The Schneider VW3A3E503 is a water solution multi-pump card designed for Altivar Plus speed drives. It manages sequencing and load sharing across multiple pumps in a water or wastewater installation — think booster sets, lift stations, or circulation loops where the drive needs to coordinate several motors without a separate PLC. Powered from a 24 V DC supply (19...30 V limits), it draws 80 mA unloaded and up to 2 A maximum when driving all outputs. The card provides 10 logic inputs (LI51...LI60) compatible with level 1 PLCs at 24 V DC, plus 6 logic outputs (LO51...LO56) rated 200 mA each at 24 V DC. Two analog inputs (AI51, AI52) accept 0...20 mA with 10-bit resolution and 250 Ω impedance; two analog outputs (AO51, AO52) also handle 0...20 mA at 500 Ω impedance. The 9-way male SUB-D connector provides the drive interface, while field wiring lands on 1.5 mm² terminals at 0.25 N·m.
Battery-backed memory and commissioning
An onboard lithium battery provides 8 years of backup life, retaining pump parameters and fault logs through power loss. That matters for a multi-pump controller: if the panel loses mains, the card remembers the lead-pump rotation schedule and duty-cycle counters without a re-commissioning visit. The card mounts inside the Altivar Plus drive enclosure. Terminal blocks accept 1.5 mm² / AWG 16 wire. The 9-way SUB-D connection to the drive is keyed.