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HITACHI DYNAMIC BRAKING UNIT (BRD SERIES)
NB4882CX
NOTE: BRD-EZ2-110K is replaced by BRD-EZ3-110K
200V Class (BRD-E2-30K/55K)
400V Class (BRD-EZ2-30K/55K/110K)
OPERATION MANUAL
CONTENTS
1. UNPACKING INSPECTION..................................................................... 1
2. IMPORTANT NOTICES........................................................................... 1
3. INSTALLATION....................................................................................... 2
4. WIRING AND FUNCTION SETTING...................................................... 3
4.1 Wiring Notices ......................................................................................................... 3
4.2 Functional Setting.................................................................................................... 5
4.3 Example of External Connection .............................................................................. 6
4.4 Example of External Connection
(Parallel Connection Operation)............................................................................... 7
5. TROUBLESHOOTING............................................................................. 9
5.1 Alarm contact is activated and the inverter stops ...................................................... 9
5.2 When the inverter trips the 0V during inverter deceleration ...................................... 10
6. PRE-START CHECKS.............................................................................. 11
7. SPECIFICATIONS.................................................................................... 12
7.1 Standard Specifications............................................................................................ 12
8. INTERNAL CIRCUITS............................................................................. 16
9. SELECTION OF DYNAMIC BRAKING UNITS AND
DISCHARGING RESISTORS................................................................... 20
9.1 Braking Energy without a Dynamic Braking Unit ..................................................... 21
9.2 Using the Dynamic Braking Unit.............................................................................. 21
9.3 General Formulas Use for Estimation....................................................................... 23
10.MAINTENANCE AND CHECKS............................................................. 24
10.1 Notices on Maintenance and Checks......................................................................... 24
10.2 Check Items ............................................................................................................. 24
11.PARTS ORDERING AND INQUIRY ....................................................... 26
APPENDIX .................................................................................................... 27
Read and Save this Instruction Manual.
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IMPORTANT NOTICES
Keep this manual handy for quick reference.
Read this manual carefully before installing, operating or maintaining the dynamic braking unit.
Familiarize yourself with the device specifications, safety precautions, and handling and operating
procedures and use this device correctly.
For maximum efficiency and safety, use this device at the specified operating rates for which it is
designed. Inspect and maintain this device at specified regular intervals to insure safe and
maximum performance and to prevent malfunction.
LIMITED WARRANTY
Your product is warranted against defective material or workmanship for a period of one year
from the date of installation. Hitachi will repair or replace this device free of charge if any
defective parts or workmanship covered within the limitations of this warranty are found.
The following are not covered by this warranty and will be charged accordingly:
(1) Abnormal handling or use of this device
(2) Failure caused by reasons unrelated to this device
(3) Improper servicing, alteration or modification by any unauthorized personnel
(4) Malfunction and failure caused by natural disasters such as fire and earthquakes
The obligation of the warrantor is solely to repair or replace the device. The warrantor is not
liable for any incidental or consequential damages caused by any defects of this device.
(This warranty is valid only in Japan.)
REPAIR COST
Repairs for normal wear, accidental damage or inspection of this device outside the warranty
period (one-year) will be at the owners' expense. Repairs not described in the above warranty are
possible. For more information on repair cost and inspections, call your local Hitachi distributor
or service center.
ORDERING REPLACEMENT PARTS AND INQUIRY
In the case of device failure, please report the following to your local Hitachi distributor or service
center:
(1) Model number
(2) Date of purchase
(3) Manufacturing number (MFG. No.)
(4) Details of the malfunction
It is recommended you install a back-up device so that your work is not disrupted.
MISCELLANEOUS
• This manual is subject to change without prior notice.
• This manual is included with the device. There is no other manual. Keep this manual handy.
• Reproduction or use of any portion of this manual, without express written permission from
Hitachi is prohibited.
• Every effort has been made to supply complete and accurate information. However, errors and
inaccurate information may exist. Please inform us of these errors. Your comments are always
welcome.
• Hitachi assumes no responsibility for any results caused by the use of this manual
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History revisions
No. Description Date of revision Manual No.
1 Two manuals have been combined and the contents reviewed. '98-4-25 NB4882C
Misspellings, missing characters, ambiguous descriptions, and similar errors are corrected without
notice.
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SAFETY PRECAUTIONS
Title: (Danger.eps)
Creator: Adobe Illustrator(TM) 7.0
:
Title: (Triangle.eps)
Creator: Adobe Illustrator(TM) 5.5
:
This safety reminder indicates potential danger to body and property.
Title: (Triangle.eps)
Creator: Adobe Illustrator(TM) 5.5
Carefully read this manual and other precautionary documents that came with the dynamic
braking unit before installing, operating or maintaining this unit. Familiarize yourself with the
device specifications, safety precautions, and handling and operating procedures and use this
device correctly.
This manual uses two symbols, the first informs of malfunctions and the second indicates danger
of personal injury or property damage.
This safety reminder indicates potentially life-threatening situations.
DANGER
If these instructions are not followed serious injury and in extreme
cases, death could occur.
CAUTION
If these instructions are not followed minor or serious injury and/or
property damage could occur.
Be sure to follow these instructions carefully when you see these symbols.
Also read and follow the instructions for all "Notes" and "Remarks."
1. Installation
CAUTION
l Mount the dynamic braking unit on a fireproof wall (e.g. metallic wall) or a fire may
occur.
(See page 2.)
l Keep the dynamic braking unit away from combustible or flammable materials or a fire
may occur.
