Mitsubishi Electric MDU-BN User manual

Securely insert the connection cable into the MDU connector (until the lock clicks into place). The product will be unable to measure
properly if the connection is poor.
Some models/specifications do not measure or display some items. These items and functions will be skipped.
Connector
MDUMDU Breaker main unit Connection cable
Caution
Caution
Danger
Indications and what they mean are listed below.
Wrong handling may cause dangerous situation in which possibility of fatal accidents or serious injuries assumed.
Wrong handling may cause dangerous situation in which possibility of significant or minor injuries, or material damages assumed.
INSTRUCTION MANUAL
MDU BREAKER: MDU
TYPE
MDU-BN, MDU-BP, MDU-BC, MDU-BM
MODEL
NF250-SEV with MDU, NF250-HEV with MDU
NF400-SEW with MDU, NF400-HEW with MDU
NF800-SEW with MDU, NF800-HEW with MDU
Using this under certain conditions may cause electrical shock.
●Read this Instruction Manual carefully prior to use, so that the product is used properly.
●After reading this manual, store it in a safe place so that it can be easily referenced when needed.
●Make sure that the end user receives this Instruction Manual.
For models with CC-Link communication, refer to the PLC User’s Manual before reading this Instruction Manual.
• CC-Link System Master/Local Module User’s Manual
* The CC-Link version is “CC-Link Ver. 1.10.”

1
1. Safety Precautions ………………………………………………………………………………………………………… 3
2. Precautions for Use ………………………………………………………………………………………………………… 3
2.1 Standard operating conditions ……………………………………………………………………………………… 3
2.2 Withstand voltage test………………………………………………………………………………………………… 4
2.3 Connection and installation ………………………………………………………………………………………… 5
2.4 Requests………………………………………………………………………………………………………………… 6
2.5 Notes on usage………………………………………………………………………………………………………… 6
3. MDU Breaker Installation Instructions …………………………………………………………………………………… 7
3.1 MDU mounting (external mounting for 250 A frame) …………………………………………………………… 7
3.1.1 Check the wiring of the connection cable ………………………………………………………………… 7
3.1.2 Mounting of MDU mounting plate (Figure 2 and 3) …………………………………………………… 7
3.1.3 Mounting of MDU to MDU Breaker main unit …………………………………………………………… 8
3.2 MDU mounting (external mounting for 400/800 A frame) ……………………………………………………… 9
3.2.1 Mounting of MDU mounting plate ………………………………………………………………………… 9
3.2.2 Mounting of MDU to MDU Breaker main unit ………………………………………………………… 10
3.3 MDU mounting (panel mounting)………………………………………………………………………………… 11
3.3.1 No transmission, electric energy pulse output………………………………………………………… 11
3.3.2 With CC-Link communication/MODBUS communication…………………………………………… 13
3.4 Wiring of MDU terminal block …………………………………………………………………………………… 14
3.4.1 External mounting type …………………………………………………………………………………… 14
3.4.2 Panel mounting type ……………………………………………………………………………………… 14
4. MDU Features and Functions ………………………………………………………………………………………… 16
4.1 Features of MDU …………………………………………………………………………………………………… 16
4.2 Functions of MDU…………………………………………………………………………………………………… 16
4.3 Measurement functions …………………………………………………………………………………………… 17
4.3.1 Measurement function list ………………………………………………………………………………… 17
4.3.2 Measurement rated values/measurement range and accuracy …………………………………… 18
4.4 Monitoring functions ……………………………………………………………………………………………… 22
4.4.1 Monitoring function list …………………………………………………………………………………… 22
4.5 How to use monitoring functions ………………………………………………………………………………… 23
4.5.1 MDU Breaker alarms ……………………………………………………………………………………… 23
4.5.2 MDU Breaker status ……………………………………………………………………………………… 25
4.5.3 Fault causes ………………………………………………………………………………………………… 25
4.5.4 Electric current demand upper/lower limit alarms …………………………………………………… 25
4.5.5 Neutral line open phase alarm (NLA) ………………………………………………………………… 25
4.6 Network Specifications for MDU ………………………………………………………………………………… 26
4.6.1 Electric energy pulse output ……………………………………………………………………………… 26
4.6.2 CC-Link communication ………………………………………………………………………………… 26
4.6.3 MODBUS communication ………………………………………………………………………………… 26
■Table of Contents

2
5. Names and Functions of MDU Parts ………………………………………………………………………………… 27
5.1 Display/operation panel …………………………………………………………………………………………… 27
5.2 MDU terminal block section ……………………………………………………………………………………… 28
5.3 CC-Link setting area (with CC-Link communication option)………………………………………………… 29
5.4 Number of CC-Link communication connectable units and precautions ………………………………… 30
5.5 Installation and wiring for products with CC-Link communication ………………………………………… 31
5.5.1 Terminator installation …………………………………………………………………………………… 31
5.5.2 Shielded wire grounding ………………………………………………………………………………… 31
5.6 MODBUS setting area (with MODBUS communication option) …………………………………………… 32
5.7 Installation and wiring for products with MODBUS communication ……………………………………… 33
6. MDU Detailed Specifications …………………………………………………………………………………………… 34
6.1 Precautions for measurement …………………………………………………………………………………… 34
7. MDU Operation Procedure ……………………………………………………………………………………………… 36
7.1 Operating method for main menu screen ……………………………………………………………………… 37
7.1.1 Display method for protection characteristic setting values ……………………………………… 38
7.1.1-1 Protection characteristic setting and setting method for 250 A frame ………………… 38
7.1.1-2 Protection characteristic setting and setting method for 400/800 A frame …………… 39
7.1.2 Method for various settings ……………………………………………………………………………… 40
7.1.2-1 Setting method for measurement-related items …………………………………………… 40
7.1.2-2 Setting method for alarms ……………………………………………………………………… 42
7.1.2-3 Setting method for LCD ………………………………………………………………………… 44
7.1.2-4 Setting method for date and time …………………………………………………………… 46
7.1.2-5 Setting method for electric energy …………………………………………………………… 47
7.1.2-6 Setting method for measurement items …………………………………………………… 48
7.1.2-7 Setting method for free display ……………………………………………………………… 49
7.1.3 Method for resetting alarms ……………………………………………………………………………… 50
7.1.4 Method for resetting fault cause/current, maximum value, electric energy,
and reactive energy ……………………………………………………………………………………… 50
7.1.5 Method for displaying information screen……………………………………………………………… 51
7.2 Operating method for measurement display screen ………………………………………………………… 52
7.2.1 Switching method for display screen …………………………………………………………………… 52
7.2.2 Measurement display list ………………………………………………………………………………… 53
7.2.3 Fault/alarm display details ……………………………………………………………………………… 57
8. Appendix ………………………………………………………………………………………………………………… 58
8.1 Precautions for setting operation ………………………………………………………………………………… 58
8.2 Precautions when setting via CC-Link communication/MODBUS communication …………………… 58
8.3 Communication error codes and solutions …………………………………………………………………… 59
8.4 Troubleshooting …………………………………………………………………………………………………… 59

