Mitsubishi Electric FR-A700 Technical Manual page 505

(c) Use cables of the size below or larger size.
Cables applicable to the FR-BU/MT-BU5 brake
unit
Type
FR-BU-15K, FR-BR-15K
FR-BU-30K, FR-BR-30K
200V
FR-BU-55K, FR-BR-55K
FR-BU-H15K, FR-BR-
H15K
FR-BU-H30K, FR-BR-
H30K
FR-BU-H55K, FR-BR-
H55K
MT-BU5-H75K,
MT-BR5-H75K
400V
MT-BU5-H150K,
2 MT-BR5-H75K
MT-BU5-H220K,
3 MT-BR5-H75K
MT-BU5-H280K,
4 MT-BR5-H75K
MT-BU5-H375K,
5 MT-BR5-H75K
* Per one brake resistor
Cables applicable to the FR-BU2 brake unit
Discharging
brake unit Type resistor, Resistor
unit type
FR-BU2-1.5K
GZG 300W-50
GRZG 200-10
FR-BU2-3.7K
(three in series)
GRZG 300-5
FR-BU2-7.5K
(four in series)
GRZG 400-2
FR-BU2-15K
(six in series)
FR-BR-15K
FR-BU2-30K FR-BR-30K
FR-BR-55K
FR-BU2-55K
MT-BR5-55K
GRZG 200-10
FR-BU2-H7.5K
(six in series)
GRZG 300-5
FR-BU2-H15K
(eight in series)
FR-BR-H15K
GRZG 400-2
FR-BU2-H30K
(twelve in series)
FR-BR-H30K
FR-BU2-H55K FR-BR-H55K
FR-BU2-H75K MT-BR5-H75K
(d) If the transistors in the brake unit should
become faulty, the resistor can be unusually
hot, causing a fire. Therefore, install a
magnetic contactor on the inverter's input side
to configure a circuit so that a current is shut
off in case of fault.
Cable Size
2
3.5mm
2
5.5mm
2
14mm
2
3.5mm
2
3.5mm
2
5.5mm
2
14mm
*
2
14mm *
2
14mm
*
2
14mm *
2
14mm
*
Cable Size
Ω
2
(one)
2mm
Ω
2
2mm
Ω
2
3.5mm
Ω
2
3.5mm
2
5.5mm
2
14mm
Ω
2
2mm
Ω
2
3.5mm
Ω
2
3.5mm
2
5.5mm
2
14mm
539
(e) Connect the cables so that the terminal
symbols of the brake unit match those of the
inverter. When the FR-HEL power-factor
improving reactor has been connected, do not
connect the brake unit to terminal P1 to
protect the brake unit from damage.
Brake unit
P P
N N
Incorrect connection examples
3) Brake unit operation indications
Brake unit operation indication description
(FR-BU)
7-Segment LED
Indication
Indicates that the brake
(0)
unit is switched ON.
Indicates %ED during
(1 to A)
to brake operation.
Indicates a brake transistor
(E)
failure.
Indicates that the brake is
operated in excess of
(F)
*1
permissible %ED.
*1 When this operation indicator LED is lit to
indicate the excess of the permissible %ED,
the brake unit stops operating and therefore
the "overcurrent", "overvoltage" or other
protective function
activated. To resume operation, find and
remove its cause, then reset the inverter.
*2 By switching OFF the brake unit and making
a reset, the cumulative data of the brake duty
is cleared. Note that repeating reset many
times to perform operation will overheat the
resistor unit.
Indication of the brake unit operation (FR-BU2)
When [Pr.1 = 0] (initial value) in FR-BU2, 3rd digit of
the 3-digit LED indicates regeneration status.
Two segments flicker (rotate) at a time during
regeneration as shown below and rotate quickly
when regeneration amount is large. Another monitor
can be also displayed by the setting of [Pr.1] in FR-
BU2.
SELECTION
Brake unit
P1 P
FR-
P
HEL
N N
Description
of the inverter is
3