(See page 2.)
l Never hold the dynamic braking unit by the front cover when carrying it. It could fall
and an injury could occur.
(See page 2.)
l Never allow any wires, dust, welding spatters, iron filings, or other materials to get into
the unit or a fire may occur.
(See page 2.)
l The dynamic braking unit is very heavy. Install the unit on a solid rigid wall strong
enough to support it. Otherwise, it could fall and an injury may occur.
(See page 2.)
l Do not use any inverter that is partially damaged or incomplete or an injury may occur.
(See page 2.)
l Avoid any dangerous environment
Do not place the dynamic braking unit in hot, damp, or wet locations. Don't use the
dynamic braking unit in the presence of dust, corrosive gases, explosive gases,
flammable gases, oil mist, or salt. Keep the dynamic braking unit out of direct
sunlight.
(See page 2.)
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2. Wiring
Title: (Danger.eps)
Creator: Adobe Illustrator(TM) 7.0
Title: (Triangle.eps)
Creator: Adobe Illustrator(TM) 5.5
DANGER
l Always connect the grounding wire to the dynamic braking unit to prevent electric
shock or fire.
(See page 3.)
l All wiring should be done by a qualified electrician or electric shock or fire may occur.
(See page 3.)
l Before wiring, make sure the supply power is off (or the P-N voltage is 45 V or less) to
prevent electric shock or fire.
(See page 3.)
l Always install the dynamic braking unit on the wall before wiring to prevent electric
shock and personal injury.
(See page 3.)
l Be sure to provide a thermal relay and a circuit, which shuts off primary power to the
inverter. This is to prevent burning-out the external resistor due to overheating if the
dynamic braking unit malfunctions.
(See page 3.)
For actual connections, see 4.3 and 4.4.
(See page 3.)
CAUTION
l Make sure the voltage rating of the dynamic braking unit is equal to that of the inverter
to prevent fire and personal injury.
(See page 3.)
l Do not connect resistors directly to the D.C. terminals (P and N) or fire may occur.
(See page 3.)
l Tighten screws at their correct specified torque (see table on right). Make sure every
screw is firmly tightened or fire may occur.
(See page 3.)
l The power cables should be MLFC flame-retardant poly-flex wire, allowing a voltage
of 600 V and capable of the specified amperage or fire may occur.
(See page 3.)
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3. Control and operation
Title: (Danger.eps)
Creator: Adobe Illustrator(TM) 7.0
Title: (Triangle.eps)
Creator: Adobe Illustrator(TM) 5.5
Title: (Danger.eps)
Creator: Adobe Illustrator(TM) 7.0
DANGER
l Be sure the front cover on the dynamic braking unit is attached before turning on the
power. Never remove the cover of the dynamic braking unit or you may receive an
electric shock
(See page 11.)
l Do not operate with wet hands or you may receive an electric shock.
(See page 3.)
l Never touch any terminal of the dynamic braking unit while the unit power is on (even
when the unit has stopped) or you may receive an electric shock.
(See page 3.)
l Never touch any part or put anything in the dynamic braking unit while the unit's power
is on or you may receive an electric shock or cause a fire.
(See page 3.)
CAUTION
l The heat radiating fins and the discharging resistors during use are hot and can cause
burns. Do not touch.
4. Maintenance, inspection and part replacement
DANGER
l Be sure to turn off the supply power. (Make sure that the DC voltage between
terminals P and N is 45 volts or less.) Otherwise, you may receive a serious electric
shock.
(See page 24.)
l Only an authorized electrician is allowed to check, maintain, and replace parts of the
dynamic braking unit.
(Take off all metallic accessories such as watches and jewelry before operating.)
(Use the insulated tools.)
Otherwise, you may receive a serious electric shock or personal injury.
(See page 24.)
(See page 3.)
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5. Appendix
Title: (Danger.eps)
Creator: Adobe Illustrator(TM) 7.0
DANGER
l Never alter or modify the dynamic braking unit.
Improper servicing may cause serious electric shock and/or personal injury.
(See page 1.)
GENERAL NOTICES
For simplicity, some figures and illustrations in this manual are shown without the cover
or peripheral parts of the device. Be sure to remount the cover and other safety features
before running the dynamic braking unit.
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1. UNPACKING INSPECTION
Handle the product with care when unpacking. Do not use any excessive force (impacts,
vibration, etc.) on the package. Check the following:
(1) Package damage occurring during delivery
(2) Model name, voltage, etc. (order confirmation)
(3) List of accessories (including operation manual)
2. IMPORTANT NOTICES
Note the following to improve and perform safe operation of the dynamic braking unit:
DANGER
l Never alter or modify the dynamic braking unit.
Improper servicing may cause serious electric shock and/or personal injury.
Note: Do not use the BRD-E2/E2Z braking unit in combination with earlier versions, (e.g.
BRD-VZ or BRD-C1). The operating voltages and terminal configurations are
different and may cause the dynamic braking units to malfunction.
Note: Set the DIP switches and connect the wires correctly when setting or changing the
operating voltage or when running devices in a parallel connection. Be sure to turn
off power to the dynamic braking unit before setting the DIP switches and the
connecting wires. (For more information, see "4. Wiring and Function Setting.")
Note: Check wirings and connections carefully. If they are correct you can turn on the
power to the inverter.
