7. Options
7-7
(2) External DBR
If the braking torque or ED are insufficient with the above built-in resistor, provide an external resistor
wired as shown in Fig. 7-3. When using an external DBR, remove the built-in DBR. The resistance
value to obtain a 100% braking torque is shown in Table 7-4.
When using the external DBR resistor, is recommended the use of a thermal relay (76D), to prevent
burning as shown in Fig. 7-3
.
U
L +2
7 6D
E xte rna l D B R re sisto r
B u ilt-in D B R re sistor
L 1
L 1
M C
M C C B
VAT20 0 0
L 3
B
V
W
G
IM
M C
7 6D x
Fig. 7-3 DBR circuit
7-4-2 Units U2KN11K0S and larger, and U2KX11K0S and larger.
When carrying out dynamic braking with the unit U2KN11K0S and larger, or U2KX11K0S and larger, an
external dynamic braking unit must be used. Choose the unit according table 7-2
Connect the DBR unit as shown in Fig. 7-4. In some cases more than one unit can be wired in parallel,
check table 7-2.
U
L 1
L +1 L +2
L -
L +
L +
B
B
L -
L -
L 1
M C
M C C B
VAT 2000
L 3
V
W
IM
D B R R esisto r
M C C o ntrol
D B R U nit
U 2 K V 2 3D B U xx
D B R U nit N o 2
U 2 K V 2 3D B U xx
D B R R esisto r
M C
7 6 D
T H R Y
7 6 D
T H R Y
7 6 D
T H R Y
x
Fig. 7-4 DBR connection
