B&R 8YS-K0055R0.005-0 Servo Motor

Product Introduction & Engineering Value

The B&R 8YS-K0055R0.005-0 is a legacy B&R servo motor intended for precision machine motion. The model is associated with the B&R 8YS product family, while available industrial listings identify 4.04 A current, 3.77 Nm torque, 640 VDC, and IP65 protection.

This is a part where exact identification matters. The K0055R0.005-0 designation should be matched character-for-character before ordering. Do not substitute a superficially similar B&R motor based only on flange dimensions or nominal power. Feedback, winding data, drive compatibility, shaft configuration, and machine parameters all need to agree.

Technical Specifications

The 6.1 kg / 13.45 lb weight is reported independently by Radwell and Electrical.com.

A note on contradictory specifications

Some suppliers report 6,000 RPM for the exact 8YS-K0055R0.005-0, while another listing claims approximately 3,000 RPM and still another source publishes substantially different motor data.

That discrepancy is significant. I would not publish a definitive rated speed, rated power, encoder resolution, or winding specification for this part without checking the physical nameplate or an original B&R datasheet. Doing so creates a real procurement risk.

Field Application & the “Trench” Experience

A typical legacy-machine replacement starts with a deceptively simple failure: a servo axis stops during production, the motor is suspected, and maintenance finds that the original B&R part is no longer available through normal production channels.

The replacement problem is then less about finding “an 8YS motor” and more about finding the exact 8YS-K0055R0.005-0 configuration.

For example, imagine a high-speed inspection machine where the motor drives a precision indexing mechanism. The replacement motor arrives, physically fits, and passes a basic insulation test. The engineer installs it, but the axis immediately generates a feedback or motor-identification fault. The problem is not necessarily the motor itself. A different feedback configuration, incorrect motor data, or incompatible drive parameters can produce exactly this type of commissioning failure.

That is why this part should be purchased using the complete part number plus photographs of the actual nameplate.

Specific application scenarios

• High-speed inspection indexing mechanisms requiring repeatable servo positioning.
• Electronic assembly machinery with legacy B&R motion axes.
• Precision material-handling axes where replacement of the existing servo motor is preferable to redesigning the complete control system.
• Machine-tool auxiliary positioning where the original B&R servo architecture remains in operation.

8YS-K0055R0.005-0

8YS-K0055R0.005-0

Transparency SOP: QA & Testing

For New Surplus inventory, a reasonable receiving procedure is:

Part identification → physical inspection → electrical inspection → feedback verification → controlled functional test.

The first step is particularly important. Verify that the physical label reads 8YS-K0055R0.005-0 rather than relying on a warehouse label or reseller description.

For a motor advertised as unused, inspect:

• Housing and mounting surfaces
• Shaft and keyway
• Connectors
• Seals and bearings
• Nameplate
• Signs of corrosion or moisture exposure
• Original packaging and storage condition

For refurbished equipment, require evidence of electrical and mechanical testing. One supplier currently advertises refurbished units with insulation testing up to 1,000 V, rotor-balance testing, electrical measurements, new bearings, and a 24-month supplier warranty.

That is supplier warranty coverage, not automatically B&R factory warranty.

Radwell likewise states that factory warranty may not apply and separately offers its own two-year warranty.

The Veteran’s Tech Trap Guide

⚠️ Trap #1 — Treating the online specification as authoritative

This model has unusually inconsistent secondary-market specifications. One source identifies 4.04 A / 3.77 Nm / 640 VDC / IP65, while another publishes an entirely different motor configuration.

PRO TIP: Request a high-resolution photograph of the actual B&R nameplate before placing a purchase order.

⚠️ Trap #2 — Assuming every 8YS motor is interchangeable

It isn’t. B&R model suffixes encode configuration details. A motor that looks mechanically similar can still have different electrical or feedback characteristics.

Match the entire part number, not just 8YS.

⚠️ Trap #3 — Confusing a supplier warranty with OEM warranty

Several aftermarket suppliers sell this discontinued motor with their own warranties. That can be useful, but it does not mean the product carries current B&R factory warranty coverage. Radwell explicitly states that factory warranty may not apply.

⚠️ Trap #4 — Buying from a representative stock photograph

At least one listing explicitly states that the displayed image is representative and that the actual product may vary.

For a discontinued servo motor, the actual unit’s nameplate, connector arrangement, shaft, and physical condition matter more than a catalog photograph.

Dynamic FAQ

What is the B&R 8YS-K0055R0.005-0?

It is a B&R 8YS-series servo motor. Industrial parts databases classify the exact part number as a servo motor and report 4.04 A, 3.77 Nm, 640 VDC, and IP65.

Is the 8YS-K0055R0.005-0 discontinued?

Yes. Multiple aftermarket sources identify the exact part number as discontinued by the manufacturer.

What is the motor’s rated speed?

This is one specification I would not state as definitive without verifying the physical unit. Online sources conflict: one lists 6,000 RPM, while another reports approximately 3,000 RPM.

For an engineering replacement, use the original nameplate and B&R documentation.

Is the motor IP65 rated?

Yes. The exact model is listed as IP65 by multiple industrial automation suppliers.

Can I buy it as New Surplus?

Yes. Current secondary-market listings show the exact part number in unused original packaging, unused repackaged condition, and refurbished condition.

How should I verify New Surplus authenticity?

Ask for photographs of the actual motor, nameplate, connectors, shaft, and packaging. Confirm that the part number is exactly 8YS-K0055R0.005-0, then obtain the supplier’s written condition statement and warranty terms. For a discontinued B&R component, those checks are worth doing before issuing the PO.