Bei924-01017-022ARotary Incremental Optical Encoder, 625 PPR, A/B/Z Single-Ended, 7406R Open-Collector Output with Internal Pull-Ups, LED Source, Shaft Seal

Product Description

What this part is

This is a BEI Sensors H29-series rotary incremental optical encoder. A shaft-driven optical disc generates two square-wave channels 90° apart plus a once-per-revolution index pulse, so a controller can count position, work out direction from the channel phasing, and find a repeatable home reference. It is an incremental encoder, not an absolute one and not a resolver: it reports change, so position is only known after homing.

924-01017-022A is BEI’s factory model number for this exact build. H29E-SB-625-ABZ-7406R-LED-S is the same encoder written as its configuration string, and it is the more useful of the two because every field is readable.

Decoding the model string

H29 — the H29 heavy-duty industrial encoder family; the number reflects the housing size class.
E — the housing and mounting configuration within the family.
SB — the shaft configuration and diameter code.
625 — 625 pulses per revolution. This is the field buyers search on and the one that must match, because a controller scaled for one PPR reads every other one as a wrong feed rate or a wrong position.
ABZ — output channels: A and B in quadrature plus the Z index, single-ended. Note what this is not: ABZC in the BEI scheme adds the complementary channels for differential transmission. If your drive or counter card expects differential A/Ā, B/B̄, Z/Z̄, this encoder does not supply them.
7406R — the output driver: 7406 open collector with internal pull-up resistors. BEI sizes those pull-ups at roughly 100 ohms per volt of supply and the driver’s current sink is limited, so this is a modest-drive output, not a differential line driver.
LED — LED light source rather than an incandescent lamp. This matters for service life: the lamp is the wear item on older optical encoders, and an LED build is the long-life option.
S — shaft seal fitted.

What these specs mean in practice

The output type is the compatibility gate, not the pulse count. Open collector with internal pull-ups is happy over a short, clean cabinet run into a counter or PLC high-speed input, and it tolerates a receiver whose logic supply differs from the encoder’s. What it does not do is drive a long cable in an electrically noisy machine: without the common-mode rejection of a differential pair, a 30 m run alongside a motor cable will pick up PWM noise and give you phantom counts — which present as position drift that grows over a shift rather than as an obvious fault. If the run is long or the environment is noisy, a differential (ABZC) line-driver build is the right answer.

625 PPR is an unusual, deliberately chosen count. Encoder counts like 625 exist because the machine’s gearing or lead makes the arithmetic come out in round engineering units — often a metric lead or a specific gear ratio — so substituting a 500 or 1000 PPR encoder is not a neutral swap even where it fits the shaft. And because the Z index fires once per turn, its position relative to your machine’s home switch is what sets repeatable homing: after fitting, re-establish home and verify it, do not assume the new encoder’s index lands where the old one’s did.

The shaft seal makes this build suitable for a machine environment with coolant mist or swarf around the mounting face, which is exactly why it is specified on an industrial H29 rather than a laboratory unit.

Published specifications

Type: rotary incremental optical encoder, shaft driven
Resolution: 625 pulses per revolution
Output channels: A, B in quadrature, plus Z index — single-ended
Output driver: 7406 open collector with internal pull-ups (approximately 100 ohms per volt; limited current sink)
Light source: LED
Shaft seal: fitted
BEI factory model number: 924-01017-022A

Quantity and configuration

Sold as one encoder. No mating cable or connector, no flexible shaft coupling, no mounting flange, adapter plate or tether arm, and no manual are included. Encoder installations are made or broken by the coupling, so plan on the right one: a rigid connection transfers shaft misalignment straight into the bearings and shortens the encoder’s life dramatically.

Installation and setup notes

Use a flexible coupling and align the shafts properly — encoder bearings are small and are not designed to carry side or axial load from a misaligned drive. Do not press, hammer or lever anything onto the shaft; the optical disc sits directly on it and is unforgiving of shock. Wire the encoder’s common back to the receiver’s common at one point only, and run the signal pair as a screened cable with the screen grounded at the receiver end, away from motor power and contactor wiring. Confirm the supply voltage the driver’s pull-ups were sized for before energising. Check channel phasing after fitting: A leading B versus B leading A determines the counting direction, and swapping them is the normal way to correct a motor that counts backwards without rewiring the mechanics. Finally, re-home the axis and verify the index position before returning the machine to production.

Interchange guidance

Searched as 924-01017-022A, 92401017022A, 924 01017 022A, 924-01017, H29E-SB-625-ABZ-7406R-LED-S, H29E-SB-625-ABZ-7406R-LED, H29ESB625ABZ7406RLEDS and BEI H29 625 PPR encoder. Related builds in the same family that differ in one field only: an H29E-SB-625-ABZC-7406R-LED-S adds the complementary channels for differential output, and other PPR counts (500, 1000, 1024, 2048) share the identical housing and shaft — all are carried as cross-references because they capture the same search, but the output type or the pulse count differs, so match your controller’s expectation. BEI’s related H25 and HS25 families use the same configuration-string scheme and the same 7406R and ABZ/ABZC output options, which is why H25 datasheets are the practical reference for decoding an H29 order code. Brand history for search reach: BEI, BEI Sensors, BEI Ideacod, BEI Duncan and now Sensata Technologies, which supports the H-series range today.