Schneider VW3A3407 Encoder Card – Tested ATV61/71 Option

What Is the VW3A3407?

The Schneider VW3A3407 is an encoder interface card for Altivar ATV61 and ATV71 drives. It inserts into the drive’s dedicated option slot and routes encoder feedback signals to the drive for closed-loop vector control with induction motor sensor. It provides push-pull outputs and 24 V DC sensor supply with short-circuit and overload protection.

It is a signal interface option card, not the main control board or the power board. Supplied as Tested replacement stock.

Key Specifications

When This Card Is the Suspect

• EnF（Encoder Fault） — the drive detects an encoder feedback fault. Schneider’s guidance for ATV61/71 lists A/B phase mismatch with motor rotation direction, wiring errors（PNP vs. NPN open-collector）, and EMC interference as primary causes. The card is one link in that signal chain.

• SPF（Speed Feedback Loss） — no encoder feedback signal is received. Check the encoder supply voltage at the card （5 V / 15 V） and cable shielding before concluding the card is faulty.

• AnF（Load Slipping） — encoder speed feedback does not match the reference. This points to the feedback path or encoder mechanical coupling, not necessarily the card itself.

• Encoder configuration locked in stop mode — if the encoder is not fully configured, the drive may remain locked in stop. Verify encoder parameters before replacing hardware

Compatibility Check

Before ordering, confirm:

• Drive series and model — confirm the drive is ATV61 or ATV71（including Q variants）. This card is not for ATV610/630/930 or other platforms.
• Encoder type — VW3A3407 is for 24 V push-pull encoders with A/B and complement signals（input impedance 1000 Ω）. Confirm the encoder output type matches.
• Original card marking — confirm the existing card reads VW3A3407.
• If unsure, send a photo of the original card label and the encoder nameplate before purchase.

FAQ

Does EnF always mean the VW3A3407 card is faulty?

No. EnF indicates an encoder feedback fault. Schneider lists A/B phase mismatch, PNP/NPN wiring errors, and EMC interference as primary causes. Verify encoder wiring, shielding, and parameters before replacing the card.

What encoder type does VW3A3407 support?

It supports 24 V DC push-pull encoders with A/B and complement signals, input impedance 1000 Ω, max cable length 500 m.

Is VW3A3407 compatible with ATV610/630/930?

No. It is designed for ATV61 and ATV71（and Q variants）. Do not order it for the newer ATV600/900 platform without confirming the correct option card for that drive.