Schneider Electric · Harmony XB4 Serie

ZB4-BS844

Activo
UL CSA CE IEC 60947-5-5

Harmony XB4 Red Mushroom Emergency Stop (Push-Pull)

Número de pieza: ZB4 - B - S - 844
Schneider Electric Harmony XB4 Serie Introduced circa 2003
Schneider Electric ZB4-BS844 — Harmony XB4 Red Mushroom Emergency Stop (Push-Pull)

Red 40mm mushroom head emergency stop push button, push-pull reset, for Schneider Harmony XB4 series. 22mm cutout, IP66.

Aplicaciones comunes

Emergency stop button found on CNC machines, hydraulic presses, industrial robots, and food processing lines. The 40mm mushroom head meets EN/ISO 13850 requirements — large enough to hit with a palm or forearm in a panic. Twist-to-release prevents accidental restart after an emergency — the operator must deliberately acknowledge the event before the machine can run again. Required by OSHA and EU Machinery Directive on any equipment with moving parts that could injure an operator.

Especificaciones

Actuator Type
Mushroom Head
Certifications
UL, CSA, CE, IEC 60947-5-5
Color
Red
Contact Configuration
1NC (with ZB4-BZ102)
Cutout Diameter
22mm
Head diameter
40mm
IP Rating
IP66
Material
Metal
Mounting Type
Panel
Reset type
Push-Pull

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También necesitará

Este es un componente modular. Para un ensamblaje completo, también puede necesitar:

Referencia rápida de instalación

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.

Dimensiones

Front 22mm cutout 40mm head Side panel terminals

Diagrama de cableado

L T 21 22 NC (closed) opens on press

Solución de problemas

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.

Especificaciones rápidas

Actuator Type
Mushroom Head
Certifications
UL, CSA, CE, IEC 60947-5-5
Color
Red
Contact Configuration
1NC (with ZB4-BZ102)
Cutout Diameter
22mm

Lo que dicen los usuarios

+

“Always use NC contacts, always wire through a safety relay, always test monthly. The Schneider ZB4-BS844 twist-release is my go-to — the trigger guard prevents accidental activation. Never wire an e-stop directly to a contactor.”

Reddit r/PLC by safety_plc_guy 45 votos positivos Ver hilo →

Fuentes de datos

Especificaciones y datos de producto obtenidos de las siguientes referencias.

ZB4BS844 Schneider Product Page

https://www.se.com/us/en/product/ZB4BS844/

Consultado el March 30, 2026

Fuente