the required resistance value for the brake resistor, R
=
average power required during the braking cycle, P Rave
=
energy that the resistor should be able to dissipate,
E Rpulse =
As per the the Resistor types table above, for drive type 04A0 rating, the brake
resistor value should be between 99 and 285ohm. From the equation, the resistor
value can be up to 300ohm.
Hence, the ideal brake resistor value from the table can be selected as 285ohm.
Selecting and routing the brake resistor cables
Use a shielded cable with the conductor size specified in section
lead-through data for the power cables (page
Minimizing electromagnetic interference
Follow these rules in order to minimize electromagnetic interference caused by
the rapid current changes in the resistor cables:
•
Install the cables away from other cable routes.
•
Avoid long parallel runs with other cables. The minimum parallel cabling
separation distance should be 0.3 meters.
•
Cross the other cables at right angles.
•
Keep the cable as short as possible in order to minimize the radiated emissions
and stress on chopper IGBTs. The longer the cable the higher 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).
EMC compliance of the complete installation
Note: ABB has not verified that the EMC requirements are fulfilled with external
user-defined brake resistors and cabling. The EMC compliance of the complete
installation must be considered by the customer.
Placing the brake resistor
Install the resistors outside the drive in a place where they will cool.
Resistor braking 185
150).
Terminal and