Fuji Electric BU22-2C User manual

Instruction Manual
DB Unit
Braking unit
200V class 11-22kW / BU22-2C
400V class 11-22kW / BU22-4C
CAUTION
■ Deliver this instruction manual without fail to
those who actually operate the equipment.
■ Read this operation manual and understand
the description before installing, connecting
(wiring), operating or performing
maintenance and inspection of the braking
unit.
■ Keep this instruction manual in a safe place
until the braking unit is discarded.
■ The product is subject to change without
prior notice.
Fuji Electric FA Components & Systems Co., Ltd. INR-SI47-0845a-E

Introduction
Thank you for purchasing our braking unit. This equipment discharges the braking force in braking
operation of Fuji’s general purpose inverter to a resistor. For applicable inverter models, refer to
Table A.
Before starting operation, read through this operation manual to understand the handling method
and operate correctly. An incorrect handling will obstruct correct operation or cause a reduced life or
failure. Keep the instruction manual in a safe place even after operation is started.
This operation manual does not cover the inverter handling. For the handling of the inverter, refer to
the applicable inverter instruction manual.
Table A. Applicable Inverter Models
Class Model
200V General-purpose
inverter FRENIC5000 G11S/P11S Series
FRENIC5000 G11UD Series
400V General-purpose
inverter FRENIC5000 G11S/P11S Series
FRENIC5000 G11UD Series
Safety Precautions
Read through this operation manual carefully before installing, connecting, (wiring), operating or
performing maintenance and inspection for correct usage.
Be familiar with all the devices, safety information, and cautionary items.
In this operation manual, safety precautions are described under the following titles.
WARNING
Wrong handling may cause danger possibly accompanying deaths or serious
injuries.
CAUTION
Wrong handling may cause danger possibly accompanying minor or
moderate injuries or material losses.
Precautions described in the caution category may cause serious results in some circumstances.
Both precautions are important; observe the description without fail.
Application WARNING
・ This unit discharges the braking force in braking operation of Fuji’s general purpose inverter to a
resistor. It cannot be used for other applications.
Risk of fire
・ This unit cannot be used for applications directly related to personal danger such as a life
support system.
・ This product is manufactured under strict quality control. However, if it is used for equipment
where serious accidents or losses may occur in case of failure of this product, install a safety
device.
Risk of accident

Installation WARNING
・ Install to nonflammable matter such as metals.
Risk of fire
・ Do not place flammable matter nearby.
Risk of fire
・ Contain the unit inside a distribution panel or the like so that it cannot be touched easily.
Risk of electric shock or accident
・ Use bolts of the specified sizes for installation without fail.
Risk of accident or injuries
CAUTION
・ Do not hold the front cover when carrying.
Risk of drop and injuries
・ Do not allow lint, paper, wood dust, other dust, metallic dust or other types of foreign matter to
intrude in the braking unit or do not allow them to be stuck on the heat sink.
Risk of fire or accident
・ Do not install and operate the braking unit if it is damaged or some parts are missing.
Risk of injuries
Wiring WARNING
・ Use the designated size for wiring cables.
Risk of fire
・ Do not make a mistake in the polarity (+, -) of the DC terminals (P(+), N(-)) and inverter
connection terminals.
Risk of fire
・ Be sure to connect the grounding cable.
Risk of electric shock or fire
・ Have the wiring work conducted by a qualified electrician.
Risk of electric shock
・ Check that the power is turned off (opened).
Risk of electric shock
・ Be sure to install the main body first before starting wiring.
Risk of electric shock or injuries
CAUTION
・ Check that the rated voltage of the product conforms to the rated voltage of the inverter.
Risk of injuries
・ Do not connect the braking resistor directly to the DC terminals (P(+), N(-)).
Risk of fire
・ Noise is generated from the unit and wiring. Be careful of malfunction of nearby sensors or
devices.
Risk of accident

