Braking unit for 400 V class drives — what the ratings mean
The VW3A7209 is a network braking unit rated 160 kW peak braking power and 86 kW continuous (permanent) braking power at 400 V supply — the gap between the two numbers tells you the duty cycle the resistor network can sustain before thermal recovery is needed. It operates on 380–415 V supplies and draws a recommended 350 A fuse at 660 V, which sets the upstream protection size for the branch circuit supplying the braking module. Overload protection is set at 1.2× the maximum current — the unit will hold that margin before tripping, so the drive's braking chopper threshold should be coordinated below this ceiling.
Panel fit and environmental limits
The enclosure measures 837 mm high × 380 mm wide × 395 mm deep at IP20 — this is a floor-standing or large panel-mount footprint, not a DIN-rail module; plan for bottom cable entry and top ventilation clearance. Rated efficiency is 97 % with a power factor of 1 (cos phi = 1), meaning the braking unit draws near-unity current from the DC bus with minimal reactive component. Operating altitude is 1000–4000 m with a 5 % current derating per additional 1000 m above sea level — installations above 1000 m must reduce the braking current proportionally to stay within the thermal envelope. Storage temperature range is -25 to 55 °C; the unit can sit in an unheated warehouse or shipping container within that band without damage.
Obsolete — sourcing through independent channels
Available through independent surplus and broker channels; quantities are lot-specific and confirmed at RFQ. No pin-compatible or form-fit-function replacement is documented by Schneider, so a substitution requires a full braking-unit selection review against the drive's DC bus voltage and braking duty cycle.