Command Fuses; Dynamic Braking - WEG CFW-11 User Manual

Installation and Connection

3.2.3.1.2 Command Fuses

Besides the RFI filter capacitors and the MOV's, the PRT1 board also has 3 fuses for protecting the inverter
command circuit.
The PRT1 board location is presented in the figure 3.13 (a).
The location of the PRT1 fuses is presented in the figure 3.13 (b).
See below the specification of the used command fuses:
Slow blow fuse 0.5 A / 600 V;
Manufacturer: Cooper Bussmann;
Part number: FNQ-R-1/2;
WEG part number: 10411493.
Consider the following items for the use of protection devices on the supply side of the inverter such as residual
current devices or isolation monitors:
- The detection of a phase-to-ground short-circuit or an insulation fault shall be processed by the user, i.e., the
user shall decide whether to indicate the fault and/or block the inverter operation.
3
- Contact the RCD manufacturer for selecting the most appropriate device to be used with inverters in order to
avoid nuisance tripping due to the high frequency leakage currents that flow through the leakage capacitances
of the inverter, cable, and motor system to the ground.

3.2.3.2 Dynamic Braking

ATTENTION!
For the CFW-11 frame size E models, only those with the DB option (CFW11XXXXTXODB) have the
braking IGBT incorporated to the product.
The braking torque that can be obtained from the frequency inverter without braking resistors varies from 10 %
to 35 % of the motor rated torque.
Braking resistors shall be used to obtain higher braking torques. In this case, the energy regenerated in excess
is dissipated in a resistor mounted externally to the inverter.
This type of braking is used in cases where short deceleration times are desired or when high inertia loads are
driven.
For the vector control mode, there is the possibility of using the "Optimal Braking", eliminating in many cases
the need of dynamic braking use.
NOTE!
Set P0151 and P0185 to their maximum values (400 V or 800 V) when using dynamic braking.
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