Danfoss vlt FC 102 - Discharge Resistors

5.8.3 Discharge Resistors
There are common positive and negative DC terminals on each drive module. If a shorter time to achieve the reduced run
functionality is wanted, connect the external discharge resistor for quicker discharge of DC-link voltage. It is possible to
connect a discharge resistor in an additional cabinet, through a contactor. This discharge contactor should have an interlock
with the mains contactor/disconnector’s auxiliary NC contacts to avoid a discharge when the drive system is powered.
Illustration 8.7 shows a 4-drive system with discharge resistor connections.
Base the selection of a discharge resistor on the energy and power levels given in Table 5.12 for
dierent power sizes, on
both 12-pulse and 6-pulse systems.
FC 102
FC 202
N500 N560 N630 N710 N800 N1M0
FC 302 N450 N500 N560 N630 N710 N800
Drive modules required
(HO rating)
2xN250 4xN160 4xN200 4xN200 4xN250 4xN250
Resistance required to reduce DC
voltage below 50 V within 300 s
(5 minutes), Ω
3036 2277 1822 1822 1518 1518
Power rating of resistor (W) 182 242 303 303 363 363
Energy dissipated by resistor (J) 7773 10365 12956 12956 15547 15547
Table 5.12 Discharge Resistors Recommended for Drive Systems with 380–480 V AC Mains Supply
FC 102
FC 202
N630 N710 N800 N900 N1M0 N1M2
FC 302 N560 N630 N710 N800 N900 N1M0
Drive modules required
(HO rating)
2xN315 4xN200 4xN250 4xN250 4xN315 4xN315
Resistance required to reduce DC
voltage below 50 V within 300 s
(5 minures), Ω
4571 3047 2285 2285 2285 2285
Power rating of resistor (W) 230 345 459 459 459 459
Energy dissipated by resistor (J) 8819 13229 17638 17638 17638 17638
Table 5.13 Discharge Resistors Recommended for Drive Systems with 525–690 V AC Mains Supply
NOTICE
Danfoss is not responsible for any failure or malfunction of the resistor, or for any misconnections made by the installer.
NOTICE
The wire used with the brake resistor should be double-insulated or have reinforced insulation.
Electrical Installation
VLT
®
Parallel Drive Modules
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