Industrial control systems rely on components that are both durable and precise. Among these, the Schneider Electric Harmony XB4 Contact Block stands out as a reliable solution for operators, engineers, and maintenance teams worldwide. Designed with robust materials, superior contact reliability, and compliance with global standards, the Harmony XB4 series has become a trusted component for control circuits and panel assemblies.
In this comprehensive guide, we will explore the Schneider Electric Harmony XB4 Contact Block (ZB4BZ105) in detail—covering its features, specifications, certifications, compatible accessories, and installation insights. Whether you’re designing a control panel, replacing a worn-out block, or optimizing a machine interface, this guide will help you understand why the ZB4BZ105 remains one of the most preferred contact blocks in industrial automation.
Understanding the Schneider Electric Harmony XB4 Contact Block
The Schneider Electric Harmony XB4 Contact Block (model ZB4BZ105) is a complete 22 mm contact block assembly featuring a metal body and fixing collar. It integrates both 1 Normally Open (NO) and 1 Normally Closed (NC) contact, allowing flexible control logic configurations for pushbuttons or selector switches. Built for the Harmony XB4 series, this contact block ensures secure panel mounting and dependable performance in demanding industrial environments.
The ZB4BZ105 uses screw-clamp terminals that support up to two 1.5 mm² ferruled conductors. This design provides vibration resistance and ensures stable connections compliant with EN 60947-1 standards. The metal fixing collar adds extra rigidity, preventing loosening or displacement under mechanical stress.
Technical Specifications of the Harmony XB4 Contact Block
As part of the Harmony XB4 family, the Schneider Electric ZB4BZ105 demonstrates robust electrical and mechanical performance suitable for diverse applications.
Electrical Ratings
- Contact configuration: 1 NO + 1 NC (slow-break operation)
- Thermal current (Ith): 10 A (free air)
- Rated insulation voltage (Ui): 600 V
- Impulse withstand voltage (Uimp): 6 kV
- Switching capacity:
- AC-15: 3 A @ 240 VAC (A600), 6 A @ 120 VAC (A600)
- DC-13: 0.1 A @ 600 V, 0.27 A @ 250 V (Q600)
- Recommended short-circuit protection: 10 A gG fuse
Mechanical Characteristics
- Mounting type: Panel-mounted, 22 mm cut-out
- Dimensions: Approx. 30 x 47 x 37 mm (W x H x D)
- Weight: 0.062 kg
- Operating travel: 1.5 mm (NC), 2.6 mm (NO), total travel 4.3 mm
- Mechanical life: 5 million operations
- Operating temperature: -40°C to +70°C
Terminal Design
The screw-clamp terminals are compatible with cross, flat, and Pozidriv drivers (No. 1 Philips or slotted 4 mm/5.5 mm). The tightening torque ranges from 0.8 to 1.2 N·m, ensuring secure wire fastening. The contacts are made from silver-nickel alloy (Ag/Ni), known for excellent conductivity and arc resistance.
Durability
The Schneider Electric Harmony XB4 Contact Block is designed to withstand extreme environments. Its metal body provides superior resistance to vibration, mechanical impact, and corrosion, making it ideal for long-term industrial operation.
Datasheet Highlights: Why the Harmony XB4 Stands Out
The official Schneider Electric datasheet highlights the ZB4BZ105’s key features:
- Quick assembly and disassembly: The modular design simplifies installation and maintenance.
- Rugged construction: Metal body and fixing collar enhance durability.
- Compatibility: Works seamlessly with all Harmony XB4 operator heads.
Schneider Electric also provides variations of this block, such as:
- ZB4BZ1053: With plug-in connectors
- ZB4BZ1055: With spring-clamp terminals
These alternatives cater to installers who prefer different wiring techniques, ensuring flexibility across industrial applications.
Compliance and Certifications
The Schneider Electric Harmony XB4 Contact Block (ZB4BZ105) complies with multiple international standards for industrial control components. These include:
- IEC/EN 60947-1 and IEC/EN 60947-5-1 (control circuit devices)
- JIS C8201-5-1 (Japan)
- UL 508 and CSA C22.2 No.14 (North America)
Additionally, the block carries certifications from:
- DNV (Det Norske Veritas)
- Lloyd’s Register of Shipping (LROS)
- Bureau Veritas (BV)
- GL (Germanischer Lloyd)
Its IP20 protection rating safeguards users from direct contact with live parts, while pairing it with sealed operator heads can enhance front-panel protection up to IP69K, depending on configuration.