Operation WARNING
・ Be sure to install the surface cover before turning the power on (closing). Do not remove the
cover while the power is turned on.
Risk of electric shock
・ Do not touch the terminals of the braking unit while the power is supplied to the inverter or even if
the unit is stopped.
Risk of electric shock
CAUTION
・ Do not use the main circuit ON/OFF switch to start or stop the inverter.
Risk of failure
・ Do not touch the heat sink and braking resistor because they become hot.
Risk of burns
・ The braking function of this unit does not guarantee mechanical suspension.
Risk of injuries
Maintenance, inspection and parts replacement
WARNING
・ Turn the power off (open) and wait for at least 10 minutes before starting inspection.
Check that the charge lamp is unlit and check that the DC voltage across the P(+) and N(-)
terminals is 25V or lower.
Risk of electric shock
・ Do not perform maintenance, inspection or parts replacement if you are not the appointed
person.
Take off metallic objects such as watches and rings before starting work.
Use insulated tools.
Risk of electric shock or injuries
Disposal CAUTION
・ When discarding the product, handle it as an industrial waste.
Risk of injuries
Others WARNING
・ Never remodel.
Risk of electric shock or injuries
General Precautions
Schematic drawings found in this operation manual may indicate a view without covers or safety
shields for explanation of details.
When operating the product, restore the covers and shields and observe the operation manual.

Table of contents
1. Before Starting Operation
1-1 Shipment Inspection ··································· 1-1
1-2 Appearance of Product······························· 1-1
1-3 Handling the Product ·································· 1-2
1-4 Transportation············································· 1-2
1-5 Storage························································ 1-2
2. Installation and Connection······································ 2-1
2-1 Operating Environment······························· 2-1
2-2 Installation Method······································ 2-1
2-3 Connection·················································· 2-2
2-3-1 Basic Connection ······························ 2-2
2-3-2 Connection of Main
Circuit and Grounding Terminal········ 2-4
2-3-3 Connection of Control Terminal ········ 2-4
2-3-4 Terminal Layout································· 2-5
2-3-5 Standard applied device
and cable size··································· 2-5
3. Operation·································································· 3-1
3-1 Inspection and Preparation
Before Operation········································· 3-1
4. Protective Action ······················································ 4-1
4-1 Protective Action········································· 4-1
4-2 Alarm Reset ················································ 4-1
5. Maintenance and Inspection ··································· 5-1
5-1 Daily inspection··········································· 5-1
5-2 Periodic Inspection······································ 5-1
5-3 Insulation Test············································· 5-2
5-4 Replacement Parts ····································· 5-3
5-5 Inquiry About Product and Guarantee········ 5-3
6. Specifications ··························································· 6-1
6-1 Standard Specifications······························ 6-1
6-1-1 Braking Unit······································· 6-1
6-1-2 Braking Resistor································ 6-2
6-2 External Dimensions··································· 6-3
7. Optional Fan····························································· 7-1
7-1 Specifications of Optional Fan···················· 7-1
7-2 Installation of Optional Fan Unit·················· 7-1
7-2-1 Installation ······································· 7-1
7-2-2 Optional Fan Wiring··························· 7-1
7-3 External Dimensions··································· 7-2

1-1
1 Before Starting Operation
1-1 Shipment Inspection
Unpack and check the following items.
If you have any question or trou le, contact
the store of purchase or nearest Fuji’s sales
office.
(1) Refer to the rating nameplate to check if
the delivered product is the ordered one.
TYPE : Type of raking unit
SOURCE : Power source rating
OUTPUT : Output rating
SER.No. : Serial num er
(2) Check if there are any missing or roken parts or dents or other transportation damage in
the cover and main ody.
(3) The raking resistor is not attached. Prepare a suita le resistor matching the
specifications separately.
1-2 Appearance of Product
Fig. 1-2-1. Appearance of Product Fig. 1-2-2
3 1 1234R0001
Serial manufacturing lot num er
Manufacturing month: 1 to 9 → January to Septem er
X → Octo er. Y → Novem er. Z → Decem er
Manufacturing year: The last one digit of year. 3 → Year 2003
Fig. 1-1-1. Rating Nameplate
BU 22 - 2 C
Standard series : C
Power source voltage class of the inverter: 2 → 200V class. 4 → 400V class
Standard applied motor capacity of inverter : 22→22kW
Product type

