Simplifying Panel Design and Safety with TeSys VLS Disconnect Switches

Most industrial infrastructure requires disconnect switches to isolate electrical circuits safely. Whether used for maintenance, emergency shutdowns, or regulatory compliance, these switches play a key role in ensuring system safety and serviceability. Schneider Electric's TeSys VLS Disconnect Switches meet these requirements with compact, modular designs rated from 25 A to 125 A for UL 508 and UL 98 applications. Typical use cases include motor isolation, feeder disconnection, and protection of the electrical panel.

Part of the broader TeSys product line for motor control and protection, the VLS series supports industrial and commercial systems across various applications, including material handling, HVAC, pumping, solar energy, and mining. Available in both DIN-rail and door-mounted formats, these switches can be configured with accessories such as auxiliary contact blocks (as shown in Figure 1), padlockable handles, fourth poles, and terminal shrouds to address specific safety and regulatory requirements.

Figure 1. The Schneider Electric TeSys VLS auxiliary contact block provides status indication or interface with safety and control systems. (Image source: Schneider Electric)

Certified to UL, CSA, and IEC standards, the TeSys VLS series offers consistent mounting dimensions and scalable options that simplify panel design and reduce component variability.

This article reviews the practical differences between UL 508 and UL 98 standards, highlights common use cases across various applications, including HVAC, material handling, solar, and energy, and outlines how the TeSys VLS modular architecture facilitates flexible mounting and configuration. It also explores how accessories like padlockable handles, auxiliary contacts, and interlocks contribute to safety functionality and compliance with lockout/tagout protocols. Lastly, it explains how standardized components and consistent form factors help simplify enclosure design and reduce inventory complexity for panel builders and system integrators.

Disconnect switches and standards: UL 508 vs. UL 98

Industrial disconnect switches must comply with standards that reflect their intended function within an electrical system. UL 508 covers motor controllers for load-side applications, while UL 98 defines general-use switches for feeder disconnection. These standards differ in application scope, performance requirements, and fault-handling capabilities.

UL 508 applies to manual motor controllers used for load-side disconnection, typically isolating motors or equipment within localized sections of a panel. These switches are commonly deployed for individual loads — such as fans or pumps — where disconnection under full fault conditions isn't required. UL 508 models feature a 5 kA short-circuit rating and compact 36 mm form factors optimized for space-constrained applications.

UL 98 applies to general-use switches designed to disconnect entire feeders or serve as the main disconnecting means for a panel. These models must meet stricter performance thresholds, including 10 kA fault current ratings and higher endurance under load. UL 98 switches typically feature larger 70 mm form factors to support higher current-carrying capacity and fault interruption capability.

UL 508 and UL 98: TeSys VLS technical specifications

Schneider Electric’s TeSys VLS line includes both UL 508 and UL 98 certified options, facilitating design flexibility while maintaining consistent mechanical footprints. UL 508 models, such as the TeSys VLS 25A disconnect switch (shown in Figure 2), 32A model, and 40A variant, support compact panel layouts and branch circuit protection.

Figure 2. The 25 A, 3-pole Schneider Electric TeSys VLS3P025R1 disconnect switch is UL 508-certified and designed for compact load-side disconnection in panel layouts. (Image source: Schneider Electric)

Higher-capacity models, including the TeSys VLS 63A UL 98 switch and 125A model, carry UL 98 certification for feeder-level disconnects and main isolation in power distribution systems. A detailed comparison of key specifications, including current range, short-circuit rating and terminal capacity, is highlighted in Table 1 below.

Table 1: Comparison of UL 508 and UL 98 TeSys VLS disconnect switch specifications.

A stand-out feature of the TeSys VLS line is the 63 A crossover point, where both UL 508 and UL 98 certification options are available. System designers can choose between the compact UL 508 switch and the full-size UL 98 switch based on available panel space, required fault interruption capacity, and applicable standards. This design flexibility allows compliance with both U.S. and international regulations, such as NEC 430.102 and IEC 60947-3.

Industrial and commercial applications

The TeSys VLS disconnect switch lineup supports a wide range of industrial and commercial applications, from localized equipment isolation to feeder-level disconnection. The VLS series offers flexible form factors, certification options, and operating ranges that meet the requirements of:

• Material Handling: Dual-certification 63A options, such as the compact TeSys UL 508 VLS model for space-constrained installations and UL 98-rated TeSys VLS switch for main disconnects, allow system designers to optimize conveyor motor control panels for both individual drive isolation and main power distribution.
• HVAC Systems: As shown in Figure 3, larger UL 98-rated models such as the TeSys VLS 125A disconnect switch support main panel disconnection for rooftop units or feeder-level isolation in commercial buildings, where higher interrupt ratings and environmental durability are required.