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3. INSTALLATION
Title: (Triangle.eps)
Creator: Adobe Illustrator(TM) 5.5
5 cm or more
5 cm or more
5 cm or more
5 cm or more
CAUTION
l Mount the dynamic braking unit on a fireproof wall (e.g. metallic wall) or a fire may
occur.
l Keep the dynamic braking unit away from combustible or flammable materials or a fire
may occur.
l Never hold the dynamic braking unit by the front cover when carrying it. It could fall
and an injury could occur.
l Never allow any wires, dust, welding spatters, iron filings, or other materials to get into
the unit or a fire may occur.
l The dynamic braking unit is very heavy. Install the unit on a solid rigid wall strong
enough to support it. Otherwise, it could fall and an injury may occur.
l Do not use any inverter that is partially damaged or incomplete or an injury may occur.
l Avoid any dangerous environment
Do not place the dynamic braking unit in hot, damp, or wet locations. Don't use the
braking unit in the presence of dust, corrosive gases, explosive gases, flammable gases,
oil mist, or salt. Keep the braking unit out of direct sunlight.
To insure ventilation, mount the dynamic braking unit on the wall with at least 10 cm clearance
above and below the unit and at least 5 cm clearance on the left and right sides of the unit as
shown in Figure 3.1, Figure 3.2 (a), and Figure 3.2 (b).
Do not place the dynamic braking unit with its ventilation openings facing left and right
(horizontally).
Required clearance surrounding the dynamic braking unit
10 cm or more
10 cm or more
10 cm or more
10 cm or more
(a) Horizontal installation (b) Vertical installation(Never place the dynamic braking
unit with its ventilation openings
facing left and right.)
10 cm or more
10 cm or more
Figure 3.1 Clearance around
dynamic braking units
E2-30K/55K and
EZ2-55K/110K
Figure 3.2 Clearance around dynamic braking units EZ2-30K
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4. WIRING AND FUNCTION SETTING
Title: (Danger.eps)
Creator: Adobe Illustrator(TM) 7.0
Title: (Triangle.eps)
Creator: Adobe Illustrator(TM) 5.5
4.1 Wiring Notices
DANGER
l Always connect the grounding wire to the dynamic braking unit to prevent electric
shock or fire.
l All wiring should be done by a qualified electrician or electric shock or fire may occur.
l Before wiring, make sure the supply power is off (or the P-N voltage is 45 V or less) to
prevent electric shock or fire.
l Always install the dynamic braking unit on the wall before wiring to prevent electric
shock and personal injury.
l Be sure to provide a thermal relay and a circuit, which shuts off primary power to the
inverter. This is to prevent burning-out the external single resistor due to overheating
if the dynamic braking unit malfunctions.
For actual connections, see 4.3 and 4.4.
CAUTION
l Make sure the voltage rating of the dynamic braking unit is equal to that of the inverter
to prevent fire and personal injury.
l Do not connect resistors directly to the D.C. terminals
(P and N) or fire may occur.
l Tighten screws at their correct specified torque (see
table on right). Make sure every screw is firmly
tightened or fire may occur.
l The power cables should be MLFC flame-retardant
poly-flex wire, allowing a voltage of 600 V and capable
of the specified amperage or fire may occur.
Notes:
1. Be sure to provide alarm contacts (AL1 and AL2) and a circuit, which shuts off
primary power to the inverter to prevent overheating and burning if the dynamic
braking unit malfunctions.
Screw size
M3 0.6 to 0.9
M5 2.8 to 3.9
M8 10 to 13.5
M10 21 to 28
Tightening
torque (N.m)
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2. Use cables at their specified ratings as short as possible: up to 5 meters between the
Inverter
dynamic braking unit and the inverter (P, N) and up to 50 meters between the dynamic
braking unit and the discharging resistor (P, RB) (or up to 5 meters for the EZ2-30K).
Also make the wire connections as short as possible. Do not loop extra cable.
Up to
50 meters
(up to 5
meters)*
Discharging
resistor
Example of correct wiring
Up to
5 meters
Dynamic
braking unit
* In the EZ2-30K system, the cable between the dynamic braking unit and the
discharging resistor must be 5 meters or shorter.
Example of incorrect wiring
Inverter
Dynamic
braking unit
Discharging
resistor
The cables must be tied together and supported firmly so there is no excessive load on
the dynamic braking unit.
3. When the parallel connection interlocking function is used, signal cables (MA1, MA2,
SL1, and SL2) between the dynamic braking units must be no more than five meters in
length and no more than 0.75 mm2 in width in its section area. The signal cable must
be fully separated from the main circuit cable.
Signal cableMain circuit cable
10 cm or more
4. When a combination of various resistors are used, the inductance in the resistors may
raise the surge voltage during the switching operation. To prevent this, use larger
cables or twist them.
Always use up to six non-induction resistors as external resistors.
5. Use insulated crimping terminals to connect the cables to the terminal board TM1 (or
TM2 of the EZ2).
6. Use closed-loop terminals with insulated caps to connect cables to the terminal board
TM2 (or TM3 of the EZ2).
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4.2 Functional Setting
2
You can select "Main unit," "Sub-unit," and an operating voltage level with the DIP switch.
Note: Be sure to turn off the dynamic braking unit when setting the DIP switch.
(1) Operating Voltage Set/Change function
The dynamic braking unit supports three operating voltage levels: Standard (factory-set), 5%, and -10%. You can select an operating voltage level by setting the DIP switch.
When an overvoltage trip occurs at a certain voltage or deceleration time, this function
reduces the operating voltage of the dynamic braking unit to prevent an overvoltage trip.
However, at a high input voltage, only the power will be turned on braking unit.
Determine the operating voltage level according to the receiving voltage.
Receiving voltage ×
(2) Parallel connection-interlocking function
You can run two parallel-connected dynamic braking units interlocked by connection of
their signal wires (MA1, MA2, SL1,and SL2) and setting of the DIP switches.