3
1. Safety Precautions
This Instruction Manual is meant mainly for those with specialized electrical knowledge who will use this product to manufacture assembled products,
perform electrical work, or conduct maintenance and inspections. This also includes those who will operate this product (the end user).
2. Precautions for Use
Unless otherwise noted, the following terms in this Instruction Manual indicate the models shown below.
2.1 Standard operating conditions
●The standard operating conditions are described below. Be sure to use MDU Breaker within these conditions.
[1] Operating ambient temperature: -10°C to +40°C (must not exceed an average of +35°C within a 24 hour period)
[2] Ambient storage temperature: -25°C to +55°C (no condensation/freezing)
[3] Relative operating/storage humidity: 85% RH or less (no condensation)
[4] Altitude: 2,000 m or lower
[5] Operating/storage atmosphere: Must contain hardly any dust, smoke, corrosive gas, combustible gas, moisture, salt, etc.
●If the ambient temperature of MDU Breaker exceeds +40°C, use with a decreasing continuous load current.
Ambient temperature of +50°C: 0.9 times, ambient temperature of +60°C: 0.7 times
●Do not install in abnormal environments subject to high temperature, high humidity, dust, corrosive gas, vibration, impact, etc. Doing so may
cause electrical shock, fire, or may cause the product to stop working.
●Do not wipe the MDU Breaker main unit or MDU with thinner, detergent, or chemical cloth.
Doing so may fade printing, reduce insulation performance, or cause mold to form. Clean with air or by brushing.
●The case of the MDU may become discolored depending on the environment. However, this will not have any effect on performance.
●The LCD may have bright (always on) or dark (always off) pixels due to the characteristics of LCDs.
Because LCDs contain many display elements, there is no way to ensure that bright or dark pixels will never occur. Bright or dark pixels are not
defects in the product itself.
●The screen on the LCD may flicker due to the internal processing for refreshing, but this is not a trouble of the main body.
Caution
Molded Case Circuit Breaker (MCCB)NF400-SEW with MDU,
NF400-HEW with MDU
NF800-SEW with MDU,
NF800-HEW with MDU
400 A frame
NF250-SEV with MDU,
NF250-HEV with MDU
250 A frame 800 A frame
●When installing or removing MDU Breaker main unit and a Measuring Display Unit (MDU), first turn the host circuit breaker OFF and confirm that
no electricity is flowing.
●This product must be handled by someone with specialized knowledge.
Caution

4
2.2 Withstand voltage test
●When conducting a MDU terminal test, always connect the MDU Breaker main unit and MDU.
●A voltage measurement transformer is connected between poles on the load side of the MDU Breaker main unit.
In the table below, ×indicates that, because it causes a failure, withstand voltage test between poles on the load side must not be performed.
In the table below, △indicates that, although nothing broke during a 500 VDC insulation resistance test, there was a low insulation resistance value.
No problems found during withstand voltage test and insulation resistance test conducted on entire main circuit and between ground on MDU
Breaker main unit.
●When checking DA, DB, DG, 485+, 485-, Ter, SLD, and FG terminal conductivity for models with CC-Link communication/MODBUS communication,
do not allow the voltage between each terminal to reach 5 VDC or higher.
Doing so may cause failure.
*1. Test with MDU terminals (L1, L2, 114, 113, DA, DB, DG, 485+, 485-, Ter, SLD, FG) as ground side.
*2. Test with MDU terminals (114, 113, DA, DB, DG, 485+, 485-, Ter, SLD, FG) as ground side.
*3. Do not perform a withstand voltage test between MDU terminals (DA, DB, DG, SLD) and MDU terminal (FG).
*4. MDU terminals (DA, DB, DG, SLD, FG) must always be tested together.
*5. Do not perform a withstand voltage test between MDU terminals (485+, 485-, Ter, SLD) and MDU terminal (FG).
*6. MDU terminals (485+, 485-, Ter, SLD, FG) must always be tested together.
Measurement point/test
Between MDU terminals (L1, L2) and MDU terminals (DA, DB, DG, SLD, FG) (with CC-Link
communication) (*3) (*4)
Insulation resistance
measurement
ON OFF
Withstand voltage test
ON OFF Test conditions
〇 〇
〇 〇
〇 〇
〇 〇
〇 〇
〇 〇
〇 〇
〇
〇
〇
〇
〇△
△
△
△
△
△
△ △
△△
△△
〇
〇
〇
〇
〇
〇
〇
〇
〇
〇
〇
〇
×
×
×
×
〇
〇
Between MDU terminals (L1, L2) and MDU terminals (485+, 485-, Ter, SLD, FG)
(with MODBUS communication) (*5) (*6) 〇 〇 〇〇
〇
〇
〇
〇 〇 〇〇
〇
〇
×
×
×
×
×
×
×
×
––
Status of handle
Between live part and ground
Between main circuit and MDU terminals (L1, L2, FG)
Between power supply and load terminal
Between main circuit and MDU terminals (114, 113, FG) (with electric energy pulse output)
Between main circuit and MDU terminals (DA, DB, DG, SLD, FG) (with CC-Link
communication) (*4)
Between main circuit and MDU terminals (485+, 485-, Ter, SLD, FG) (with MODBUS
communication) (*6)
Between MDU terminals (L1, L2) and MDU terminal (FG)
Between MDU terminals (L1, L2) and MDU terminals (114, 113, FG) (with electric energy
pulse output)
Between different
poles
Line side
Load side
Between left and middle poles
Between middle and right poles
Between left and right poles
Between left and neutral poles,
Between middle and neutral poles,
Between right and neutral poles
(for a four-poles circuit breaker)
Between left and middle poles
Between middle and right poles
Between left and right poles
Between left and neutral poles,
Between middle and neutral poles,
Between right and neutral poles
(for a four-poles circuit breaker)
2500 VAC
1 min.
2500 VAC
1 min. (*1)
1500 VAC
1 min. (*2)
Caution