1-2
1-3 Handling the Product
(1) Removal of terminal cover
Loosen the mounting screws of the terminal cover and, while holding the terminal cover,
remove it as shown in Fig. 1-3-1
Fig. 1-3-1. Removal of Terminal Cover and Surface Cover
1-4 Transportation
Be sure to hold the main ody when transporting.
If the cover or parts are held, there is danger of raking or dropping.
1-5 Storage
Store the product in an environment specified in Ta le 1-5-1.
Ta le 1-5-1 Storage Environment
Item Specifica
tion
Am ient
temperature –10 ~ +50°C
Storage
temperature NOTE1
–25 ~ +65°C
Relative humidity 5 ~ 95% Note 2
Place free from condensation or icing caused y
a rupt temperature changes
Atmosphere Free from dust, direct sunshine, corrosive or flamma le gases, oil mist,
vapor, water drops or vi ration. Free from much salt
Note 1: The storage temperature indicates the temperature in short period such as during
transportation.
Note 2: Even if the temperature satisfies the specification values, condensation or icing
occurs at places with steep temperature changes. Avoid such places.
(1) Do not place directly on the floor.
(2) If the am ient atmosphere is adverse, pack the unit with a vinyl sheet or the like to store.
(3) If moisture may cause ill effects, place a drying agent such as silica gel inside the package
efore packing as descri ed at (2).

2-1
2 Installation and Connection
2-1 Operating Environment
Install the unit in the environment shown in Table 2-1-1.
Table 2-1-1. Operating Environment
Item Specification
Site Indoors
mbient
temperature
–10 ~ +50℃
Relative
humidity
5 ~ 95% (Without condensation)
tmosphere Free from dust, direct sunshine, corrosive gases, oil mist, vapor or water
drops.
Free from much salt.
Free from condensation caused by abrupt temperature changes
ltitude 1,000m maximum
(If 1,000m is exceeded, reduce the inverter output according to the inverter
operation manual.)
Vibration 3.0mm at 2～9Hz, 9.8m/s2 at 10～20Hz, 4.9m/s2 at 20～55Hz, 1.0m/s2 at 55
～200Hz
2-2 Installation Method
(1) Install the braking unit on a solid structure
securely with bolts and vertically so that the label
characters are seen in front.
(2) The braking unit generates heat during
operation. Reserve space shown in Fig. 2-2-1 to
assure passage of cooling air. Because the
generating heat is radiated above, do not install
below a device susceptible to heat.
(3) The temperature of the heat sink rises up to
about 90°C during operation of the braking unit.
The material of the mounting face at the back of
the braking unit must bear the temperature rise
with a sufficient margin.
W RNING
Install on nonflammable matter such as metals.
Risk of fire
(4) When the unit is installed inside the control panel or the like, take sufficient care of
ventilation so that the ambient temperature of the braking unit does not exceed the
specification value. Do not house in an ill-ventilated small airtight container.
(5) When two or more inverters and the braking unit are housed in the same equipment or
inside the control panel, side-to-side installation is recommended to reduce the mutual
effects of heat. If the units must be installed vertically for unavoidable reason, install a
partition plate or the like so that the heat generating at the lower unit does not give ill
effects on the upper unit.
C UTION
Do not allow lint, paper, wood dust, other dust, metallic dust or other
foreign matter to intrude inside the unit or do not allow them to be stuck on
the heat sink.
Risk of fire or accident
D B U n it
本 体
上
下
右左
1 0 0 m m
1 0 0 m m
5 0 m m
以 上
5 0 m m
以 上
Fig. 2-2-1
Left
50mm
minimum
Up
Right
Down
50mm
minimum
Main body