You can use one of the dynamic braking units as a sub-unit and allow it to work at the
operating voltage level of the main unit by setting the dynamic braking unit as a sub-unit by
the DIP switch.
Table 4.1 shows settings of the DIP switch.
Table 4.1 DIP switch setting
Function and operating voltage
Main unit
1
Operating voltage: Standard
363V (725V)
Main unit
2
Operating voltage: -5%
345V (689V)
Main unit
3
Operating voltage: -10%
326V (653V)
OFF, OFF, ON, X Factory-set
ON, OFF, ON,X
ON, ON, ON, X
+ 20 V < Operating voltage
•ã
DIP switch setting
(X: Any position)
Remarks
4 Sub-unit X, X, OFF, X
The value in parentheses indicates the operating voltage of the 400V-class dynamic braking unit.
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The operating voltage
correspond to a main unit.
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4.3 Example of External Connection
3-phase power supply
3-phase power supply
Figure 4.1 shows an example of a connection of a motor control system containing only one
dynamic braking unit.
Always use discharging resistors equal to or more than the resistance specified. If the
resistance is insufficient, the dynamic braking unit may be damaged.
To prevent overheating and burning during any malfunction of the dynamic braking unit, devise
a circuit to shut off the primary power of the inverter by connecting this circuit to the alarm
contact terminals (AL1 and AL2).
Figure 4.2 shows the connection of a thermal relay and Table 4.2 shows a list of applicable
wires.
400V class
Power supply
200V class
Inverter
Connection to the alarm terminal section
Thermal relay
(Usually closed (b contact) and
opens when it is working)
External
resistor
Thermal relay
(Note 2)
(Note 1)
Motor
Dynamic braking unit
(Main unit)
Note 1: Select relay RY according to the coil (Mg)
and contact (RY) specifications.
Note 2: R0, T0 terminals depend on inverter model.
Figure 4.1 External connection example
To the dynamic braking unit To the dynamic braking unit
To terminals of the external
resistor (when a 3-element
thermal relay is used)
To terminals of the external
resistor (when a 2-element 3terminal thermal relay is used)
Figure 4.2 Connection of a Thermal Relay
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4.4 Example of External Connection (Parallel Connection Operation)
3-phase power supply
Figure 4.3 shows a connection example of a motor control system, which uses the parallel
connection interlocking function.
In this case, both the main unit and the sub-unit must use external resistors of the same
resistance.
To prevent overheating and burning if the dynamic braking unit malfunctions, provide a thermal
relay to shut off the primary power of the inverter when the thermal relay is operating.
Figure 4.3 shows the connection of a thermal relay and Table 4.3 shows a list of applicable
wires.
400V class
Operating
power supply
200V class
Inverter
(Note 2)
Motor
Dynamic braking unit
Main unit
Dynamic braking unit
Sub-unit
(Note 1)
External
resistor
Thermal relay
External
resistor
Thermal relay
Note 1: Select relay RY according to the coil (Mg)
specifications and the contact (RY) specifications.
Note 2: R0, T0 terminals depend on inverter model.
Figure 4.3 External connection example for the parallel connection operation
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Table 4.2 Applicable wires
200V class
400V class
Note 1:
Model
E2-30K 8Ω or more 5.5mm2 or more 0.75mm2 or more 5.5mm2 or more
E2-55K 4Ω or more 14mm2 or more
EZ2-30K 17Ω or more 3.5mm2 or more
EZ2-55K 10Ω or more 8mm2 or more
EZ2-110K 6Ω or more 22mm2 or more
The wire for P, RB, and N connections should be MLFC wire (flame-retardant poly-flex wire, able to withstand
voltage of 600 V).
If the distance between the dynamic braking unit and a discharging resistor is 10 meters or more, use a cable
thicker than the specified wire size. Table 4.2 shows sizes of MLFC wire.
-1) If the distance is between 10 m (not including 10 m) and 25 m, use a wire size one rank larger.
-2) If the distance is between 25 m (not including 25 m) and 50 m, use a wire size two ranks larger.
However, the cable should be up to 5 m between the braking unit and the discharging resistor.
Connection
resistance
5Ω to 7.9Ω 8mm2 or more
4Ω to 4.9Ω 14mm2 or more
3Ω to 3.9Ω 22mm2 or more
2Ω to 2.9Ω 38mm2 or more
13Ω to 16.9Ω 5.5mm2 or more
10Ω to 12.9Ω 8mm2 or more
7.5Ω to 9.9Ω 14mm2 or more
6Ω to 7.4Ω 22mm2 or more
4Ω to 5.9Ω 38mm2 or more
3Ω to 3.9Ω 60mm2 or more
Wire for P, RB, and
N connections (Note1)
SL1, SL2,
MA1, MA2
Grounding wire
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5. TROUBLESHOOTING
5.1 Alarm contact is activated and the inverter stops
This event may be caused by a large amount of regeneration energy or a frequently
breaking that result in the overheating of the discharging resistor. To prevent this
event, check and correct resistances of the discharging resistors, the number of
dynamic braking units in use, and the deceleration time. This event also occurs
when incorrect connections are made or when the voltage is inappropriate. Follow
the instructions below to check and repair.
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5.2 When the inverter is tripped by overvoltage during inverter deceleration
This event may be caused by too much regeneration energy, which is unable to
handle the increase in voltage.
To prevent this problem, check and correct the resistances of the discharging
resistors, the number of dynamic braking units in use, and the deceleration time.