5
2.3 Connection and installation
●MDU Breaker cannot be used with the power side and load side reversed.
●Do not forcefully pull the connection cable between the MDU and MDU Breaker main unit (15 N or less). Doing so may loosen or disconnect
the cable.
●When installed to the MDU, if the MDU Breaker main unit cuts off a fault current and must be replaced with a new unit, also replace
the MDU. It cannot be reused.
●The connection cable between the MDU and MDU Breaker main unit forms a small-signal circuit. Install it at least 10 cm away from strong circuits.
Use with the area around the connector fixed in place, so that no external forces are applied to the connector connection area when opening/
closing the front door. When bending the cable, maintain a radius of at least 20 mm.
●The connector area used to connect to the MDU is insulated from the inside of the MDU Breaker main unit. The product will operate normally and
will not break even if the MDU Breaker main unit is powered with the connector area disconnected (open).
●If a MDU will be installed later, do so within 1.5 years from installing the MDU Breaker main unit.
●Do not insert and pull out cables from the connector area more than 20 times each on the MDU Breaker main unit and MDU.
●Pulling out the connection cable connector when MDU control power is applied may cause a MDU alarm or the like to be erroneously displayed.
If this happens, reset the alarm and clear the memory when pulling out the connector and starting use.
●Control power is required for the MDU. Apply the control power supply voltage shown on the MDU between the L1 and L2 terminals.
Measurement, display, electric energy pulse output, CC-Link communication, and MODBUS communication cannot be used without power.
Install a short-circuit protector (using a circuit breaker or fuse) to the control circuit.
●If using MDU Breaker with a single-phase two-wire circuit, connect it as shown in Figure 1. The left pole (1-phase) load side is a live part,
so be sure to insulate it.
Use the middle pole (2-phase) and the right pole (3-phase) current, and two voltage between the middle pole (2-phase) and the right pole (3-phase)
as measurement data.
Ignore the left pole (1-phase) current, as well as the voltage between the left pole (1-phase) and the middle pole (2-phase) and between the right
pole (3-phase) and the left pole (1-phase).
●If using MDU Breaker with a single-phase three-wire circuit, connect it as shown in Figure 2 below with the neutral line connected to the middle
pole (2-phase).
If the neutral line is connected to either the left pole (1-phase) or the right pole (3-phase), it will be impossible to measure with MDU.
●MDU breaker can not be attached closely.
Secure a 30 mm wiring space on the right side of the circuit breaker and mount the main unit for wiring of the connection cable and installation of
the connector for the connection cable.
●When installing the MDU in a box such as a switchboard or control panel, be careful of the ambient temperature.
Operating ambient temperature: Use within the range of -10°C to +40°C (however, the average value for 24 hours should not exceed +35°C).
If this condition is violated, it may lead to malfunction or loss of lifespan.
Figure 1. Connection method in a single-phase
two-wire circuit
Caution: Live part Load
Load side
Line side
Load side
Line side
Figure 2. Connection method in a single-phase
three-wire circuit
●Note that a three-pole MDU Breaker product cannot be used with a three-phase four-wire system.
The following table shows the items that can be measured when a three-pole product is used with a three-phase four-wire system.
Measurement item
Load current
1 2 3 1 2
200 V
100 V 100 V
3
Line voltage
Harmonic current
Electric power/
reactive power
Electric energy/
reactive energy
Power factor
○Voltage phase, ×N phase
○Voltage phase, ×N phase
○Between voltage phases,
×Between voltage phase and N phase
No CT on N phase, so measurement not possible
No VT between N phases, so measurement not possible
Status Reason
No CT on N phase, so measurement not possible
No CT on N phase and no VT between N phases, so N phase not added
No CT on N phase and no VT between N phases, so N phase not added
No CT on N phase and no VT between N phases, so N phase not included
Caution
A connecting wire of
5.5 mm2or longer is
recommended on
the primary side.
×
×
×