2-2
2-3 Connection
fter the terminal cover is removed, each terminal block becomes visible (see Fig. 2-3-1).
Take care of the following items and connect without mistakes.
2-3-1 Basic Connection
(1) Connect the DC link connection terminals (P(+), N(-)) with the DC link circuit terminals
(P(+), N(-)) of the inverter. The unit and the inverter will be damaged if the polarity is
incorrect or other terminals are connected. s well, check that the source voltage
conforms to the specification of the connected inverter.
(2) Be sure to ground the grounding terminal to avoid disasters such as electric shock
and fire and to reduce noise.
(3) Use crimp terminals with high connection reliability for the connection between the
terminal and cable.
(4) fter finishing connection (wiring) work, check the following.
a. Correct connection
b. Failure to connect
c. Short circuit or ground fault of terminals and cables
(5) To change connection after power application
fter the power is turned off, it takes time until the smoothing capacitor in the DC
circuit of the main circuit is discharged. Before starting work, wait until the charge
lamp is unlit and check that the DC voltage has dropped to a safe voltage (25Vdc or
lower) with a multimeter or the like to avoid danger. In addition, short circuiting may
cause sparks if there is a remaining voltage (charge). Wait until the voltage becomes
low.
W RNING
・ Be sure to connect the grounding cable.
Risk of electric shock or fire
・ Have wiring work done by a qualified electrician.
・ Check that the power is turned off (opened) before starting work.
Risk of electric shock
Inside unit
Fig. 2-3-1 Inside unit

2-3
■
■■
■Basic Connection Diagram
インバータ 制動ユニット 制動抵抗器
P(+)R
P(+)
N(-)
DB
G
G1 2
1 2
ｵﾌﾟｼｮﾝ
ﾌｧﾝ*4
P(+)
N(-)
外部ｱﾗｰﾑ入力(*1)
CM
制御回路
主回路
P1
Ｍ
線長５ｍ以下
P
DB
(*3)
+
(*2) (*3)
線長５ｍ以下
G
Fig. 2-3-2
(*1) The inverter may allow arbitrary assignment of digital input terminals.
Use the function setting of the inverter to select external alarm input.
(*2) Connect the batch alarm output of the braking unit and braking resistor to the
external alarm input of the inverter and build a sequence that opens the
electromagnetic contactor with the batch alarm output of the inverter.
(*3) Be sure to twist or route in close contact (in parallel) the two cables connecting
the inverter with the braking unit and that connecting the braking unit with the
braking resistor.
(*4) The optional fan needs separate power supply. The source voltage varies
according to the optional fan to be used. BU-F1S (single-phase 100Vac),
BU-F2S (single-phase 200Vac)
Inverter
Cable
length: 5m or
Braking unit
Braking
resistor
Cable length:
5m or less
Main circuit
Control circuit
External alarm input (*1)
Optional fan*4

2-4
2-3-2 Connection of Main Circuit and Grounding Terminal
Table 2-3-1. Function of Main Circuit Terminals and Grounding Terminal
Terminal
symbol Terminal name Description
P(+), N(-) DC link connection terminal The DC link circuit voltage of the inverter
is connected.
P(+)R, DB Terminals for connecting
braking resistor The braking resistor is connected.
G For grounding the braking
unit
Connection terminal for chassis (case) of
the braking unit
(1) DC link connection terminal (P(+), N(-))
1) Connect the DC link circuit terminals P(+) and N(-) of the inverter with the terminals P(+)
and N(-) of the braking unit.
2) rrange units so that the wiring length is within 5m. Twist or route in close contact (in
parallel) the two cables.
3) Do not connect to the C power supply.
(2) Terminal for connection of braking resistor (P(+)R, DB)
1) Connect terminal P and DB of the braking resistor to terminal P(+)R and DB of the
braking unit.
2) rrange units so that the wiring length is within 5m. Twist or route in close contact (in
parallel) the two cables.
3) Do not connect to the C power supply.
(3) Unit grounding terminal ( G)
Be sure to ground unit grounding terminal ( G) for safety and noise reduction. The Electric
Equipment Engineering Standard requires grounding work of the metallic frame of electric
devices for the prevention of electric shock, fire and other disasters.
Follow the procedure below to connect.
1) Connect to class D grounding electrode (200V class) or class C grounding electrode
(400V class) according to Electric Equipment Engineering Standard.
2) Connect a thick and short cable between the grounding terminal and the grounding
electrode exclusively provided for the inverter system.
Table 2-3-2
Voltage class Type of grounding work Grounding resistance
200V Class D grounding work
100Ω maximum
400V Class C grounding work
10Ω maximum
C UTION
・ Do not connect the C power supply to DC link terminals (P(+), N(-)).
Risk of accident
・ Do not connect the braking resistor directly to the DC link terminals (P(+), N(-)).
・ Check if the specifications of the product match the connected inverter.
・ The braking resistor may generate excessive heat if the braking unit is broken.
Build a sequence for shutting off the power supply of the inverter input upon an alarm
signal.
Risk of fire
2-3-3 Connection of Control Terminal
The function of the control circuit terminal is described in Table 2-3-3.
Table 2-3-3
Terminal
symbol
Terminal name Description
1, 2 Braking unit batch alarm
output
IGBT for driving the DB and overheat generation of the
braking resistor are output.
(1) Braking unit batch alarm output (1, 2)
1) Connect the inverter’s contact input terminals assigned to external alarm input, to
the braking unit and braking resistor terminals in series in order of: 1  2  1  2.
If there is a short bar at the inverter’s target contact input terminal, remove it.
(2) Others
1) Route the control terminal cables as far away as possible from the main circuit
cables. Otherwise malfunction caused by noise may result.
2) Tie the control cables inside units so that they do not make contact with live parts of
the main circuit (such as the terminal block of the main circuit).