This problem occurs also when the discharging resistor is disconnected, when
wrong connections are made or when the DIP switch setting is improper. Follow
the instructions below to inspect and repair.
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6. PRE-START CHECKS
Title: (Danger.eps)
Creator: Adobe Illustrator(TM) 7.0
Title: (Triangle.eps)
Creator: Adobe Illustrator(TM) 5.5
Follow the safety instructions below before operating this device.
DANGER
l Be sure the front cover on the dynamic braking unit is attached before turning on the
power. Never remove the cover of the braking unit or you may receive an electric
shock.
l Do not operate with wet hands or you may receive an electric shock.
l Never touch any terminal of the dynamic braking unit while the braking unit power is
on (even when the braking unit has stopped) or you may receive an electric shock.
l Never touch any part or put anything in the dynamic braking unit while the braking
unit's power is on or you may receive an electric shock or cause a fire.
CAUTION
l The heat radiating fins and the discharging resistors during use are hot and can cause
burns. Do not touch.
Notes:
(1) Check the wiring and connections.
Wrong wiring or incorrect connection may cause the dynamic braking unit to
malfunction or cause damage.
(2) Check whether a non-grounding terminal has been used.
Grounding of a non-grounding terminal may cause the dynamic braking unit to
malfunction.
(3) Check whether there is any foreign material (wire, dust, crimping terminal, tool etc.) in
the dynamic braking unit.
Foreign materials in the dynamic braking unit may short-circuit the unit causing a
malfunction or damage.
(4) Check for short-circuiting and inspect the ground fault or the dynamic braking unit
may malfunction or cause damage.
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7. SPECIFICATIONS
7.1 Standard Specifications
Table 7.1 shows the standard specifications of the dynamic braking unit. However, user's
specifications (if any) should be used preferentially.
Table 7.1 Standard Specifications
Model E2-30K E2-55K EZ2-30K EZ2-55K EZ2-110K
Enclosure Open type
Voltage class applicable 200V-class 400V-class
Operating voltage (ON/OFF) 362.5±5V/355±5V
Service status indication LED ON
Discharging resistance I 4 ohms or more 2 ohms or more 10 ohms or
*1
725±5V/710±5V
more
Allowable operation cycle 1/5
Continuous ON time 2 minutes maximum 10 seconds
*2
1/10
*3
maximum
Discharging resistance II 6 ohms or more 4 ohms or more 24 ohms or more 12 ohms or
Allowable operation cycle Continuous
Protective function Protection of power modules against overheating
Thermal relay for protection
Operates at a cooling fin temperature of 100 °C.
Usually closed (b contact)
Contact rating: 240 VAC, 3A (R load), 0.2A (L load)
36 VDC, 2A (R load)
Minimum load: 15 VDC, 50 mA (R load)
Ambient temperature −10 to 50°C
Storage temperature −10 to 60°C
Relative humidity 20 to 90% (Non-condensing)
Vibration
*5
4.9m/s2 (0.5G) 10 to 55Hz 2.0m/s
2
(0.2G) 10 to 55Hz 4.9m/s
Installation site Up to 1000 meters above sea level, indoor (free from corrosive gases and dust)
General specifications
Coating color Munsell color system 5Y7/1 (The aluminum-cooling fin is not coated.)
Others Equipped with a parallel connection interlocking function (for main or subsidiary
unit)
*4
*1
6 ohms or more 3 ohms or more
*2
1/5
2 minutes maximum
6 ohms or more
more
2
(0.5G) 10 to 55Hz
*1 Operating voltage set/change: -5% and -10% (set by the DIP switch)
*2 Allowable operation cycle: 2 minutes ON and 8 minutes OFF
*3 Allowable operation cycle: 10 seconds ON and 90 seconds OFF
*4 Parallel connection operation: set by the DIP switch
*5 Conforms to the JIS C0911 (1984) test methods
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Page 20
Model
BRD-EZ2-30K HP DM
Type
TYPE FORM
Operating voltage Weight (kg)
725±5
2
Grounding terminal
(M5 screw)
TM2, terminal width 6, M3 screw
SL1 SL2 MA1 MA2 AL1 AL2
TM3, terminal width 13, M5 screw
N RB P P
Figure 7.1 Dimensions
DIMENSION in mm
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Page 21
Model
BRD-E2-30K HP DM
BRD-EZ2-55K HP DM
Type
TYPE FORM
Operating voltage Weight (kg)
362.5±5
725±5
Mounting hole
6
6
Grounding terminal
M5 screw
TM1, terminal width 6.4, M3 screw
SL1 SL2 MA1 MA2 2 1
Note: Leave terminals 1 and 2 disconnected.
TM2, terminal width 23, M8 screw
N RB P P
TM3, terminal width 5.9, M3 screw
AL2 AL1
Figure 7.2 Dimensions
DIMENSION in mm
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Page 22
Model
BRD-E2-55K HP DM
BRD-EZ2-110K HP DM
Type
TYPE FORM
Operating voltage (V) Weight (kg)
362.5±5
725±5
Mounting hole
8
10
Grounding terminal
M5 screw
TM1, terminal width 6.4, M3 screw
SL1 SL2 MA1 MA2 2 1
Note: Leave terminals 1 and 2 disconnected.
TM2, terminal width 33, M10 screw
N RB P P
TM3, terminal width 7.5, M3 screw
AL2 AL1
Figure 7.3 Dimensions
- 15 -
The value in parentheses is for EZ2-110K.
