carry out the
work necessary 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

Safety instructions
14 CMD420-421_D00101_M_XXEN/07.2016
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 over-
current, and in window mode for undercurrent and overcurrent. For current
measurement, three external standard current transformers are to be con-
nected according to the wiring diagram. The transformation ratio (n = x/1A
resp. n = x/5A) can be set in the range from 1…2000.
In order to meet the requirements of the applicable standards, customised pa-
rameter settings must be made on the equipment in order to adapt it to local
equipment and operating 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.
2.4 Information about factory setting
Page25 provides a summary of all factory settings.
For resetting the current monitor to its factory settings refer to page 42.

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CMD420-421_D00101_M_XXEN/07.2016
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 val-
ues changing during this time do not influence the switching state of the
alarm relays.

Function
16 CMD420-421_D00101_M_XXEN/07.2016
The devices provide two separately adjustable response values (overcurrent/
undercurrent). When the measuring quantity exceeds the response value
("Alarm 2") or falls below the response 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 initial 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 re-
sponse values, overcurrent and undercurrent.
This operating mode (In) can be selected from the SEt menu.
Changing the operating mode of the current monitoring device, overcurrent
mode (Hi), undercurrent mode (Lo) or window mode (In) changes the mean-
ing of the alarm LEDs AL1 and AL2:
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
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CMD420-421_D00101_M_XXEN/07.2016
3.2.2 Automatic self test
The device automatically carries out a self test after connecting to the system
to be monitored and later every 24 hours. During the self test internal func-
tional faults will be detected and appear in form of an error code on the dis-
play. 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. Dur-
ing 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 Bend-
er 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 supply voltage.
3.2.6 Setting the number of reload cycles
If faults occur only temporarily, but recurrently, in the system being moni-
tored, 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 proc-
esses. 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.

Function
18 CMD420-421_D00101_M_XXEN/07.2016
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 de-
vice 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.
Alarm indication of system-related failures (e.g. supply
voltage not available) or a device error, requires at least one
of the alarm relays, 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
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CMD420-421_D00101_M_XXEN/07.2016
3.2.10 Password protection (on, OFF)
With the password protection activated (on), settings can only be made sub-
ject to the correct password being entered (0…999).
3.2.11 Factory setting FAC
After activating the factory setting, all previously changed settings are reset to
delivery status.
3.2.12 Transformation ratio of the current transformers
The transformation ratio for the current transformers has to be set as factor n
in 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 ad-
justable response value thresholds in the alarm menu. The factor is the multi-
plier of the nominal response range!
Adjustable response value thresholds = nominal response range x factor n
Transformation ratio Resolution
of the
display
Factor n
Resolution
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

Function
20 CMD420-421_D00101_M_XXEN/07.2016
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
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