Alternative Models in the Harmony XB4 Series
The Harmony XB4 line offers several configurations to suit various applications:
- ZB4BZ106 – 1NO + 1NC (overlapping contact type)
- ZB4BZ107 – 2NO contact configuration
- ZB4BZ141 – 1NO + 2NC for complex interlocks
These variants provide design flexibility across different control schemes. Moreover, Schneider offers gold-plated contact versions for low-current or electronic circuits, ensuring reliable switching in sensitive control systems.
Compatible Accessories for the ZB4BZ105 Contact Block
Enhance your Harmony XB4 Contact Block installation with compatible accessories:
- Mounting Collar: Secures the contact block and operator head to the panel.
- Vibration Clip (ZBZ007): Provides additional retention under heavy vibration.
- Pushbutton Boots and Covers: IP69K-rated dome covers protect against dust and washdowns.
- Indicator Modules: Combine illumination and switching functionality.
- Wire Ferrules and Standard Tools: Simplify terminal connection.
These accessories make the Schneider Electric Harmony XB4 Contact Block a customizable, long-lasting choice for industrial control panels.
Mounting and Installation Guide
Mounting the Schneider Electric ZB4BZ105 Contact Block is straightforward and follows Schneider’s industry-standard procedure:
- Insert the Operator Head into a 22 mm panel hole from the front.
- Attach the Metal Fixing Collar from the rear and lock it until it clicks.
- Tighten the Ground Screw to secure the assembly.
- Snap the ZB4BZ105 Block onto the rear of the collar by aligning and engaging the hooks.
- Connect the Wires to the terminals, tightening to 0.8–1.2 N·m.
When correctly mounted, this creates a highly durable pushbutton assembly capable of withstanding vibration, temperature fluctuations, and repetitive use.
Typical Applications of the Harmony XB4 Contact Block
The Schneider Electric Harmony XB4 Contact Block finds widespread use across industrial sectors, including:
- Manufacturing and Process Plants: For start/stop stations and operator interfaces.
- Automotive Industry: In control panels and assembly-line equipment.
- Marine Applications: Certified for shipboard use by DNV and Lloyd’s.
- Food and Beverage: With sealed boots, it fits washdown-rated installations.
- Automation Systems: Provides reliable interface between human operators and PLCs.
Thanks to its high electrical endurance, the ZB4BZ105 effectively manages both signal and low-power control circuits, making it a versatile component for industrial automation and control reliability.
Why Choose the Schneider Electric Harmony XB4 Contact Block
The Harmony XB4 Contact Block is a benchmark in Schneider’s line of industrial control components. Here are the key reasons professionals prefer it:
- Durability: Metal body resists wear, shock, and corrosion.
- Flexibility: Works with all XB4 operator heads.
- Ease of Maintenance: Snap-on mechanism simplifies replacement.
- Certified Reliability: Meets global standards for industrial safety and performance.
- Long Mechanical Life: Up to 5 million cycles for dependable long-term use.
Related Product Collections You Might Like
Explore more from Industrial Electrical Warehouse to complement your control system setup:
Explore a full range of contact blocks from leading brands including Schneider Electric, built for durability and precision control in industrial environments.
Push Buttons & Switches Collection →
Find operator heads, selector switches, and complete assemblies to pair with your Harmony XB4 contact blocks for superior performance.
Motor Control Equipment Collection →
Equip your panel with contactors, overload relays, and starters to achieve reliable and efficient motor control solutions.
Conclusion: Building Reliable Control Systems with Harmony XB4
The Schneider Electric Harmony XB4 Contact Block (ZB4BZ105) offers more than just electrical connectivity—it delivers confidence in every operation. Its modularity, rugged construction, and compliance with international standards make it a cornerstone of reliable control systems across industries.
For engineers and panel builders seeking a dependable and globally certified component, the Harmony XB4 series represents a sound investment. Explore the ZB4BZ105 Contact Block and related Harmony products to enhance the safety, efficiency, and reliability of your control circuits.
👉 Discover the complete range of Harmony XB4 components at Industrial Electrical Warehouse and choose the model that fits your next automation project.