DIMENSION in mm
Page 23
8. INTERNAL CIRCUITS
Internal circuits of the dynamic braking units E2-30K/55K, EZ2-30K, and EZ2-55K/110K are
shown respectively in Figures 8.1 to 8.3. See 4.3 and 4.4 on how to connect the terminals.
1. Terminals of the E2-30K/55K and EZ2-55K/110K
(1) TM1
MA1, MA2, SL1, and SL2: Control signals for parallel interlocking connection
(2) TM2
P: DC voltage (+)
P, RB: Resistance
N: DC voltage (-)
(3) TM3
AL1, AL2: Alarm contacts
2. Terminals of the EZ2-30K
(1) TM2
MA1, MA2, SL1, and SL2: Control signals for parallel interlocking connection
AL1, AL2: Alarm contacts
(2) TM3
P: DC voltage (+)
P, RB: Resistance
N: DC voltage (-)
For actual terminal layouts and screw sizes, see Figures 7.1 to 7.3.
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200V-
class
inverter
Figure 8.1 Internal circuit
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Page 25
400V-
class
inverter
Figure 8.2 Internal circuit
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Page 26
400V-
class
inverter
Figure 8.3 Internal circuit
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9. SELECTION OF DYNAMIC BRAKING UNITS AND DISCHARGING
Output voltage (V)
DC smoothing
Converter
Inverter
RESISTORS
The synchronous speed of the motor decreases relative to a decrease in set frequency.
When this happens, the synchronous speed of the motor is less than the rotational speed of the
rotor and the slip becomes negative. Consequently, the torque generated by the motor operates
as a braking touque. See Figure 9.1.
This braking torque is a function of voltage verses frequency. For example, the difference
between the torque at frequency f1 and the torque at frequency f3 in Figure 9.2 is caused by the
difference between their voltage-vs-frequency ratios.
Torque-vs-speed curve at frequency f2
Torque-vs-speed curve at frequency f1
Torque-vs-speed curve
at frequency f3
Speed
Frequency
Figure 9.1 Frequency change and motor torque Figure 9.2 Voltage-vs-frequency
characteristics
(f)
In this status, the motor operates as a generator. The rotational energy of the motor is
converted into electrical energy and feed back into the inverter circuit. See Figure 9.3.
section
Power supply
circuit
circuit
Regeneration energy
Motor
Discharging resistor
Dynamic braking unit
Figure 9.3 Dynamic braking by the inverter
The regenerated energy is stored in the DC bus circuit of the inverter.
(Capacitor feedback type)
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Page 28
9.1 Braking Energy without a Dynamic Braking Unit
Rotational speed
Usually, the braking energy of a motor is the sum of the motor loss (including mechanical loss)
and inverter loss.
The overall efficiency of an inverter-controlled motor is 65% to 90% depending upon the motor
capacity and power loss, and the braking energy which fluctuates around 10% to 35% when at
frequency of 50 Hz to 60 Hz).
Generally, the braking torque of up to about 11 KW is about 20% of the rated torque of the
motor.
If regeneration energy is greater than the braking energy, the capacitor in the DC bus circuit will
be charged, thus increasing the DC voltage. This may cause the over-voltage protecting
circuit to shut off the output of the inverter. (The motor runs freely.)
9.2 Using the Dynamic Braking Unit
For a load with high inertia, the motor must be decelerated immediately, and the dynamic
braking unit (BRD) will need to absorb the resulting regeneration energy.
In Figure 9.3, when the voltage of the D.C. circuit reaches a preset value, the transistor Tr
switches on and the resistor RB consumes the regeneration energy as heat. In this status, the
V/F characteristics of the inverter, the permissive current (determined by the resistance of RB),
and the capacitance of RB in the dynamic braking unit will determine the braking torque.
This is because the torque generated by the motor is dependent upon the current passing
through Tr (and RB).
Do not combine any items which are blank in Table 9.1 to Table 9.3.
(1) For use in one dynamic braking unit
Table 9.1 For use in a single dynamic braking unit
(Common conditions)
totally-enclosed fan-cooled motor
• BRD operation frequency
• BRD continuous operation time tB •… 2 minutes
Time
• TB A : Mean braking torque at 3 Hz to 60 (or 50) Hz
(For meanings of A , see Figure 9.2.)