2-5
W RNING
• Because the sheath of the general control cable is not reinforced insulation, a
high voltage of the main circuit may intrude the control signal when the
insulating sheath is broken due to some reason.
Risk of electric shock
C UTION
• Noise is generated from the inverter, motor, cable and so on. Take care of
malfunction of surrounding sensors and devices.
Risk of accident
2-3-4 Terminal Layout
BU22-2C,4C
Screw size M5 Screw size M3
Screw size M4
2-3-5 Standard applied device and cable size
Braking unit Braking resistor Tightening torque (N･m)
Recommended
cable size
(mm2) (Note 1)
Voltage
pplied
motor
(kW)
Model Qty Model Resistance
( Ω )
Qty Main circuit
Ground
ing
Control
DB circuit
(P(+), N(-),
P(+)R, DB)
Ground
( G)
Control
11 1
DB11-2C
DB11-2 10 1
15 1
DB15-2C
DB15-2 8.6 1
DB22-2C 5.8
18.5 1
DB18.5-2 6.8 1
200V
22
BU22-2C
1
DB22-2C
DB22-2 5.8 1
2 1.8 0.5
2 Note 2
3.5 Note 3 1.25
11 1
DB11-4C
DB11-4 40 1
15 1
DB15-4C
DB15-4 34.4
1
DB22-4C 22
18.5 １
DB18.5-4 27 1
400V
22
BU22-4C
１
DB22-4C
DB22-4 22 1
2 1.8 0.5 2 1.25
Note 1: The cable to be used is 600V HIV insulated
cable with allowable temperature 75°C.
Selection is made on assumption that the
ambient temperature is 50°C.
Note 2: The operation ratio is considered in 10%ED.
Note 3: The operation ratio is considered in 30%ED.
G
２
１
DB
P(+)R
P(+)
N(-)

3-1
3 Operation
3-1 Inspection and Preparation Before Operation
Inspect the following items before starting
operation.
(1) Check for correct connection.
ake care of the following points among
all.
a. Check if the DC link connection terminals
P(+) and N(-) and braking resistor
connection terminals P(+)R and DB are not
connected to the AC power supply.
b. Check if the braking resistor connection
terminals P(+)R and DB are not connected
with the DC link voltage.
c. Check if the grounding terminal is securely
grounded.
(2) Check if there is not a short circuit or ground fault across terminals or bare live parts.
(3) Check if terminals, connectors and screws are not loose.
After turning the power on, check the following.
(1) Check if the inverter doesn’t show an external failure alarm.
(2) Check if the fan rotates (for models with optional fan).
WARNING
• Be sure to install the surface cover before turning the power on
(closing). Do not remove the cover while the power is ON.
Risk of electric shock
P(+)
N(
-
)
P(+)R
DB
P(+)
N(-) P
DB
Fig. 3-1-1. Braking Unit Connection Diagram
G
Braking unit
Inverter
Braking
resistor

