3)
If brake resistors from other manufacturers are used, the characteristics must agree with the values
in the table.
Definitions
P
BRmax
The maximum braking capacity of the drive, when the length of the
braking pulse is at most 1 minute for each 10 minutes (
P
BRcont
× 1.5).
Must be more than the desired braking power.
P
BRcont
The continuous braking capacity of the drive
R
max
The maximum resistance value of the brake resistor that can provide
P
BRcont
R
min
The minimum permitted resistance value of the brake resistor
Selecting and routing the brake resistor cables
Use a shielded cable specified in the technical data.
￭
Minimizing electromagnetic interference
Make sure that the installation is compliant with the EMC requirements. Obey
these rules in order to minimize electromagnetic interference caused by the rapid
voltage and current changes in the resistor cables:
• Shield the brake resistor cable. Use shielded cable or a metallic enclosure. If
you use unshielded single-core cables, route them inside a cabinet that
efficiently suppresses the radiated emissions.
• Install the cables away from other cable routes.
• Avoid long parallel runs with other cables. The minimum parallel cabling
separation distance is 0.3 meters (1 ft).
• Cross the other cables at 90° angles.
• Keep the cable as short as possible in order to minimize the radiated emissions
and stress on the brake chopper. The longer the cable the greater the radiated
emissions, inductive load and voltage peaks over the IGBT semiconductors of
the brake chopper.
￭
Maximum cable length
The maximum length of the resistor cable(s) is 10 m (33 ft).
Selecting the installation location for the brake resistors
Protect the open (IP00) brake resistors against contact. Install the brake resistor
in a place where it cools effectively. Arrange the cooling of the resistor so that:
• no danger of overheating is caused to the resistor or nearby materials, and
156 Resistor braking
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