Motor
(kW)
110.0 110.0 1.83 ( 7.32) 719 ( 73.3) 595 ( 60.7) 80 150
Inverter
(kW)
18.5 22.0 0.16 ( 0.64) 122 ( 12.4) 101 ( 10.3) 170
22.0 22.0 0.19 ( 0.76) 144 ( 14.7) 120 ( 12.2) 150
30.0 30.0 0.30 ( 1.20) 197 ( 20.0) 164 ( 16.7) 110 175
37.0 37.0 0.35 ( 1.40) 243 ( 24.7) 202 ( 20.6) 85 170 142
45.0 45.0 0.40 ( 1.60) 295 ( 30.1) 245 ( 25.0) 75 140 116 195
55.0 55.0 0.55 ( 2.20) 361 ( 36.8) 300 ( 30.6) 60 120 95 160
75.0 75.0 1.03 ( 4.12) 492 ( 50.2) 407 ( 41.5) 70 115
90.0 90.0 1.23 ( 4.92) 588 ( 60.0) 487 ( 49.6) 58 95 190
Moment of inertia J
for one motor (GD2)
kg.m2 (kgf.m2)
Rated torque of the motor
To: N.m (kgf.m)
50Hz 60Hz
T
(4 poles)Motor: Hitachi standard 3-phase squirrel-cage
t
B
•… 0.2
t
C
(or •… 0.1 for the EZ2-30K)
(or •… 10 seconds for the EZ2-30K)
Motor torque ratio %
E2 EZ2
30K 55K 30K 55K 110K
4 Ω 2 Ω 10 Ω 6 Ω 3 Ω
B
A
T
B
A T
A
B
T
B
A
A
T
B
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Page 29
(2) For use in two dynamic braking units
Table 9.2 For use in two dynamic braking units
Motor torque ratio %
Motor
(kW)
Inverter
(kW)
Moment of inertia J
for one motor (GD2)
kg.m2 (kgf.m2)
Rated torque of the motor
To: N.m (kgf.m)
50Hz 60Hz
E2 EZ2
30K 55K 30K 55K 110K
4 Ω 2 Ω 10 Ω 6 Ω 3 Ω
T
B
A
T
B
A T
B
A
T
B
18.5 22.0 0.16 ( 0.64) 122 ( 12.4) 101 ( 10.3)
22.0 22.0 0.19 ( 0.76) 144 ( 14.7) 120 ( 12.2)
30.0 30.0 0.30 ( 1.20) 197 ( 20.0) 164 ( 16.7)
37.0 37.0 0.35 ( 1.40) 243 ( 24.7) 202 ( 20.6) 170
45.0 45.0 0.40 ( 1.60) 295 ( 30.1) 245 ( 25.0) 140 230
55.0 55.0 0.55 ( 2.20) 361 ( 36.8) 300 ( 30.6) 120 190
75.0 75.0 1.03 ( 4.12) 492 ( 50.2) 407 ( 41.5) 140 230
90.0 90.0 1.23 ( 4.92) 588 ( 60.0) 487 ( 49.6) 110 195
110.0 110.0 1.83 ( 7.32) 719 ( 73.3) 595 ( 60.7) 95 159
(3) Mean braking torque with one size bigger capacity
In a standard combination of a motor and an inverter, the braking torque is limited by the
overcurrent strength of the inverter. However, by increasing the rank of the inverter, you
can use the maximum torque of the motor.
Table 9.3 shows the braking torques of the inverters whose capacity is increased by one.
The motor capacity must be raised when 135% or more braking is required.
A
A
T
B
Table 9.3 Requirements for maximizing the braking torque of motor
(when the inverter capacity is increased by one)
Requirement:
‡@Mean braking torque 135% (To × 1.35) ‡A Increasing the inverter capacity by one
B
Inverter
(kW)
B
= 0.5 × T
Moment of inertia J
for one motor (GD2)
kg.m2 (kgf.m2)
‡B T
Motor
(kW)
18.5 22.0 0.16 ( 0.64) 122 ( 12.4) 101 ( 10.3) 1
22.0 22.0 0.19 ( 0.76) 144 ( 14.7) 120 ( 12.2) 1
30.0 30.0 0.30 ( 1.20) 197 ( 20.0) 164 ( 16.7) 2 1 1
37.0 37.0 0.35 ( 1.40) 243 ( 24.7) 202 ( 20.6) 2 1 1
45.0 45.0 0.40 ( 1.60) 295 ( 30.1) 245 ( 25.0) 2 1 2 1
55.0 55.0 0.55 ( 2.20) 361 ( 36.8) 300 ( 30.6) 2 2 1
75.0 75.0 1.03 ( 4.12) 492 ( 50.2) 407 ( 41.5) 2 2 1
90.0 90.0 1.23 ( 4.92) 588 ( 60.0) 487 ( 49.6) 2 1
110.0 110.0 1.83 ( 7.32) 719 ( 73.3) 595 ( 60.7) 2 1
B
A
‡C The operation frequency and other conditions are
the same as those in Table 9.1 and Table 9.2.
Number of sets of dynamic braking units
Rated torque of the motor
To: N.m (kgf.m)
50Hz 60Hz
30K 55K 30K 55K 110K
4 Ω 2 Ω 10 Ω 6 Ω 3 Ω
T
B
and resistors required
E2 EZ2
A
T
B
A T
A
B
A
T
T
B
A
B
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Page 30
9.3 General Formulas Use for Estimation
B
2
The example below calculates the braking torque and the discharging resistance of a motor for
traveling machine.
(1) Rated motor torque TM (N.m)
M
P
TM = 9550
×
M
N
where
PM: Rated capacity of the motor (kW)
NM: Rated revolutions per minutes of the motor (r.p.m.)
(2) Braking torque (required to decelerate) TB (N.m)
* While this value is negative, only the inverter can brake the motor. (The BRD is not
required.)
J× (N1 −N2)
TB =
9.55×t
L
−
T
where
J: Moment of inertia of the motor and the load (converted to motor shaft) (kg
N1, N2: Rotational speed (r.p.m.) before deceleration and rotational speed (r.p.m.) after
deceleration
TL: Load torque (converted to motor shaft) (N
t
: Deceleration time (seconds)
B
.
m)
.
m2)
(3) Discharging resistance R (ohms): Resistance relative to the inverter
* If this value is under the minimum value of a BRD, two or more BRDs are required.
R =
0.105 × TB × N1
on
1V
×
1.2
where
Von: BRD operating voltage (362.5 V for the 200V class or 725V for the 400V class)
(4) Mean discharging capacity PL (W)
* The capacity of the discharging resistor should be 2.5 to 3 times the result of the formula
below.
0.105 × (TB − 0.2×TM) × (N1 + N2)
PL =
2
t
B
×
t
C
where
t
: Operation cycle(s)
C
(5) Duty cycle tB/t
C
‡@The duty cycle (tB/tC) for the discharging resistor I is as follow:
t
B
t
C
•…
1
5
EZ2-30K:
t
B
t
C
•…
1
10
‡AThe dynamic braking unit can be used continuously for the use of the discharging
resistor II.