4-1
4 Protective Action
4-1 Protective Action
If a fault shown in Table 4-1 occurs, the braking unit stops the DB drive signal and issues a
batch alar signal at ter inals 1 and 2 (the batch alar signal does not have a eans to
discri inate the description of the alar ).
This alar signal causes to actuate the protective function of the inverter to trip, and an
external alar is displayed on the keypad panel of the inverter while the otor coasts to
stop.
Because the braking resistor ay be excessively overheated upon failure of the braking
unit, build a sequence to shut off the power upon activation of a protective function of the
inverter.
Table 4-1
Alar Description
Overheated
heat sink
The te perature of the heat sink is high because operation is at a
braking fr
equency exceeding the specification li it, the a bient
te perature is too high, or the heat sink is clogged.
Overheated
braking resistor
The te perature of the braking resistor is high because the operation
frequency of the braking resistor is too high.
In addition, the fuse in the braking unit prevents secondary breakage by blown out when
the internal circuit is short or da aged. Regenerated inverter ay have OU trip with it
blown out.
4-2 Alar Reset
If the inverter has tripped, re ove the cause and reset the inverter according to the instruction
described in the inverter operation anual. When resetting, turn the inverter operation
co and off. If the operation co and is on, operation will be started after the inverter is
reset.
WARNING
If the inverter is reset fro an alar with the operation signal turned on,
operation will start suddenly. Check that the operation signal is turned off
before resetting.
Risk of accident

5-1
5 Maintenance and Inspection
Perform daily inspection and periodic inspection to avoid failure and maintain reliable operation over
a long period. Take care of the following items when working.
5-1 aily inspection
Visually check for faults in operation state without removing cover or the like, while the power
is turned on. Regular inspection includes the following criteria.
(1) Check if the expected performance (satisfying the standard specifications) is obtained.
(2) Check if the surrounding environment satisfies the standard specifications.
(3) Check if there is any abnormal noise, excessive vibration or malodor.
(4) Check if there are traces of overheat or discoloration.
5-2 Periodic Inspection
Stop the operation and turn the power off and remove the surface cover to perform periodic
inspection. It takes time after the power is turned off until the smoothing capacitor at the C
part of the main circuit is discharged. To avoid danger, wait until the CHARGE lamp is unlit
and check that the C voltage has dropped to a safe value (25V C or lower), using a
multimeter or the like.
WARNING
• Turn the power off (open) and wait for at least five minutes. Further, check
that the CHARGE lamp is unlit and measure the C voltage across terminals
P(+) and N(-) to check if the measurement is 25V C or lower.
Risk of electric shock
• o not perform maintenance and inspection or parts replacement unless you
are the appointed person.
Take off metallic objects (such as watches and rings) before starting work.
Use insulated tools.
Never remodel.
Risk of electric shock or injuries
Table 5-2-1. Periodic Inspection List
Inspection point Inspection item Inspection method Judgment criteria
Check the ambient temperature, humidity, vibration,
and atmosphere (presence / absence of dust, gas, oil
mist, water drops).
Visually check and measure
with measuring instruments.
The standard
specification must be
satisfied.
Surrounding
environment
Check if foreign matter such as a tool or dangerous
matter is left nearby.
Visual inspection Not left.
Voltage
Check if the voltage of the main circuit and control
circuit is correct.
Measure using a multimeter
or the like.
The standard
specification value must
be satisfied.
Check if there is abnormal noise or excessive
vibration.
Visual or auditory inspection No fault
Check if bolts (tightened parts) are not loose. Retighten. No fault
Structural parts
such as frame
and cover
Check for deformation and breakage.
Check for discoloration caused by overheat.
Check for stuck dirt or dust.
Visual inspection No fault
Check if bolts are not loose or missing. Retighten. No fault
Common
Check if devices and insulating matter are deformed,
cracked, broken, or discolored due to overheat or
deterioration.
Check for stuck dirt or dust.
Visual inspection
No fault
Note: A discolored bus
bar does not indicate a
problem in its
characteristics.
Conductors
and cables
Check if the conductor is discolored or deformed due
to overheat.
Check if the sheath of the cable is broken, cracked or
discolored.
Visual inspection No fault
Terminal
block
Check for breakage. Visual inspection No fault
Smoothing
capacitor
Check for liquid leakage, discoloration, cracks and
swollen case.
Check if the safety valve protrudes or the valve is
swollen excessively.
Visual inspection No fault
Check for malodor caused by overheat and cracked
insulators.
Smelling or visual inspection No fault
Main circuit
Resistor
Check for a broken wire.
Visually check or disconnect
either terminal and measure
with a multimeter.
Within +/-10% of
displayed resistance

