Vertiv Liebert Maintenance Bypass Cabinet 20KVA | 208V/120V - (3) L14-30R

The Vertiv Liebert Maintenance Bypass Cabinet 20KVA (VMBC-20KMVRT4U) is a purpose-built solution designed to simplify UPS maintenance and service for Vertiv Liebert GXT5 15-20kVA and APS 1/2/5/6 UPS models. With a rugged,4U rack-mount enclosure and integrated bypass functionality, this cabinet provides a safe, reliable bypass path that keeps critical loads powered while technicians service or replace the UPS. It’s the ideal accessory for data centers, server rooms, and other facilities where uptime matters, delivering seamless maintenance without compromising protection or performance.

• Safe maintenance bypass: The built-in bypass switch routes power around the UPS, enabling maintenance or replacement without interrupting downstream loads. This essential feature keeps critical systems online and reduces downtime during service windows.
• Designed for Liebert GXT5 and APS UPS models: Specifically engineered for Liebert GXT5 15-20kVA and APS 1/2/5/6 architectures, ensuring a compatible, streamlined integration into existing power protection infrastructure.
• 20 kVA output capacity with 208V/120V compatibility: The cabinet supports 20 kVA of power distribution, compatible with standard 208V/120V electrical environments common in data centers and mission-critical spaces.
• Three L14-30R receptacles for flexible distribution: The enclosure provides (3) L14-30R outlets to distribute power to connected equipment, enabling efficient load management and balanced distribution during both normal operation and maintenance.
• Rugged, service-friendly enclosure: A durable, front-accessible cabinet designed for safe maintenance operations, easy wiring, and rapid serviceability in busy data center environments.

Technical Details of Vertiv Liebert Maintenance Bypass Cabinet 20KVA

• Model: VMBC-20KMVRT4U
• Power rating: 20 kVA output capacity
• Input/Output voltage: 208V / 120V compatible
• Receptacle configuration: (3) L14-30R outlets for load distribution
• Enclosure: 4U rack-mount maintenance bypass cabinet
• Compatibility: Designed for Vertiv Liebert GXT5 15-20kVA and APS 1/2/5/6 UPS models
• Purpose: Provides a dedicated bypass path to isolate the UPS for maintenance while continuing to feed critical loads
• Application: Data centers, server rooms, and other configurations requiring reliable downtime protection during UPS service

How to install Vertiv Liebert Maintenance Bypass Cabinet 20KVA

Installing the Vertiv Liebert Maintenance Bypass Cabinet 20KVA should be performed by qualified personnel with electrical safety training. Begin by reviewing the product manual and the specific installation guidelines for VMBC-20KMVRT4U to ensure all compliance and safety requirements are met. The installation process is designed to integrate into existing Liebert GXT5 15-20kVA or APS UPS configurations with minimal disruption to ongoing operations.

• Step 1 — Plan and verify credentials: Confirm that your site voltage matches the cabinet’s 208V/120V configuration and verify space, rack mounting compatibility, and clearance for service access. Ensure you have the appropriate maintenance window and notify affected teams before commencing work.

• Step 2 — Power down and isolate the UPS: Follow your facility’s shutdown procedures to safely de-energize the UPS. Use appropriate lockout/tagout procedures to prevent accidental re-energization during installation.

• Step 3 — Mount and position the MBC: Install the VMBC-20KMVRT4U in the designated rack position near the UPS, ensuring proper alignment and adequate ventilation. Route wiring channels for clean, protected cabling and minimize bend radii for long-term reliability.

• Step 4 — Connect input, bypass, and outputs: Connect the cabinet’s input to the mains supply and wire the bypass path according to the manual. Route load connections through the (3) L14-30R receptacles, ensuring correct phase balance and adequate circuit ratings for the connected equipment.

• Step 5 — Validate and test: Re-energize the system and perform a controlled bypass test under guidance from the maintenance manual. Verify that loads remain powered when the UPS is taken offline and confirm voltages, protection devices, and alarms are functioning correctly.

• Step 6 — Documentation and handoff: Record installation details, including wiring routes, receptacle assignments, and test results. Update facility drawings and security logs as needed and brief operations staff on daily operation and maintenance procedures.

Frequently asked questions

• Q: What is a maintenance bypass cabinet?

  A: A maintenance bypass cabinet provides a dedicated bypass path that allows technicians to service or replace the UPS without interrupting power to connected loads. It keeps critical systems online during UPS maintenance by routing power through an alternate path.

• Q: Which UPS models are compatible with the Vertiv Liebert Maintenance Bypass Cabinet 20KVA?

  A: It is designed for Vertiv Liebert GXT5 15-20kVA and APS 1/2/5/6 UPS models, ensuring a seamless integration with existing Liebert power protection infrastructure.

• Q: How many receptacles does the cabinet provide?

  A: The cabinet features three L14-30R outlets to support flexible distribution of connected loads during maintenance and normal operation.

• Q: What voltage is supported?

  A: The unit supports 208V/120V configurations, aligning with common data center electrical standards for Liebert UPS systems.

• Q: Is installation required to be performed by a licensed electrician?

  A: Yes. Because this equipment interfaces with high-voltage power systems and critical loads, installation and commissioning should be performed by qualified electrical professionals following manufacturer instructions.

• Q: Does the maintenance bypass cabinet guarantee uninterrupted load during maintenance?

  A: When properly configured and tested, the bypass path allows continued power delivery to connected loads while the UPS is serviced, minimizing downtime and preserving uptime for essential equipment.