External Braking Resistor With Overheat Protection; Figure 31: External Braking Resistor With Overheat Protection - KEB COMBIVERT F5 Instructions For Use Manual

eLecTrIcAL INSTALLATION

5.10.2 external braking resistor with overheat protection

This circuit provides an indirect protection with defective braking transistor.
•
•
The regenerative operation is secured as follows.
•
•
•
OH1
OH2
S1
K1
Legend
K1 Coupling relay switching on / off
S1 Switch on U4
Line contactor with auxiliary contacts „Permissible cable cross-sections and tightening torques of the
K3
terminals"
Figure 31: External braking resistor with overheat protection
In case of failure the brake resistor overheats and opens the OH terminals.
These open the hold circuit of the input contactor and switches off input voltage.
The opening of the auxiliary contacts of K3 triggers an error in the drive converter.
The input I2 must be programmed and inverted to "external error".
Automatic restarting after cooling of the braking resistor is prevented by the self-hold-
ing circuit of K3.
PTc / KTy evaluation
If the PTC / KTY evaluation at terminals T1A, T2A / T1B, T2B are not used,
these can be used instead of the programmable input.The temperature input
must be operated in PTC mode.
-R1
14
-K3
13
I2
R /R
A B
F5/F6
-U4
+
0V
U4 COMBIVERT F5 / F6
R1 Braking resistor with temperature switch
+ 24V DC
-
59