5-2
(Cont’d)
Control circuit
Control
printed
board and
connectors
Check if screws and connectors are not loose.
Check for malodor and discoloration.
Check for cracks, breakage, deformation and
excessive rust.
Check the capacitors for liquid leakage and traces of
deformation.
Retighten.
Smelling or visual inspection
Visual inspection
No fault
Check for abnormal noise and excessive vibration.
Auditory or visual
inspection. Turn by hand.
Turn the power off without
fail.
Smooth rotation
Check for loose bolts. Retighten. No fault
Cooling fan
Check for discoloration caused by overheat. Visual inspection No fault
Cooling system
Ventilation
path
Check if the heat sink or suction or exhaust ports are
clogged or if foreign matter is stuck.
Visual inspection No fault
Note: Wipe off dirt using chemically neutral cleaning cloth. Suck duct with a vacuum cleaner.
5-3 Insulation Test
The insulation test is conducted before shipment from the factory. Avoid Megger test
whenever possible. When performing a Megger test for unavoidable reason, follow the
description below. A wrong test procedure may cause breakage of the product. Take
sufficient care.
The dielectric strength test, too, may cause breakage of the product if the test procedure is
wrong. Contact the store of purchase or our nearest sales office if a pressure resistance test
is necessary.
(1) Megger test of main circuit
1) Use a 500Vdc Megger and make sure to conduct with a discrete breaking unit. ( isconnect
both the main circuit cable and control cable)
2) Connect the main circuit terminals, using a common cable, as shown in Fig. 5-3-1.
3) The Megger test must be only across the common cable of the main circuit and ground
(terminal G).
4) 5MΩ or larger measurement displayed at Megger indicates a correct state. (Measurement
with a discrete unit)
＋
－
N(-) P(+) P(+)R DB
G
＋－
メガー
主回路コモン線
Fig. 5-3-1. Megger Test
(2) Insulation test of control circuit
o not perform a Megger test or dielectric strength test of the control circuit. For the control
circuit, prepare a high resistance range tester.
1) isconnect all external cables from the control circuit terminals.
2) Perform continuity test in respect to the ground. 1MΩ or larger measurement indicates the
correct state.
(3) External main circuit and sequence control circuit
isconnect all terminals from the unit so that the test voltage will not be applied to the unit.
Main circuit common cable
Megger

5-3
5-4 Replacement Parts
The life of the part depends of the type of the part.
The life of the part varies according to the surrounding environment and operating conditions.
It is recommended to replace parts while referring to Table 5-4-1 as a measure.
For the replacement method, contact the store of purchase or our nearest sales office.
Table 5-4-1. Replacement Parts
Part name Standard
replacement years
Replacement method and others
Cooling fan 3 years Replace with a new part.
Fuse 10 years Replace with a new part.
Other parts － etermine after investigation.
5-5 Inquiry About Product and Guarantee
(1) Notice for inquiry
For breakage of the product, uncertainties, failure or inquiries, contact the store of purchase
or our nearest sales office and let us know the following items.
a. Model of braking unit
b. SER NO. (production number)
c. Purchase timing
d. escription of inquiry (For example, point of breakage and scale of breakage,
uncertainties, failure symptom and circumstances, etc.)
(2) Guarantee of product
The guarantee period of the product is one year after purchase or 18 months since the month
and year of production specified on the nameplate, whichever comes earlier. However,
repairs will be charged in the following cases even if they are handled in the guarantee period.
1) Failure caused by handling errors or inadequate repair or remodeling
2) Operation in the range exceeding the standard specification value
3) Failure caused by dropping after delivery or damage caused by transportation
4) Failure caused by earthquake, fire, flood or wild wind, lightning, irregular voltage, or other acts
of God or secondary disaster

