GE Industrial Solutions AF-650 GP General Purpose Drive - Manual (Page 22)

7 Installation
7.1.1 Brake Cable
Max. length [m]: 20 m screened cable.
The connection cable to the brake resistor is to be screened/armoured. Connect the screen/armouring to the conductive back plate at the frequency converter
and to the brake resistor metal cabinet by means of cable clamps.
NB!
Make sure that the brake resistors used are induction-free.
7.1.2 Protective Functions During Installation
When installing a brake resistor, every measure should be taken to avoid the risk of overloading, since a fire hazard may arise owing to the heat generated in the
heat resistor.
NB!
The brake resistor is to be fitted on a non-flammable material.
For protection of the installation, a thermal relay should be fitted that cuts off the frequency converter if the brake current becomes too high.
Calculate the brake current setting of the thermal relay as follows:
Itherm relay =
Pbrakeresistor max
Rbrakeresistor
R
br
is the current brake resistor value calculated in the section on "Calculation of brake resistor values". Illustration 7.1 shows an installation with a thermal relay.
AF-650 GP Brake Resistor Design Guide
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