6
2.4 Requests
●The free warranty period and warranty scope for this product are as follows.
●Free warranty period
The free warranty period lasts for one year from the time of purchase.
●Warranty scope
(1) Any failures that occur during the warranty period will be repaired free of charge, assuming that the usage status, usage method, usage
environment, etc. are as described in the product’s catalog, Instruction Manual, warning labels, etc., and that the product was used under standard
conditions as described in the precautions, etc.
However, the free warranty period shall last a maximum of 18 months after manufacture, with a maximum of six months for the distribution period
after the product is shipped from Mitsubishi Electric.
(2) A fee will be charged for repairs under the following circumstances, even if the product is still within the free warranty period.
• Failures resulting from inappropriate storage/handling, carelessness, error, etc. on the customer’s part.
• Failures resulting from installation mistakes.
• Failures resulting from misuse or unreasonable modification.
• Failures resulting from fires, abnormal voltage, or other external events beyond human control, or from earthquakes, wind disasters, or other
natural disasters.
• Failures resulting from phenomena that could not be foreseen using the scientific technology standards at the time the product was shipped by
Mitsubishi Electric.
The free warranty described here applies only to the delivered product, and does not apply to any damage or the like caused by failures in the
delivered product.
●This free warranty does not apply to any damage or the like caused due to reprinting or reproducing the information included in this document
in whole or in part in any form without the consent of Mitsubishi Electric.
●All efforts have been made to keep the information in this document current as software and hardware is revised. However, there may be cases
where inconsistencies arise.
2.5 Notes on usage
(1) The products described in this User’s Manual were designed and manufactured as general-purpose items meant for general industrial use, etc.
Please contact Mitsubishi Electric sales to discuss use for special purposes including atomic energy, electric power, aerospace, medical, or
passenger transport devices or systems.
(2) Mitsubishi Electric shall not be held responsible for damage caused for reasons not attributable to Mitsubishi Electric; opportunities or profit lost by
customers caused by Mitsubishi Electric product failure; damage caused from extraordinary circumstances, secondary damage, accident
compensation, damage to anything other than Mitsubishi Electric products, or compensation for any other work, whether foreseen or not by
Mitsubishi Electric.

7
3. MDU Breaker Installation Instructions
●When mounting or removing the MDU, first turn the host circuit breaker OFF and confirm that no electricity is flowing.
●First set the MDU Breaker main unit to OFF or TRIP, and then mount the MDU and connection cable.
(1) Check that the connection cable is drawn out through the cable outlet port of the MDU Breaker without catching. (Figure 1)
3.1 MDU Mounting (external mounting for 250 A frame)
3.1.1 Check the wiring of the connection cable
(1) Before mounting of MDU mounting plate, connect the terminals on the load side of the breaker.
(2) While pressing the MDU mounting plate to the pressing area of the MDU Breaker main unit, screw the MDU mounting plate into the MDU
Breaker main unit.
Use the included “3×10” screws.
(3) Ground (class D) the FG terminal.
3.1.2 Mounting of MDU mounting plate (Figure 2 and 3)
Cable outlet port
(Figure 1)
FG terminal screw
M4×6
(tightening torque:
1.4 to 1.8 N·m)
Fixing screws for
MDU mounting
plate 3×10
(tightening torque:
1.0 to 1.1 N·m)
MDU mounting plate
(Figure 2)
Pressing area
FG terminal screw
M4×6
(tightening torque:
1.4 to 1.8 N·m)
Fixing screws for
MDU mounting
plate 3×10
(tightening torque:
1.0 to 1.1 N·m)
MDU mounting plate
Pressing area
Fitting
(one place)
Connection
cable
Guide area
Fitting (one place)
Connection cable
Guide area
(Figure 3)
Caution

8
(1) Ground (class D) the FG terminal on the MDU mounting plate.
(2) Securely insert the connection cable coming out from the MDU Breaker main unit into the MDU connector (until the lock clicks into place).
(Figure 4)
(3) Hook the small tab on the back of the MDU onto the fitting on the MDU mounting plate. (Figure 5)
(4) Remove the MDU terminal cover, and then screw it to the MDU mounting plate. (Figure 6)
Use the included “M3×25” fixing screw for MDU.
Arrange the connection cable through the guide area. (Figure 7)
3.1.3 Mounting of MDU to MDU Breaker main unit
<Connecting the connector> (Figure 4)
Click!
View of MDU from the back
Insert
straight
[1] Insert the connector into the MDU connector with the lock area
of the connector to the top.
MDU connector Connector Connection cable
[2] Insert until you hear it
click into place.
Fixing screw for MDU
M3×25
(tightening torque:
0.6 to 0.8 N·m)
(Figure 6)(Figure 5)
Termimal cover
<Mounting/removing the terminal cover>
While pushing the arrow area, use the
area A as a fulcrum and pull it upward.
* When removing the MDU from the MDU Breaker main unit, do it in a reverse procedure to the mounting procedure.
The terminal cover is removable, so use caution when handling it. (Figure 8)
(Figure 7) (Figure 8)
Area A
Arrow area
Terminal cover
Connection cable
Guide area
● Take note of the connector’s orientation and insert it straight.
● Insert until you feel the lock click into place.
Caution
Make sure that the MDU connection cable is not caught by the plate.
Caution
Do not forcefully pull the connection cable. Doing so may result in a disconnection of the cable.
Caution
MDU
connector

9
(1) Screw the MDU mounting plate into the MDU Breaker main unit. (Figures 9, 10)
Use the included “M4×8”screws.
(Figure 9) (Figure 10)
FG terminal screw
M4×6
(tightening torque:
1.4 to 1.8 N·m)
FG terminal screw
M4×6
(tightening torque:
1.4 to 1.8 N·m)
Fixing screws for
MDU mounting
plate M4×8
(tightening torque:
1.4 to 1.8 N·m)
Fixing screws for
MDU mounting
plate M4×8
(tightening torque:
1.4 to 1.8 N·m)
MDU Breaker main unit
(400 A frame)
MDU mounting
plate
MDU mounting plate
Fitting
(one each)
MDU Breaker
main unit
(800 A frame)
3.2 MDU mounting (external mounting for 400/800 A frame)
3.2.1 Mounting of MDU mounting plate
Caution Make sure that the connection cable is not caught and damaged between the MDU mounting plate and MDU.

