When Using The High-Duty Brake Resistor (Fr-Abr) - Mitsubishi Electric FR-A700 Instruction Manual

(14) If the machine must not be restarted when power is restored after a power failure, provide a magnetic contactor in the
inverter's input side and also make up a sequence which will not switch on the start signal.
If the start signal (start switch) remains on after a power failure, the inverter will automatically restart as soon as the
power is restored.
(15) Instructions for overload operation
When performing an operation of frequent start/stop with the inverter, rise/fall in the temperature of the transistor element
of the inverter will repeat due to a continuous flow of large current, shortening the life from thermal fatigue. Since thermal
fatigue is related to the amount of current, the life can be increased by reducing current at locked condition, starting
current, etc. Decreasing current may increase the life. However, decreasing current will result in insufficient torque and
the inverter may not start. Therefore, choose the inverter which has enough allowance for current (up to 2 rank larger in
capacity).
(16) Make sure that the specifications and rating match the system requirements.
(17) A motor with encoder is necessary for vector control. In addition, connect the encoder directly to the backlash-free motor
shaft. (An encoder is not necessary for real sensorless vector control.)

2.7 When using the high-duty brake resistor (FR-ABR)

• When the regenerative brake transistor is damaged, the wiring sequence as shown in the following diagrams is
recommended to prevent overheating and burnout of the brake resistor.
<Example 1>
MC Inverter
R/L1
Power
S/L2
Supply
T/L3
T
F
OFF
ON
MC
OCR
Contact
MC
Note that the built-in brake resistor need not be removed. The leads of the built-in brake resistor need not be
disconnected from the terminals.
*1Remove the jumper from across the PR-PX terminals of the inverter. *1 This disables (switches off) the built-in brake resistor. When you use the
11K or more inverter, you need not remove the jumper since that inverter does not have the PX terminals. (Refer to the instruction manual of
the inverter.)
*2Refer to the following table for the thermal relay model number and to the following diagram for connection. (When using the 11K or more,
always install a thermal relay.)
Power
High-duty Brake
Supply
Resistor
Voltage
FR-ABR-0.4K
FR-ABR-0.75K
FR-ABR-2.2K
FR-ABR-3.7K
200V FR-ABR-5.5K
FR-ABR-7.5K
FR-ABR-11K
FR-ABR-15K
FR-ABR-22K
FR-ABR-H0.4K
FR-ABR-H0.75K
FR-ABR-H1.5K
FR-ABR-H2.2K
FR-ABR-H3.7K
400V
FR-ABR-H5.5K
FR-ABR-H7.5K
FR-ABR-H11K
FR-ABR-H15K
FR-ABR-H22K
Thermal High-duty
relay brake resistor
(OCR)(*2) (FR-ABR)
P/+
R
PX
PR
Disconnect jumper. (*1)
Thermal Relay Type
(Mitsubishi product)
TH-N20CXHZ-0.7A
TH-N20CXHZ-1.3A
TH-N20CXHZ-2.1A
TH-N20CXHZ-3.6A
TH-N20CXHZ-5A
TH-N20CXHZ-6.6A
TH-N20CXHZ-11A
TH-N20CXHZ-11A
TH-N60-22A
TH-N20CXHZ-0.24A
TH-N20CXHZ-0.35A
TH-N20CXHZ-0.9A
TH-N20CXHZ-1.3A
TH-N20CXHZ-2.1A
TH-N20CXHZ-2.5A
TH-N20CXHZ-3.6A
TH-N20CXHZ-6.6A
TH-N20CXHZ-6.6A
TH-N20-9A
When using the high-duty brake
<Example 2>
Inverter
MC
R/L1
Power
S/L2
Supply
T/L3
T
F
B
OFF
ON
MC C
OCR
MC Contact
Contact Rating
AC110V 5A,
AC220V 2A(AC-11 class)
DC110V 0.5A,
DC220V 0.25A(DC-11 class)
resistor (FR-ABR)
Thermal High-duty
relay brake resistor
(OCR)(*2) (FR-ABR)
P/+
R
PX
PR
Disconnect jumper. (*1)
1/L 5/L
1 3
TH-N20
2/T 6/T
1 3
To the inverter To the ABR
P/+ terminal
37
2