* See 9.3 (4) for capacities of the discharging resistors.
* See Table 7.1 for details of the discharging resistors I and II.
(6) Thermal set value
Thermal set value (A) ‡•
Rated capacity of the discharging resistor (W)
2
Resistance of the discharging resistor (Ω) ÷ 1.2
÷
* This is a reference value for enameled and ribbon resistors.
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10. MAINTENANCE AND CHECKS
Title: (Danger.eps)
Creator: Adobe Illustrator(TM) 7.0
When required, apply a voltage of 2000 VAC between the ground and the interconnected
10.1 Notices on Maintenance and Checks
DANGER
l Be sure to turn off the supply power. (Make sure that the DC voltage between
terminals P and N is 45 volts or less.) Otherwise, you may receive a serious electric
shock.
l Only an authorized electrician is allowed to check, maintain, and replace parts of the
dynamic braking unit.
(Take off all metallic accessories such as watches and jewelry before operating.)
(Use the insulated tools.)
Otherwise, you may receive a serious electric shock or personal injury.
Notes:
(1) Always keep the inside and outside of the dynamic braking unit clean. Always
connect cables correctly. Missing and wrong connections are prohibited. Tighten
the terminals and connectors firmly.
(2) Keep this device away from wet, oily, or dusty locations. Metallic filings in the
product can easily cause short-circuits, damage the unit or start a fire.
10.2 Check Items
(1) Daily checks
(2) Periodic checks (every one year) See Page 25.
(3) Insulation resistance test and dielectric strength test
Connect the terminals as shown below and test under the following conditions:
• Insulation resistance test
Measure the resistance between the ground and the interconnected terminals with a
meggar and make sure it is 5 megohms or more.
• Do not perform the dielectric strength test.
terminals for one minute and check for problems.
• Do not use any other terminals for the dielectric strength test.
• Be sure to increase and decrease the test voltage slowly.
Voltage applied
Meggar
Insulation resistance test and dielectric strength test
0.1 second
or more
0.1 second
or more
TimeTime
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Page 32
25
Table 10.1 Daily and Periodic Checks
-
-
Check
point
General
Main
circuit
Control
circuit
Protective
circuit
Check cycle
Check item Checking
Environment Check ambient temperature, relative humidity, and
concentration of dust, toxic gases, and oil mist.
Device status
Supply voltage
General (1) Insulation resistance test (between main circuit
Terminal board Check for damages and breaks. •› Visually No problem should be detected. – –
Smoothing capacitor
on the PC board
Resistor (1) Check for cracks and discoloration. •› (1) Visually (1) No problem should be detected. – –
Operation check Carry out the sequence protector test to check the
Component
check
(including
PC board)
General (1) Check for burnt smell and discoloration.
Capacitor (1) Check for electrolyte leaks and casing deformation. •› Visually
Check for abnormal vibration and noise from the device. •›
terminal and the grounding terminal)
(2) Check for loose screws (terminal bases, etc.).
(3) Check for overheated or burnt parts.
(4) Cleaning
(1) Check for electrolyte leaks.
(2) Check whether the capacitor is swollen.
operation of the protective and display circuits.
(2) Check for rust and corrosion.
Daily Periodic
•› Visually and audibly The ambient temperature should be -
•›
•›
•›
•›
•›
•›
•› Simulate the output of
•›
•›
Checking method Requirement
10°C to +50°C (not freezing).
The ambient relative humidity should be
20% to 90% (non-condensing).
No abnormal vibration and noise should
be detected.
(1) Tighten the
screws firmly.
(1) (2) Visually (1) (2) No problem should be detected. 5 years (Note) –
the inverter protection
circuit.
Visually
(1) (2): No problem should be detected.
Tightening torques (in N.m)
M3: 0.6 to 0.9 M8: 10 to 13.5
M4: 1.5 to 2.1 M10: 21 to 28
M5: 2.8 to 3.9
M6: 4.1 to 5.3
The circuits should work normally.
No problem should be detected. 5 years (Note) –
Typical part
replacement
timing
Thermometer,
–
– 500V meggar
– –
hygrometer, and
multi-meter
Testing tools
Note: The ambient temperature affects the service life of the capacitor. See Ambient Temperature vs. Capacitor Life (Appendix).
Page 33
11. PARTS ORDERING AND INQUIRY
When inquiring or ordering replacement parts, please provide the following information to your
local Hitachi distributor or service office:
(1) Model number
(2) Manufacturing number (MFG. No.)
(3) Symptom or details of the trouble (in detail)
If the label is hard to be read, report the external view or appearance of the replacement part and
a short explanation of the trouble, together with the ordering sheet.
It is recommended for you to have another product as an auxiliary device your work will not be
disrupted.
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Page 34
APPENDIX
Service life of capacitor
C)
°
Running time: Continuous (24 hours a day)
Duty ratio: 10% Ed
Duty ratio: 100% Ed (Continuous regeneration)
Service life
Appendix Figure 1 Ambient Temperature vs. Capacitor Life characteristics
The ambient temperature affects the service life of the aluminum electrolytic capacitor. (See
Appendix Figure 1.)
Periodically check the capacitor and make sure it is free from leaks, deformations, etc.
If the dynamic braking unit is frequently used in a hot location, the capacitor will quickly
deteriorate and consequently the service life of the dynamic braking unit may be shortened.
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