10
MDU
Connector
Small tab
Hook the small tab on
the MDU on the fitting
on the mounting plate.
(Figure 12)
MDU mounting plate
3.2.2 Mounting of MDU to MDU Breaker main unit
(1) Ground (class D) the FG terminal on the MDU mounting plate.
(2) Securely insert the connection cable coming out from the MDU Breaker main unit into the MDU connector (until the lock clicks into place).
(Figure 11)
<Connecting the connector> (Figure 11)
(Figure 13)
Terminal cover
Fixing screw for MDU
M3×26 (tightening torque: 0.6 to 0.8 N·m)
View of MDU from the back[1] Insert the connector into the MDU connector
with the lock area of the connector to the top.
(3) Hook the small tab on the back of the MDU on the fitting (1)
on the MDU mounting plate. (Figure 12)
Caution
●Take note of the connector’s orientation and insert it straight.
●Insert until you feel the lock click into place.
[2] Insert until you hear it
click into place.
<Mounting/removing the terminal cover>
Area A
Arrow area
While pushing the arrow area, use area A
as a fulcrum and pull it upward.
(Figure 14)
Terminal cover
Terminal cover
(4) Remove the MDU terminal cover, and then screw the MDU mounting plate. (Figure 13 & Figure 14)
Use the included “M3×25”Fixing screw for MDU. The terminal cover is removable, so use caution when handling it. (Figure 15)
Fixing screw for MDU
M3×25
(tightening torque: 0.6 to 0.8 N·m)
(Figure 15)
Caution Do not forcefully pull the connection cable. Doing so may result in a disconnection of the cable.
Click!
Insert
straight
MDU connector Connector Connection cable
MDU
connector

11
Install with an amount of space left equal to the measurement on the right or higher. (Figure 17)
(1) Insert the terminal block and
mounting bracket connected to
the MDU into the holes cut into the panel,
from the front of the panel. (Figure 18)
Panel
MDU Terminal
block
Mounting
bracket
(Figure 18) (Figure 19) View from bottom of MDU View from behind panel
MDU
connector
FG terminal
screw M4×6
(tightening torque:
1.4 to 1.8 N·m)
Nuts (M3)
(tightening torque: 0.6 to 0.8 N·m)
(Figure 20)
(2) Insert the MDU so that it is pushing against
the panel. (Figure 19)
Push it against the panel so that the two
mounting bracket holes enter into the screw
points, from the back of the panel.
(3) Insert the included nuts (M3) into the
screw points from the back of the panel,
and then tighten them into place. (Figure 20)
MDU panel cutting dimensions
Use a panel with a board thickness
from 1 mm to 3.2 mm.
1Precautions for mounting
2MDU panel mounting
Model
198
208
263
383
221
158
250 A
frame
800 A
frame
NF250-SEV
with MDU
NF800-SEW
with MDU
NF800-HEW
with MDU
NF250-HEV
with MDU
244
374
205
400 A
frame
NF400-SEW
with MDU
NF400-HEW
with MDU
A B
(No transmission, with pulse output)
72
86.5
R2
(Figure 16)
C
L
C
L
(Figure 17)
Caution
Screw point Screw point
MDU
3.3 MDU mounting (panel mounting)
3.3.1 No transmission, electric energy pulse output
Rear type and plug-in type are
shown. For rear type, leave some
space with the connection wiring,
insulation barrier, etc.
Caution When mounting the MDU to the panel, be careful not to damage the terminal block or cables.
A B
C
L
C
L

12
Caution
MDU connector
Connection cableConnector
●Fasten the connection cable with clamps to avoid
undue force.
(1)
(2) Insert until you hear it click into place.
Click!
(1) Connect the connector of the connection cable to the connector of
the MDU Breaker main unit's right side.
Securely insert the connection cable coming out from the MDU Breaker main unit into the MDU connector (until the lock clicks into place). (Figure 21)
<Connecting the connector> (Figure 21)
<Binding the cable>
[1] Insert the connector into the MDU connector
with the lock area of the connector to the top.
[2] Insert until you hear it
click into place.
FG terminal screw
3Connecting cable connection
MDU connector
Click!
Insert straight
MDU
connector Connector Connection cable
Binding band
attachment location Caution
Secure with the binding band in
such a way that direct force is not
applied to the MDU connector.
(No binding band is included.)
Caution Do not forcefully pull the connection cable. Doing so may result in a disconnection of the cable.

13
MDU connector
View from behind panel
(Figure 25)
Nuts (M3)
(tightening torque: 0.6 to 0.8 N·m)
FG terminal screw
Screw (M4×6)
Tightening torque
1.4 to 1.8 N·m
FG wire (green)
MDU
Terminal block
( )
( )
Screw (M3×12)
tightening torque
0.6 to 0.8 N·m
( )
Screw (M3×12)
tightening torque
0.6 to 0.8 N·m
fixing bracket
(Figure 24)
3.3.2 With CC-Link communication/MODBUS communication
Install with an amount of space left
equal to the measurement on the right
or higher. (Figure 23)
(1) Connect the terminal block to the fixing bracket. (Figure 24)
(Use the two included “M3×12”screws.)
MDU panel cutting dimensions
Use a panel with a board thickness
from 1 mm to 3.2 mm. (Figure 23)
1Precautions for mounting
3Mounting of terminal block to fixing bracket
2MDU panel mounting
(2) Insert the terminal block and fixing
bracket connected to the MDU into the
holes cut into the panel, from the front
of the panel.
(1) Screw the FG wire (green) pulled
from the MDU to the FG terminal
on the fixing bracket.
(Use the included “M4×6”screw.)
(2) Insert the MDU so that it is pushing against
the panel.
Push it against the panel so that the two
fixing bracket holes are inserted into
the screw points, from the back of the panel.
(Refer to 3.3.1 Figure 19 on page 11.)
(3) Insert the included nuts (M3) into the screw
points from the back of the panel, and then
tighten them into place. (Figure 25)
Model
218
228
282
402
221
158
250 A
frame
800 A
frame
NF250-SEV
with MDU
NF800-SEW
with MDU
NF800-HEW
with MDU
NF250-HEV
with MDU
263
393
205
400 A
frame
NF400-SEW
with MDU
NF400-HEW
with MDU
A B
(CC-Link/MODBUS)
Caution
Caution
(Figure 22)
72
86.5
R2
C
L
C
L
Rear type and plug-in type
are shown. For rere type,
leave some space with the
connection wiring, insulation
barrier, etc.
When mounting the MDU to the panel, be careful
not to damage the terminal block or cables.
A B
C
L
C
L

