Schneider Electric ZB4BS844 Harmony XB4 Emergency Stop Head Red Mushroom 40 mm Emergency Stop Push Button

The Schneider Electric ZB4BS844 is a Harmony XB4 head for an emergency-switching-off pushbutton, built around a red, 40 mm, unmarked mushroom actuator in chromium-plated metal. It trips on a trigger action with mechanical latching and releases only by turning the mushroom, mounting in a 22.5 mm panel cutout ahead of a compatible XB4 contact body.

Technical Specifications

Certifications & Standards

• DNV
• UL Listed
• LROS
• BV
• CSA
• UL 508
• IEC 60947-5-5
• CSA C22.2 No 14
• IEC 60947-5-4
• JIS C8201-5-1
• IEC 60947-1
• IEC 60947-5-1
• IEC 60204-1
• IEC 60364-5-53
• GB 14048.5
• ISO 13850
• JIS C8201-1

Selection Notes

Mechanical latching on trigger action means the mushroom stays pressed in the moment it is struck, and it cannot be restarted until an operator deliberately turns it to release - the turn-to-release reset is the standard interlock against an accidental restart on a machine that was just stopped for safety. The 40 mm mushroom diameter and IP69K rating make this head suitable for a primary e-stop station on a washdown line; choose the illuminated ZB4BW643 variant instead when the station also needs a lit status indicator.