Electrical Installation; Pre-Charge - WEG CFW-11W G2 RB Series User Manual

Installation and Connection

3.4 ELECTRICAL INSTALLATION

DANGER!
The following information is intended to be a guide for proper installation. Comply with applicable
local regulations for electrical installations.
DANGER!
Make sure the power supply is disconnected before starting the connections.
3
ATTENTION!
The CFW-11M G2 RB and CFW-11W G2 RB can be connected to circuits with short-circuit capacity
of up to 100000 symmetric Arms (maximum 480 V/690 V).
ATTENTION!
The short-circuit protection of the converter does not provide short-circuit protection for the feeder
circuit. The short-circuit protection of the feeder circuit must be provided in accordance with the
applicable local regulations.

3.4.1 Pre-Charge

The resistors of the pre-charge circuit must be sized according to the following criteria:
Maximum voltage.
„
Maximum energy.
„
Power overload capacity of the resistors during the pre-charge period (energy dissipation capacity).
„
Peak current during the pre-charge (A)
Energy stored in the capacitor bank (J)
Pre-charge duration
(1) This calculation considers the use of the same number of power units in the regenerative frequency
converter and in the inverter connected to the motor. When the CFW11M RB G2 or CFW11W RB G2 feeds
several other inverters, you must consult WEG for the correct sizing of the pre-charge resistor.
Being R the ohmic value of the resistor used on each phase and N the number of regenerative power units.
Table 3.15 on page 3-22
3-22 | CFW-11MW G2 RB
Table 3.14: Sizing of the pre-charge
(1)
(1)
contains the maximum ohmic value that can be applied to the pre-charge resistors.
Table 3.15: Maximum pre-charge resistor value for the CFW11M G2 RB
Power Supply
Nº. of UP11s
380-480 V
1 5.0 Ω
2 2.5 Ω
3 1.5 Ω
4 1.2 Ω
5 1.2 Ω
0.82 x (V
UP11-01 G2 N.0.012.V
UP11-02 G2 N.0.024.V
UP11W-01 G2 N.0.014.V
UP11-01 G2 0.1.N.R
UP11-02 G2 0.2.N.R
UP11W-01 G2 0.11.N.R
Power Supply Power Supply
500-600 V 660-690 V
11.0 Ω 7.5 Ω
3.8 Ω 5.0 Ω
2.5 Ω 3.5 Ω
2.0 Ω 2.5 Ω
1.8 Ω 2.0 Ω
/R)
line
2
line
2
line
2
line