14
●After inserting the electric wire into the terminal, tighten it using the applicable tightening torque.
When tightening screws again, start slowly and do so in the vertical direction.
Applicable tightening torque : 0.5 to 0.6 N·m
Flathead screwdriver as a tool : Tip thickness of 0.6 mm, total width of 3.5 mm
[Recommended screwdriver: PHOENIX CONTACT screwdriver model SZS 0.6 ×3.5]
Electric wire covering stripped length : 7 mm
●Electric wire terminal treatment: For a solid wire, the electric wire can be connected with the
covering stripped.
For a twisted wire, strip the covering, twist the core, and then insert it into the junction area.
Make sure that the core filler does not short neighboring poles. Do not solder the core.
The following pin terminals (crimped terminals) are also available for purchase.
PHOENIX CONTACT
Electric wire cross-section area of 0.25 mm2 : AI 0.25-8 YE (product number 3200852)
Electric wire cross-section area of 0.5 mm2 : AI 0.5-8 WH (product number 3200014)
Electric wire cross-section area (for two wires) of 0.5 mm2× 2 : AI-TWIN 2 ×0.5-8 WH (serial number 320933)
The products listed above may not be compatible with some electric wires. For details, contact the pin terminal (crimped terminal) manufacturer directly.
However, if using a pin terminal (crimp terminal) with a metallic portion longer than 7 mm, cut the metallic portion to 7 mm as shown in the figure below.
Do not forcefully pull the connection
cable. Doing so may result in a
disconnection of the cable.
3.4 Wiring of MDU terminal block
3.4.1 External mounting type
3.4.2 Panel mounting type
●See below for compatible electric current sizes for the MDU terminal block.
One connected
Two connec te d
Solid wire
φ0.45 to φ1.2 mm
φ0.45 to φ0.8 mm(*)
0.14 to 1.5 mm2
0.14 to 0.75 mm2
Twisted wire
Pin terminal
Metallic portion
Cut here. 7 mm
L2L1
MDU
Insulated crimp
terminals
Caution
Caution
Securely insert the connection cable coming out from the MDU Breaker main unit into the MDU connector (until the lock clicks into place).
(3.3.1 Figure 21 on page 12.)
●Use a suitable size of electric wire for crimped terminal.
●Ground (class D) the earth terminal. Connect earth terminal to mounting plate with the cable FG (green) from MDU unit.
●Do not connect three or more electric wires to avoid heating or fire due to loose connection.
●Do not connect anything to unsused terminals. Erroneous connection will cause failure.
●Do not put too much tension on electric wire to avoid pulling terminal block out.
4Connecting cable connection
Caution
Caution
<Binding the cable>
Binding band
attachment
location
Secure with the binding band in
such a way that direct force is not
applied to the MDU connector.
(No binding band is included.)

15
[Wiring for products with electric energy pulse output]
Caution
[Wiring for products with CC-Link communication]
Caution
Danger
●The 114 and 113 pulse output terminals are included with MDUs with electric energy pulse output.
●The pulse output line forms a small-signal circuit. Install it at least 10 cm away from strong circuits. The wiring length is determined by various
conditions such as the anti-noise performance of the pulse receiver. However, the wiring should not exceed 100 m.
●If using A/C for the pulse output power supply, make sure that the pulse receiver does not erroneously operate due to leak current caused by
conduit capacitance.
●CC-Link communication terminals DA, DB, DG, and SLD are included with CC-Link communication MDUs.
Connect these to the CC-Link transmission line. Never connect non-transmission line terminals (such as the L1 and L2 control power supply
terminals).
The CC-Link transmission line forms a small-signal circuit. Connecting it improperly is extremely dangerous.
●The CC-Link transmission line forms a small-signal circuit. Install it at least 10 cm away from strong circuits.
However, install it at least 30 cm away if parallel for a long distance.
●If installing a MDU main unit with CC-Link communication, a hole cannot be made in the face board. Making a hole in the face board will leave
a gap in the CC-Link communication cable wiring.
[Wiring for products with MODBUS communication]
Caution
Danger
●MODBUS communication terminals FG, SLD, 485+, 485-, Ter are included with MODBUS communication MDUs.
Connect these to the MODBUS transmission line. Never connect non-transmission line terminals (such as the L1 and L2 control power supply
terminals).
The MODBUS transmission line forms a small-signal circuit. Connecting it improperly is extremely dangerous.
●The MODBUS transmission line forms a small-signal circuit. Install it at least 10 cm away from strong circuits.
However, install it at least 30 cm away if parallel for a long distance.
● If installing a MDU main unit with MODBUS communication, a hole cannot be made in the face board. Making a hole in the face board will leave
a gap in the MODBUS communication cable wiring.

