WEG SCA06 User Manual - page 31
3
Installation and Connection
SCA06 | 3-13
NOTE!
Power factor correction capacitors are not needed at the input (L1, L2, L3) and must not be installed
at the output (U, V, W).
Power supply capacity
The SCA06 is suitable for a circuit capable of delivering not more than 30.000 symmetrical A
rms
(220 V) or
100.000 symmetrical A
rms
(380…480 V).
In case the SCA06 is installed in power lines with current capacity greater than the specified values (30.000 A
rms
and 100.000 A
rms
), it is necessary to use proper protection circuits, such as fuses or circuit breakers.
3.2.3.2 Rheostatic Braking
3.2.3.2.1 Dimensioning
In
Table 3.2 on page 3-13
are the recommended resistor values for each servo drive model, as well as the quantity
of resistors that can be connected. Lower resistance values (ohms) must not be used, because they damage the
braking. The data refer to the RF200 set offered by WEG.
Table 3.2: Quantity of braking resistors by servo drive
Servo drive
Recommended Resistor
Minimum Wiring
Model
Quantity
mm² (AWG)
SCA06B05P0D2
RF200 (30 Ω, 200 W, 2200 J)
01
1.5 (14)
SCA06C08P0T2
RF200 (30 Ω, 200 W, 2200 J)
02 in parallel (15 Ω)
2.5 (12)
SCA06D16P0T2
RF200 (30 Ω, 200 W, 2200 J)
03 in parallel (10 Ω)
4.0 (10)
SCA06D24P0T2
RF200 (30 Ω, 200 W, 2200 J)
03 in parallel (10 Ω)
4.0 (10)
SCA06C05P3T4
RF200 (30 Ω, 200 W, 2200 J)
02 in series (60 Ω)
2.5 (12)
SCA06D14P0T4
RF200 (30 Ω, 200 W, 2200 J)
01
4.0 (10)
SCA06E30P0T4
(*)
RF200 (30 Ω, 200 W, 2200 J)
02 in parallel(15 Ω)
6.0 (8)
(*) Mechanics E contains plastic parts over the DC-, DC+ and BR terminals. It is necessary to break those parts in order to access the terminals.
The RF200 set is mounted on a metallic bracket ready to be installed on the machine or application. This resistor
meets the requirements of most applications. For further details, refer to
item 8.3.3 Braking Resistor RF200 on
page 8-27
.
3.2.3.2.2 Installation of the Braking Resistor
Connect the braking resistor between the power terminals +UD and BR.
Use a twisted cable for the connection. The minimum gauge is informed in
Table 3.2 on page 3-13
. Separate
these cables from the signal and control signal.
If the braking resistor is mounted within the cabinet of the servo drive, consider its energy when dimensioning the
ventilation of the cabinet.
DANGER!
The braking transistor and resistor may suffer damages if the resistor is not properly dimensioned, if the
parameters are not correctly set and/or if the supply voltage exceeds the maximum permitted value.
In order to ensure the protection of the installation in case of a braking circuit failure and prevent the
destruction of the resistor or risk of fire, a thermal relay must be included in series with the resistor
and/or a thermostat in contact with its housing, connected so as to disconnect the input power
supply of the servo drive in case of overheating of the resistor, as shown in
Figure 3.7 on page 3-14
.