XB2-BS8445

1. Overview

The XB2-BS8445 is a complete emergency stop mushroom pushbutton from Telemecanique (Schneider Electric's industrial brand), belonging to the Harmony XB2 series of 22mm panel-mount pilot devices. It features a 40mm red mushroom head with a turn-to-release (twist-to-unlatch) mechanism — the operator presses the head to stop, then rotates it to release the latched-off state. The part number decodes as: XB2 = Harmony 22mm series, BS = complete emergency stop unit (head + contact block integrated), 8 = 40mm mushroom head, 4 = turn-to-release, 45 = 1NC contact configuration. The unit is now discontinued by the manufacturer; the correct modern replacement is the XB4BS8445 (metal body version) or, per Schneider's own FAQ, the modular approach using a ZB4-BS844 head with a ZB4-BZ101 contact block.

2. User Sentiment

No dedicated forum or user review content was found for this specific part. Secondary-market sellers (particularly German dealer maranos_de with 26,000+ positive eBay feedbacks) receive strong buyer reviews: "very friendly and helpful seller," "excellent and detailed communication," "arrived within the stated delivery time," "outstanding packaging and very fast shipping." The part's discontinued status has driven secondary-market availability, with buyers sourcing new-old-stock (NOS) units via eBay, Radwell, EU Automation, and Santa Clara Systems. No complaints about the device's function were found in the snippets reviewed.

3. Real-World Applications

The XB2-BS8445 is used as a machine-frame emergency stop in industrial automation equipment. It appears as OEM part E-011-0025 in Mydata SMT pick-and-place machines (MY9, MY12, MY15, MY19), where it serves as the "red main safety switch button on framework" with turn-to-release (spring-back function). Broadly, the XB2-BS family is deployed across industrial machinery, conveyors, packaging lines, and control panels wherever a compact 22mm e-stop is required in compliance with IEC/EN safety standards.

4. Technical Specifications

• Type: Complete emergency stop mushroom pushbutton (head + 1NC contact block, integrated unit)
• Mounting: 22mm panel hole (Ø 22mm)
• Mushroom head: 40mm diameter, red
• Release mechanism: Turn-to-release (rotate clockwise to unlatch; also described as "Drehentriegelung" in German sources)
• Contact configuration: 1NC (normally closed — opens on press, latches, re-closes on turn-to-release)
• Rated current: 10A
• Rated voltage: 600VAC
• Lifecycle status: DISCONTINUED BY MANUFACTURER
• Correct modern replacement: XB4BS8445 (metal 22mm series); NOTE: Schneider's substitution table erroneously listed ZB4BS8445, which is not a valid part number — corrected to XB4BS8445 in January 2010 database update
• Standards: Harmony XB2 series complies with IEC 60947-5-1 (confirmed via family; positive opening per IEC 60947-5-5 / EN ISO 13850 applicable to the contact block)

5. Ordering & Compatibility

The XB2-BS8445 is widely available through industrial surplus distributors at approximately EUR 56–70 / ~USD 60–75 per unit (NOS new-in-box). Radwell International (US, CA, UK) and EU Automation offer it with 2-year and 12-month warranties respectively. German dealer maranos_de (eBay) and Kempston Controls also stock it. The "844x" suffix family includes XB2BS8442, XB2BS8444, XB2BS8445, XB2BS8446, XB2BS8447 — differing in contact configuration. The XB2BS8445C is a variant with a slightly updated suffix (likely China/C-market designation). For new builds, Schneider recommends XB4BS8445 (metal 40mm turn-release e-stop, 22mm, 1NC) as the drop-in modular replacement.

6. Known Issues

Schneider Electric's official cross-reference database contained a documented error: the substitution table listed ZB4BS8445 as the replacement for XB2BS8445, but ZB4BS8445 is not a valid Schneider part number. The correct replacement is XB4BS8445. This was acknowledged in FAQ FA198526 and the commercial database was corrected in January 2010, though the cross-reference list lagged. Buyers sourcing replacements should verify they are ordering XB4BS8445 (not ZB4BS8445). A significant clone/counterfeit ecosystem exists on Alibaba and Chinese marketplaces — multiple suppliers list "original supply" units; buyers should source from reputable distributors for safety-critical applications.