D.8.1 Brake component selection
When the VFD driving a high-inertia load decelerates or needs to decelerate abruptly, the motor runs in the power generation state and transmits the load-carrying energy to the DC circuit of the VFD, causing the bus voltage of the VFD to rise. If the bus voltage exceeds a specific value, the VFD reports an overvoltage fault. To prevent this from happening, you need to configure brake components.
| ² The design, installation, commissioning, and operation of the device must be performed by trained and qualified professionals. ² Follow all the "Warning" instructions during the operation. Otherwise, major physical injuries or property loss may be caused. ² Only qualified electricians are allowed to perform the wiring. Otherwise, damage to the VFD or brake components may be caused. ² Read the braking resistor or unit instructions carefully before connecting them to the VFD. ² Connect braking resistors only to the terminals PB and (+), and braking units only to the terminals (+) and (-). Do not connect them to other terminals. Otherwise, damage to the brake circuit and VFD and fire may be caused. |
| ² Connect the brake components to the VFD according to the wiring diagram. If the wiring is not properly performed, damage to the VFD or other devices may be caused. |
The VFD models of 037G/045P and lower are equipped with built-in braking units, and those of 045G/055P and higher need to be configured with external braking units. The VFD models of 045G/055P–055G/075P can be configured with optional built-in braking units, and after a built-in braking unit is configured, the VFD model code is added with a suffix "-B", for example, GD350A-045G/055P-4-B. Select braking resistors according to the specific requirements (such as the brake torque and brake usage requirements) on site.
Table D.5 Braking units for AC 3PH 380V(-15%)–440V(+10%)
VFD model | Braking unit model | Resistance applicable for 100% brake torque (Ω) | Dissipated power of braking resistor (kW) | Min. allowable brake resistance (Ω) | ||
10% brake usage | 50% brake usage | 80% brake usage | ||||
Built-in braking unit | 326 | 0.23 | 1.1 | 1.8 | 170 | |
GD350A-2R2G/003P-4 | 222 | 0.33 | 1.7 | 2.6 | 130 | |
GD350A-004G/5R5P-4 | 122 | 0.6 | 3 | 4.8 | 80 | |
GD350A-5R5G/7R5P-4 | 89 | 0.75 | 4.1 | 6.6 | 60 | |
GD350A-7R5G/011P-4 | 65 | 1.1 | 5.6 | 9 | 47 | |
GD350A-011G/015P-4 | 44 | 1.7 | 8.3 | 13.2 | 31 | |
GD350A-015G/018P-4 | 32 | 2 | 11 | 18 | 23 | |
GD350A-018G/022P-4 | 27 | 3 | 14 | 22 | 19 | |
GD350A-022G/030P-4 | 22 | 3 | 17 | 26 | 17 | |
GD350A-030G/037P-4 | 17 | 5 | 23 | 36 | 17 | |
GD350A-037G/045P-4 | 13 | 6 | 28 | 44 | 11.7 | |
GD350A-045G/055P-4 | DBU100H-110-4 | 10 | 7 | 34 | 54 | 6.4 |
GD350A-055G/075P-4 | 8 | 8 | 41 | 66 | ||
GD350A-075G-/090P4 | 6.5 | 11 | 56 | 90 | ||
GD350A-090G/110P-4 | DBU100H-160-4 | 5.4 | 14 | 68 | 108 | 4.4 |
GD350A-110G/132P-4 | 4.5 | 17 | 83 | 132 | ||
GD350A-132G/160P-4 | DBU100H-220-4 | 3.7 | 20 | 99 | 158 | 3.2 |
GD350A-160G/185P-4 | DBU100H-320-4 | 3.1 | 24 | 120 | 192 | 2.2 |
GD350A-185G/200P-4 | 2.8 | 28 | 139 | 222 | ||
GD350A-200G/220P-4 | 2.5 | 30 | 150 | 240 | ||
GD350A-220G/250P-4 | DBU100H-400-4 | 2.2 | 33 | 165 | 264 | 1.8 |
GD350A-250G/280P-4 | 2.0 | 38 | 188 | 300 | ||
GD350A-280G/315P-4 | Two sets DBU100H-320-4 | 3.6*2 | 21*2 | 105*2 | 168*2 | 2.2*2 |
GD350A-315G/355P-4 | 3.2*2 | 24*2 | 118*2 | 189*2 | ||
GD350A-355G/400P-4 | 2.8*2 | 27*2 | 132*2 | 210*2 | ||
GD350A-400G/450P-4 | 2.4*2 | 30*2 | 150*2 | 240*2 | ||
GD350A-450G/500P-4 | Two sets DBU100H-400-4 | 2.2*2 | 34*2 | 168*2 | 270*2 | 1.8*2 |
GD350-500G-4 | 2.0*2 | 38*2 | 186*2 | 300*2 | ||
Note:
l Select braking resistors according to the resistance and power data provided by our company.
l The braking resistor may increase the brake torque of the VFD. The preceding table describes the resistance and power for 100% brake torque, 10% brake usage, 50% brake usage, and 80% brake usage. You can select the braking system based on the actual operation conditions.
l When using an external braking unit, set the brake voltage class of the braking unit properly by referring to the manual of the dynamic braking unit. If the voltage class is set incorrectly, the VFD may not run properly.
| ² Do not use braking resistors whose resistance is lower than the specified minimum resistance. The VFD does not provide protection against overcurrent caused by resistors with low resistance. |
| ² In scenarios where brake is frequently implemented, that is, the brake usage is greater than 10%, you need to select a braking resistor with higher power as required by the operation conditions according to the preceding table. |
D.8.2 Braking resistor cable selection
Braking resistor cables need to be shielded cables.
D.8.3 Braking resistor installation
All resistors need to be installed in places with good cooling conditions.
| ² The materials near the braking resistor or braking unit must be non-flammable. The surface temperature of the resistor is high. Air flowing from the resistor is of hundreds of degrees Celsius. Prevent any materials from coming into contact with the resistor. |
Installation of braking resistors
| ² The VFD models of 037G/045P and lower need only external braking resistors. ² PB and (+) are the terminals for connecting braking resistors. |
Installation of braking units:
| ² (+) and (-) are the terminals for connecting braking units. ² The connection cables between the (+) and (-) terminals of the VFD and those of a braking unit must be shorter than 5 m, and the connection cables between the BR1 and BR2 terminals of a braking unit and the terminals of a braking resistor must be shorter than 10 m. |
The following figure shows the connection of one VFD to a dynamic braking unit.