16
4. MDU Features and Functions
4.1 Features of MDU
4.2 Functions of MDU
●The load current, line voltage, harmonic current (fundamental frequency; 3rd, 5th, 7th, 9th, 11th, 13th, 15th, 17th, and 19th order; and total),
electric power, reactive power, electric energy, reactive energy, power factor, and frequency flowing to MDU Breaker can be measured and displayed.
●When MDU Breaker is tripped, the fault cause and fault current are stored in non-volatile memory. This information can be used to identify
fault causes and recover.
●The maximum value of measurement items such as demand current and time electric energy is stored in non-volatile memory, along with when the
maximum value occurred. This information can be used to identify peak energy usage times.
●The LCD backlight color changes from white to red when an alarm (PAL, OVER) or fault occurs, allowing users to notice abnormalities even
from far away.
●Data such as measurement values, maximum values (and maximum value occurrence times), fault causes, fault current, and the alarm
status can be sent over a field network (CC-Link, MODBUS).
●Some models do not measure or display (transmit) some items. These items and functions will be skipped.
Caution
*1. Refer to “4.3 Measurement functions”for details of measurement functions.
*2. Either the latest fault cause or the latest fault current is shown. They are not displayed simultaneously.
*3. Electric energy pulse output, CC-Link communication, and MODBUS communication can not be installed at the same time.
*4. The CC-Link version is “CC-Link Ver. 1.10.”
*5. During MDU panel mounting, a CC-Link/MODBUS cable (part no. FANC-110SBH manufactured by Kuramo Electric Co., LTD.) is used from the
front surface of the MDU to the terminal block on the rear surface.
*6. When the MDU control power supply is turning on, a transitional inrush current will be generated. (Inrush current maximum value 2 A,
energization time 1 ms [240 VAC].)
*7. Refer to “6.1 Contact capacity and combinations for alarm contact output”in “MDU Breaker Instruction Manual for Main Unit”for alarm
contact output combinations.
Measurement
functions
(*1)
Load current I ○
Line voltage V ○
Harmonic current IH ○
Electric power P ○
Reactive power Q ○
Electric energy EP ○
Reactive energy EQ ○
Power factor PF ○
Frequency Hz ○
○
○
○
○
○
○
○
Fault cause,
Fault current
(*2)
Long time delay
Short time delay
Instantaneous
Line system
Output
specifications
(*3)
No transmission (standard product)
Electric energy pulse output (option)
CC-Link communication (option) (*4) (*5)
MODBUS communication (option) (*5)
MDU control power supply (permissible voltage
range 85% to 110%)
Alarm contact (MDU Breaker main unit option)
(Refer to “4.4 Monitoring functions”) (*7)
100 to 240 VAC/DC common 12 VA (*6)
PAL, TI
1φ2W, 3φ3W, 1φ3W (applied to three-pole products), 3φ4W (applied to four-pole products)

17
4.3 Measurement functions
4.3.1 Measurement function list
Measurement elements
Present value
Present demand value
All-phase demand maximum value
Maximum value between all wires
Maximum value occurrence time between all wires
All-phase demand maximum value occurrence time
Present value
Present value
Demand value
Demand value
Demand value
Integrated value
Latest one hour amount
One hour amount maximum value
Occurrence time of one hour amount maximum value
Integrated value
Latest one hour amount
One hour amount maximum value
Occurrence time of one hour amount maximum value
Fundamental frequency maximum value for all phase
Each-order maximum value for all phase
Occurrence time of each-order maximum value for all phase
All-phase each-order content ratio
All-phase total distortion ratio
Occurrence time of fundamental frequency maximum value for all phase
Present value
Maximum value occurrence time
Present value
Present value
Maximum value
Present value
Each-phase fundamental frequency
Each phase, each order (3rd, 5th, 7th,
9th, 11th, 13th, 15th, 17th, 19th order)
Total harmonic for each phase
Each-phase 0.0, 1.2 to 999.9, 1000 to 1600 A
00/01/01 00:00 to 99/12/31 23:59
Total harmonic (average value)
Maximum phase
Each-phase
Total harmonic for each phase
Total harmonic maximum value for all phase
Occurrence time of total harmony
maximum value for all phase
Maximum value occurrence time
Maximum value
Present value
Maximum value occurrence time
Maximum value
Maximum value
Present value
Total harmonic (average value)
Between each line
Communication
Display Display rauge*
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●●
–
–
–
–
–
–
–
–
The following table lists measurement elements and elements that can be communicated/displayed.
Measurement elements that can be communicated and displayed.
I
Load current
(±1.0%)
V
Line voltage
(±1.0%)
P
Electric power
(±1.5%)
Q
Reactive power
(±2.5%)
EP
Electric energy
(±2.0%)
EQ
Reactive energy
(±3.0%)
PF
Power factor
(±5.0%)
Hz
Frequency
(±2.5%)
IH
Harmonic current
(±2.5%)
Fault current (±15%)
* The minimum value and the maximum value of the display range differ depending on the rated current of the MDU breaker. For details,
refer to “4.3.2 Measurement rated values/measurement range and accuracy”.
0.0, 1.2 to 999.9, 1000 to 1600 A
00/01/01 00:00 to 99/12/31 23:59
0.0, 22.0 to 99.9, 100 to 759 V
00/01/01 00:00 to 99/12/31 23:59
-2103 to -1000, -999.9 to 999.9,
1000 to 2013 kW
00/01/01 00:00 to 99/12/31 23:59
-2103 to -1000, -999.9 to 999.9,
1000 to 2013 kver
00/01/01 00:00 to 99/12/31 23:59
0.0 to 99999.9 kWh（250 A frame）
0 to 999999 kWh（400/800 A frame）
00/01/01 00:00 to 99/12/31 23:00
0.0 to 99999.9 kverh（250 A frame）
0 to 999999 kverh（400/800 A frame）
00/01/01 00:00 to 99/12/31 23:00
LAG 50.0 to LAG 99.9, 100.0,
LEAD 99.9 to LEAD 50.0%
00/01/01 00:00 to 99/12/31 23:59
0.0, 45.0 to 65.0 Hz
0.0, 2.5 to 99.9, 100 to 800 A
00/01/01 00:00 to 99/12/31 23:59
0.0, 2.5 to 99.9, 100 to 800 A
00/01/01 00:00 to 99/12/31 23:59
0.0, 2.5 to 99.9, 100 to 800 A
0 to 12800 A
0.0 to 99.9, 100%

