Rockwell Automation AK DBU - Dynamic Braking Unit 600/690 VAC - Manual (Page 18)

1-6 Installation/Wiring
Connection leads between the DBU and the Brake Resistor (R)
The cable length between the DBU and the Brake Resistor must not
exceed 30 meters, but the limiting factor for this connection is the time
constant of the brake resistor (Ratio of Inductance to Resistance).
See
Brake Resistor Specifications on page A-4
The inductance of the cables or leads can be reduced by bundling single
leads or using multi core (EMC shielded) cable.
To connect the brake resistors, heat-resistant cables and cable sockets
must be used (min. 90°C). Brake resistor cable selection should be based
on the maximum mean rms braking current of the DBU. See page
A-1 .
For Max./Min. cable cross sections (mm
2
and AWG) and tightening
torque see Table 1.B .
Cooling Fan Supply Voltage
A 115 VAC (50/60 Hz, 0.2A) customer supplied power supply is
required for the DBU cooling fans. The 115V AC Power source should
be connected between terminals (0) and (115) located on the fan unit.
See
Figure 1.3 and Figure 1.4 .