Schneider Electric · Harmony XB5 Series

XB5-AS8445

Active
UL CSA CE

22mm E-Stop Twist Release Plastic XB5

Part number: A - S - 844
Schneider Electric Harmony XB5 Series Introduced circa 2003

Schneider Harmony XB5 plastic emergency stop.

Common Applications

Budget e-stop with plastic bezel. Same safety function as metal XB4-BS844. Use on indoor panels where corrosion is not a concern. Saves 30-40% per unit on large panel builds.

Specifications

Actuator Function
Twist-release
Actuator Type
Mushroom 40mm
Certifications
UL, CSA, CE
Color
Red
Contact Configuration
1NC
Cutout Diameter
22mm
IP Rating
IP66
Material
Plastic

Installation Quick Reference

Panel cutout: 22mm. Mount with the yellow backing plate visible (required by EN/ISO 13850).

Wiring: Wire NC contacts in series with the safety relay input channels. Use dual-channel wiring for SIL 3 / PLe applications. Never wire directly to a motor contactor.

Testing: Press the e-stop and verify the machine stops within the required time. Test the reset mechanism. Repeat monthly per EN/ISO 13850.

Dimensions

Front 22mm cutout 40mm head Side panel terminals

Wiring Diagram

L T 21 22 NC (closed) opens on press

Troubleshooting

E-stop won't reset (twist/pull doesn't release)

Check for debris in the mechanism. For twist-release: turn clockwise 45-90 degrees. For push-pull: pull straight out firmly. If the mechanism is stuck, the internal latch may be damaged — replace the entire head assembly.

Machine doesn't stop when e-stop is pressed

Critical safety issue. Immediately lock out the machine. Check wiring — NC contacts must be in series with the safety relay. Verify the safety relay is functioning. A broken wire in an NC circuit should cause a stop, so check for a wiring bypass.

Safety relay faults after e-stop reset

The safety relay detects a cross-fault between the two monitoring channels. Check that both NC contacts on the e-stop are switching simultaneously. One contact may be welded closed — replace the contact block.

Where to Buy

Price range

$29.41 — $48.46

across 2 distributors

Quick Specs

Actuator Function
Twist-release
Actuator Type
Mushroom 40mm
Certifications
UL, CSA, CE
Color
Red
Contact Configuration
1NC

What People Are Saying

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“Budget e-stop with plastic bezel. Same safety function as metal XB4-BS844. Use on indoor panels where corrosion is not a concern. Saves 30-40% per unit on large panel builds.”

Reddit r/PLC 21 upvotes View thread →