18
4.3.2 Measurement rated values/measurement range and accuracy
Electric current total present value
I3
(I1 + I3) / 2
(I1 + I2 + I3) / 3
Maximum phase applicable phase
I3
I1, I3
I1, I2, I3
I1, I2, I3, IN
Line system
Single-phase 2-wire
Single-phase 3-wire
Three-phase 3-wire
Three-phase 4-wire
250
125-250 adjustable
(in 12.5 A steps)
Rated current In (A)
Accuracy (±1.0% of In) (*)
Measurement lower limit current (1% of In)
Measurement upper limit current (In ×2)
400
±4.0 A
4.0 A
800 A
630
±6.3 A
6.3 A
1260 A
800
±8.0 A
8.0 A
1600 A
Setting value
0 to 15 min. (per 1 min.)
Item
Demand time limit
Display
Blinks at measurement upper limit current Fixed at measurement upper limit current
Communication
0 ALess than 1% of In
Measurement upper limit current exceeded
(1) Electric current
[1] The present value is the effective value during a single cycle.
[2] “Each-phase”means the 1-, 2-, 3-, and N-phase.
[3] Totals (average value) are calculated as follows when setting the phase and wire (factory setting is three-phase three-wire for three-pole
products, and three-phase four-wire for four-pole products).
The present value of the maximum phase electric current and present value of the maximum phase electric current demand indicate the maximum
value of the following phases via setting the phase and wire.
[4] The electric current demand time limit can be set as follows. The demand time limit is a bulk setting value that includes other measurement
elements. (Factory setting is two min.)
[5] The all-phase demand maximum value indicates the maximum value of the demand value for all phases, from when usage began (after
previous reset) to now.
[6] The electric current measurement rated value, measurement range, and measurement accuracy are shown below.
[7] Display/communication values will be as follows in the following conditions.
* The measurement accuracy is the ratio versus In, regardless of the rated voltage.
Current setting Ir (A) 200-400 adjustable 300-630 adjustable 400-800 adjustable
±2.5 A
2.5 A
500 A

19
Display
Blinks at 759 V Fixed at 759 V
Communication
0 VLess than 22 V
Measurement upper limit voltage
exceeded
[6] Display/communication values will be as follows in the following conditions.
440 V
80 V (displays up to 22 V, but anything less than 80 V is a reference value)
759 V
±4.4 V (±1.0% of measurement rated voltage)
Measurement lower limit voltage
Measurement upper limit voltage
Measurement rated voltage
Accuracy
(2) Voltage
[4] The maximum value between all wires indicates the maximum value of all line voltages, from when usage began (after previous reset) to now.
[5] The voltage measurement rated value, measurement range, and measurement accuracy are shown below.
[1] The present value is the effective value during a single cycle.
[2] “Between each line” means the between phases, such as between 1-phase and 2-phase, 2-phase and 3-phase, 3-phase and 1-phase,
1-phase and N-phase, 2-phase and N-phase, and 3-phase and N-phase.
[3] Totals (average value) are calculated as follows when setting the phase wire type. (Factory setting is three-phase three-wire for three-pole
products, and three-phase four-wire for four-pole products.)
The maximum value between all wires indicates the maximum value of the following interphases via setting the phase and wire.
Setting value
0 to 15 min. (per 1 min.)
Item
Demand time limit
400250 630 800
Rated current In (A)
Measurement upper limit electric power
Measurement lower limit electric power
Measurement upper limit reactive power
Measurement lower limit reactive power
1,052 kW
-1,052 kW
1,052 kvar
-1,052 kvar
1,656 kW
-1,656 kW
1,656 kvar
-1,656 kvar
2,103 kW
-2,103 kW
2,103 kvar
-2,103 kvar
657.3 kW
-657.3 kW
657.3 kvar
-657.3 kvar
(3) Electric power/Reactive power
[1] The present value is the effective value during a single cycle. (The electric power during reverse power flow is also measured.)
[2] The demand time limit is a bulk setting value that includes other measurement elements. (Factory setting is two min.)
[3] The measurement rated electric power/reactive power, measurement range, and measurement accuracy are shown below.
●If either the load current or line voltage exceeds the measurement upper limit, this will be the upper
limit (lower limit) even if at or below the electric power/reactive power listed above.
√3 ×In ×440 V
Measurement rated electric power ±1.5%
Measurement rated reactive power ±2.5%
Measurement rated electric power
Measurement rated reactive power
Electric power accuracy
Reactive power accuracy
Measurement upper limit
Measurement lower limit
Note: The display value will also blink if either the load current or line voltage reaches the measurement upper limit value.
[4] Display/communication values will be as follows in the following conditions.
Display
0 kW / 0 kvar
Blinks at measurement lower limit
electric power/reactive power
Communication
Fixed at Measurement lower limit
electric power/reactive power
All I are less than 0.4% of In
All V are 0 V (less than 22 V)
Less than measurement lower limit
electric power/reactive power
Blinks at measurement upper limit
electric power/reactive power
Fixed at measurement upper limit
electric power/reactive power
Measurement upper limit
electric power/reactive power exceeded
Voltage total present value
V23
(V12 + V23) / 2
(V12 + V23 + V31) / 3
Maximum phase applicable phase
V23
V12, V23
V12, V23, V31
Line system
Single-phase 2-wire
Single-phase 3-wire
Three-phase 3-wire
Three-phase 4-wire