2.10.2 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 OFF ON OCR contact MC T *2 MC GRZG type discharging resistor MCCB MC OCR R R *6 Three-phase AC power supply R/L1 S/L2 T/L3 U V W Motor M External thermal relay *5 *1 PR PX *3 Inverter PR *4 FR-BU2 P/+ A B C P/+ N/- N/- BUE SD *1 *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 Be sure to remove the jumper across terminals PR and PX when using the FR-BU2 with the inverter of FR-A820-00490(7.5K) or lower, or FR- A840-00250(7.5K) or lower. *4 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. *5 It is recommended to install an external thermal relay to prevent overheat of the discharging resistor. *6 For the connection method of the discharging resistor, refer to the Instruction Manual of the FR-BU2.
Recommended external thermal relay 1/L 1 5/L 3 To the brake unit terminal P/+ To a resistor 2/T 1 6/T 3 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). 102 2.
INSTALLATION AND WIRING 2.10 Connection of stand-alone option units 10 m or less brake unit Discharging resistor Recommended external thermal relay FR-BU2-1.5K GZG 300W-50Ω (one) TH-T25 1.3A FR-BU2-3.7K GRZG 200-10Ω (three in series) TH-T25 3.6A FR-BU2-7.5K GRZG 300-5Ω (four in series) TH-T25 6.6A FR-BU2-15K GRZG 400-2Ω (six in series) TH-T25 11A FR-BU2-H7.5K GRZG 200-10Ω (six in series) TH-T25 3.6A FR-BU2-H15K GRZG 300-5Ω (eight in series) TH-T25 6.6A FR-BU2-H30K GRZG 400-2Ω (twelve in series) TH-T25 11A NOTE