Figure 3. Schneider Electric TeSys VLS3P125D2 body switch, a 125 A, 3-pole UL 98-certified disconnect rated for feeder isolation and main panel disconnection. (Image source: Schneider Electric)

• Pumping Applications: Mid-range models, such as the TeSys VLS 63A UL 98 switch, offer reliable isolation for centrifugal pumps, booster stations, and water treatment systems. UL 98 certification provides adequate fault protection for direct-on-line motor starting, while padlockable handles support maintenance lockout protocols in municipal facilities.
• Solar Installations: Compact UL 508-rated switches such as the TeSys VLS 40A disconnect switch isolate individual 30 kW inverters or DC-AC converters, enabling NEC 690.15 rapid shutdown functionality in tight combiner boxes and inverter enclosures.
• Mining Applications: Heavy-duty UL 98 models, such as the TeSys VLS 125A disconnect switch, perform reliably in harsh conditions across mineral processing, conveyor systems, and ventilation equipment. The -25°C to +55°C operating range and robust terminal design support reliable operation in underground and surface installations where accessibility and isolation are critical.

Modular architecture and efficient panel integration

TeSys VLS disconnect switches feature a modular architecture that simplifies panel design, assembly, and maintenance. Available in both DIN-rail and door-mounted formats, the switches support a wide range of enclosure configurations through:

• Mechanical Consistency: UL 508 models (25 A to 63 A) maintain a uniform width of 36 mm, while UL 98 models (63 A to 125 A) adopt a standardized width of 70 mm. This consistency across current ratings allows the reuse of mounting patterns and enclosure layouts, minimizing the need for custom mechanical design across multiple applications.
• Accessory and Inventory Simplification: Common accessory interfaces reduce BOM complexity and streamline inventory. The TeSys VLS padlockable handle fits all current ratings, while auxiliary contact blocks and terminal configurations remain consistent within each switch size class. Items such as fourth poles, TeSys VLS auxiliary contacts, and terminal shrouds can be installed without modification. TeSys VLS mechanical interlocks support multiple switch combinations using shared mounting interfaces.
• Flexible Mounting and Enclosure Design: Door-mounted versions include shaft extensions that enable direct handle operation on the enclosure face, supporting ergonomic and code-compliant access for shutdown and maintenance. This design approach allows panel builders and OEMs to reduce enclosure depth, unify drilling templates, and accelerate layout iteration, which is crucial in high-mix, low-volume production environments.

By using a single switch family across current ratings and certification classes, engineering teams can streamline product development, while production teams benefit from simplified assembly and reduced variation across power classes and panel types.

Safety, lockout/tagout, and configurable accessory options

Safety and compliance are key considerations for any disconnect switch, especially in systems that require frequent manual access, maintenance, or shutdown. The TeSys VLS series addresses these demands with modular accessories that support personnel protection, standards compliance, and integration into broader safety architectures. These include:

• Padlockable Handles: As shown in Figure 4, the TeSys VLS padlockable handle features a compact 48 × 48 mm form factor with a single-hole mount and IP65 rating, enabling secure front-panel installation in constrained spaces. Red and yellow color coding supports ISO 13850 emergency stop conventions, while integrated padlock features facilitate reliable lockout/tagout (LOTO) procedures.

Figure 4. Schneider Electric TeSys VLSH4S5R rotary handle with IP65 rating and integrated padlock support for front-panel safety access. (Image source: Schneider Electric)

• Status and Control Integration: The TeSys VLS auxiliary contact block offers 1NO+1NC contacts rated for 690 V and 10 A, enabling real-time status indication or integration with PLCs and safety relays. Optional early-break variants support sequencing in safety-critical systems and improved equipment protection.
• Mechanical Interlocks: The TeSys VLS mechanical interlock prevents simultaneous switch operation, facilitating sequential isolation routines in accordance with NFPA 79 and IEC 60204-1. These accessories are compatible with switches rated from 16 A to 40 A and support both changeover and coordinated control.

All TeSys VLS components operate reliably from -25°C to +55°C (per IEC 60947-3), with storage ratings to -40°C, 690 V_AC operation throughout global markets, and installation altitudes up to 3,000 m. Shared interface dimensions and mounting standards across the lineup simplify documentation, streamline field maintenance, and facilitate integration into safety-compliant system designs.

Summary

Schneider Electric’s TeSys VLS disconnect switches combine modular design, flexible mounting options, and dual UL 508/UL 98 certification to simplify industrial panel design and compliance. With a 63 A crossover point for space-versus-capacity optimization, standardized accessories, and an operating range of -25°C to +55°C, the VLS lineup supports safety, reliability, and inventory reduction across applications such as HVAC, solar, pumping, and material handling.