Dynamic Braking Resistor Wire/Cable Specifications - Toshiba G3+ PACK Operation Manual Addendum

Dynamic Braking Resistor Wire/Cable
Specifications
When using a Dynamic Braking Resistor (DBR), use thermal protection and an input contactor that
will open the input 3-phase power circuit to the ASD in the event that a DBR over-temperature
condition occurs. In the event of a power source over-voltage condition or an ASD failure the input
contactor will prevent hazardous DBR temperatures.
Because the heat generated by the DBR will affect the cooling capacity of the heatsink, the resistor pack
should be mounted above or to the side of the ASD — Never below the ASD. Maintain a minimum of
six inches between the resistor pack and the ASD unit.
Heavy duty DBRs should be wired using the same gauge wire as the motor leads. Light duty DBRs may
use one wire size smaller (AWG) than the motor leads.
The total wire length from the ASD to the DBR should not exceed ten feet.
If EMI/RFI noise is of concern, the DBR wiring should be three-core screened cable. The screen should
connect to the ASD enclosure and the resistor enclosure.
18 G3+ Pack Addendum