Connection Of The Brake Unit (Fr-Bu2) - Mitsubishi Electric 800 Series Instruction Manual

CAUTION
• If the resistor selection is incorrect, overcurrent may damage the inverter built-in brake transistor. Besides, the resistor
may be burned due to overheat.
• If the selection of the thermal relay is incorrect, the resistor may be burned due to overheat.
2.9.2

Connection of the brake unit (FR-BU2)

Connect the brake unit (FR-BU2(-H)) as follows to improve the braking capability during deceleration.
 Connection example with the GRZG type discharging resistor
MCCB
Three-phase AC
power supply
*1 When wiring, make sure to match the terminal symbols (P/+, N/-) on the inverter and on the brake unit (FR-BU2). (Incorrect connection will
damage the inverter and brake unit.)
*2 When the power supply is 400 V class, install a stepdown transformer.
*3 The wiring distance between the inverter, brake unit (FR-BU2) and discharging resistor must be within 5 m. When using twisted pair cable, use
the cable within 10 m.
*4 It is recommended to install an external thermal relay to prevent overheat of the discharging resistor.
*5 For the connection method of the discharging resistor, refer to the Instruction Manual of the FR-BU2.
• Recommended external thermal relay
brake unit
FR-BU2-1.5K
FR-BU2-3.7K
FR-BU2-7.5K
FR-BU2-H7.5K
NOTE
• Set "1" in Pr.0 Brake mode selection in the FR-BU2 to use a GRZG type discharging resistor.
• Do not remove the jumper across terminals P/+ and P1 except when connecting a DC reactor (FR-HEL).
84
2. Installation and Wiring
2.9 Connection of stand-alone option units
T ∗2
MC
U
R/L1
S/L2 V
W
T/L3
Inverter
P/+
∗1
N/-
10 m or less
Discharging resistor
GZG 300W-50Ω (one)
GRZG 200-10Ω (three in series)
GRZG 300-5Ω (four in series)
GRZG 200-10Ω (six in series)
ON OFF
MC
MC
GRZG type
∗5
discharging
OCR
resistor
R R
Motor
External thermal
∗4
relay
M
FR-BU2
∗3
PR
A
P/+ B
∗1
N/- C
BUE
SD
∗3
Recommended external
thermal relay
TH-T25 1.3A
TH-T25 3.6A
TH-T25 6.6A
TH-T25 3.6A
OCR
contact
1/L
1
2/T
1
To the brake
unit terminal P/+
5/L
3
6/T
3
To a resistor