6-1
6 Specifications
6-1 Standard Specifications
6-1-1 Braking Unit
Class 200V 400V
Type BU22-2C BU22-4C
Minim m connecting
resistance (Ω) 5.8 22
Maxim m braking
power (kW) 22 22
Generating loss
(10%ED)(W) 20 15
Rated inp t c rrent
(Arms) 17 9
Mass (kg) 2 2
Braking torq e 150% (Instantaneo s maxim m torq e)
Operation ratio 10%ED (30%ED with optional fan) *1,*2
Braking time 10 sec.: period 100 sec. (30 sec. with optional fan) *1,*2
Action voltage (V) 390 780
Protective f nctions
• Blown f se
• Overheated heat sink
• Overheated braking
resistor
If one of fa lts listed on the left is sensed, IGBT inside
the braking nit is stopped.
Cooling method Self-cooling (forced air cooling with optional fan)
Operation site
Indoors
Altit de within 1000m
Witho t corrosive gas, d st or direct s nshine
Operating ambient
temperat re −10℃ ~ +50℃
*1) The operation ratio (%ED) and braking time are converted nder the deceleration braking
conditions as shown in the fig re below.
使用率 %ED=(T1/T0) X 100%
T1 : 制動時間(10秒)
T0 : 繰り返し周期(100秒)
T1 T1
T0
最大制動電力
制動電力
The rated c rrent is the effective c rrent in interval T0. T0 sho ld be less than
100s.
*2) For models with an optional fan, the operation ratio (%ED) is calc lated on ass mption that
the braking time (T1) is 30 seconds.
Braking power
Max. braking power
Operation ratio %ED=(T1/T0) × 100%
T1: Braking time (10 sec.)
T0: Repetition period (100 sec.)

6-2
6-1-2 Braking Resistor
1) Item s pporting 10%ED
200V class
Type
DB11-2C DB15-2C DB22-2C
Standard applied motor (kW) 11 15 22
Resistance ( Ω )
10 8.6 5.8
Max. capacity (kW) 11 15 22
Power-on c rrent (A) 9 11 17
Mass (kg) 10 13 22
400V class
Type
DB11-4C DB15-4C DB22-4C
Standard applied motor (kW) 11 15 22
Resistance ( Ω )
40 34.4 22
Max. capacity (kW) 11 15 22
Power-on c rrent (A) 5 6 9
Mass (kg) 11 14 21
Operation ratio 10%ED (Standard braking nit specifications; refer to *1)
Braking time 10 sec.: period 100 sec. (standard braking nit
specifications; refer to *1)
Operating ambient
temperat re −10℃ ~ +50℃
2) Item s pporting 5%ED
200V class
Type DB11-2 DB15-2 DB18.5-2 DB22-2
Standard applied motor (kW) 11 15 18.5 22
Resistance ( Ω )
10 8.6 6.8 5.8
Max. capacity (kW) 11 15 18.5 22
Power-on c rrent (A) 9 11 14 17
Mass (kg) 10 13 18 22
400V class
Type DB11-4 DB15-4 DB18.5-4 DB22-4
Standard applied motor (kW) 11 15 18.5 22
Resistance ( Ω )
40 34.4 27 22
Max. capacity (kW) 11 15 18.5 22
Power-on c rrent (A) 5 6 7 9
Mass (kg) 11 14 19 21
Operation ratio 10%ED(Standard braking nit specifications; refer to *1)
Braking time 10 sec.: period 100 sec. (standard braking nit
specifications; refer to *1)
Operating ambient
temperat re −10℃ ~ +50℃

6-3
6-2 External Dimensions