How to Use Two UPS: One Online and the Other as a Backup

How to Use Two UPS: One Online and the Other as a Backup

In critical power setups where uptime is non-negotiable, using two UPS systems—one as the primary online UPS and the other as a backup or secondary UPS—can provide enhanced protection, redundancy, and continuous operation even during failures. This dual-UPS strategy ensures mission-critical systems like servers, telecom, medical equipment, and banking infrastructure never lose power. Lento, a manufacturer of high-quality Online UPS systems, offers 10KVA and 30KVA DSP-based models ideal for such installations. With proper configuration and the right switchgear, you can build a fail-safe, smart, and reliable UPS backup system that suits industrial and commercial requirements.

Introduction

Power failures, voltage fluctuations, and sudden blackouts are among the most common causes of data loss, hardware damage, and business downtime. In sectors like healthcare, manufacturing, finance, and telecom, even a few seconds of power disruption can lead to major operational failures.

A standard Online UPS offers excellent protection, but in mission-critical environments, businesses often opt for dual-UPS configurations to ensure uninterrupted power continuity. One UPS handles the main load, while the other acts as a redundant backup that steps in automatically or manually in case of a primary UPS failure.

This blog explains how to effectively use two UPS units—an Online UPS and a backup UPS—and how Lento's UPS solutions are perfect for such high-reliability power designs.

Why Use Two UPS Systems?

Using two UPS units adds another layer of power security to the system. It’s especially useful in:

• Data centers
• Hospitals and laboratories
• Industrial automation
• Banking networks
• Broadcasting and telecommunications

Key Benefits:

• Redundancy: If one UPS fails, the other takes over.
• Load sharing (in advanced systems): Distribute load between two UPS units for longer runtime.
• Zero downtime: Maintenance or battery replacement can be performed without shutting down the system.
• Improved reliability: Adds robustness to high-availability infrastructure.

UPS System Types and Roles

Before setting up two UPS systems, it’s important to understand their roles:

1. Primary UPS (Online Type)

• Typically a DSP-based Online UPS like Lento’s 10KVA or 30KVA models.
• Offers zero transfer time, pure sine wave output, voltage/frequency regulation.
• Handles the critical load at all times.

2. Secondary or Backup UPS

• Can be Online, Line-interactive, or another type depending on budget and application.
• Remains in standby mode and powers the load only when the primary UPS fails or is under maintenance.

How to Configure Two UPS Systems Safely

There are three common configurations for setting up dual UPS systems:

A. Hot Standby UPS System

In this setup:

• The primary UPS supplies power to the load.
• The backup UPS is powered on but doesn’t supply the load unless the primary fails.
• A Static Transfer Switch (STS) is used to switch the load to the backup UPS in milliseconds.

Pros:

• Seamless transition
• Ideal for critical systems

Lento's 10KVA/30KVA Online UPS is ideal for the primary position here.

B. Manual Bypass to Secondary UPS

In this setup:

• A manual transfer switch is used.
• The operator manually switches to the backup UPS during servicing or failure.

Pros:

• Cost-effective
• Simple to implement

Cons:

• Requires manual intervention

This is commonly used in medium-sized commercial buildings, banks, and telecom installations.

C. Parallel Redundant UPS Configuration (N+1)

In this setup:

• Two Online UPS units run in parallel, both sharing the load.
• If one UPS fails, the other continues to support the full load.

Pros:

• No single point of failure
• Increased reliability

Cons:

• Costlier and complex
• Requires same UPS models and battery banks

Lento's high-efficiency Online UPS models with DSP control, SNMP monitoring, and zero transfer time are highly suited for such setups.

Safety and Design Considerations

Using two UPS systems requires more planning than a single unit setup.

Key Guidelines:

1. Match Output Ratings: Ensure both UPS units are of equal or compatible voltage, frequency, and power rating.
2. Use Isolation: Avoid direct electrical connection between two UPS outputs without a static or mechanical switch.
3. Monitoring and Alarms: Integrate alarm systems to signal when the primary UPS fails and backup engages.
4. Battery Management: Maintain battery health for both UPS units. Use Lento batteries for seamless performance.
5. Test Regularly: Schedule routine testing for backup UPS and switching systems.

Lento UPS Systems – Ideal for Dual UPS Setups

Lento manufactures industrial-grade Online UPS systems specifically designed for mission-critical power environments. With DSP-based sine wave technology, pure sine output, and advanced protection features, Lento UPS systems are ideal for use as both primary and secondary power sources.

Available Lento UPS Variants:

• 10KVA / 180VDC
  • Compact, smart design
  • Built-in LCD monitoring and protection
• 30KVA / 360VDC
  • Inbuilt isolation transformer
  • Handles phase imbalance
  • Pure sine wave output regulated to ±2%

Common Features:

• Zero transfer time
• Generator compatibility
• Auto shutdown software
• SNMP/web/GSM monitoring (optional)
• Short circuit, high temp, and battery protections

Compatible Battery Solutions from Lento

A UPS setup is incomplete without reliable batteries. Lento offers high-efficiency, long-life batteries ideal for UPS systems:

• Tubular Lead Acid Batteries (C10/C20 rated)
  • 150Ah, 200Ah, 240Ah, 260Ah
• AGM/VRLA Batteries
  • 42Ah, 65Ah, 100Ah, 150Ah, 200Ah
• Lithium-Ion Batteries (51.2VDC)
  • 100Ah, 150Ah, 200Ah, 300Ah

These batteries are optimized for UPS runtime, maintenance-free operation (AGM/lithium), and long service life.

Conclusion

For critical applications that cannot afford even a second of power interruption, using two UPS systems—a primary Online UPS and a backup unit—ensures maximum reliability and protection. Whether you're managing a data center, medical lab, or telecom infrastructure, a dual UPS setup with proper configuration and quality components adds unmatched peace of mind.

Lento’s 10KVA and 30KVA DSP-based Online UPS systems are engineered for such needs, offering high efficiency, comprehensive protection, and seamless integration with backup power setups. Combined with Lento’s range of batteries and monitoring tools, you can build a power system that is robust, smart, and fail-safe.

Call to Action

Looking to design a dual-UPS power system for your facility? Choose Lento’s advanced Online UPS systems and batteries to ensure continuous, protected, and clean power supply for your business. Whether you’re a B2B distributor or an infrastructure provider, contact Lento today to get expert advice, competitive pricing, and dependable power solutions tailored to your needs.

FAQs

1. Can two UPS systems be used together?
Yes. Two UPS units can be configured in a primary and secondary setup or used in parallel for redundancy. This is common in data centers, banks, and hospitals.

2. How do I connect two UPS systems for redundancy?
To connect two UPS systems, you can use a static transfer switch for automatic switchover or a manual bypass switch for controlled changeover. Proper load balancing and voltage matching are essential.

3. What happens if the primary UPS fails?
If the setup includes a backup UPS, the system will switch the load to it either manually or automatically, ensuring no disruption in power to critical devices.

4. Should the two UPS units be the same brand and model?
For parallel (N+1) redundancy, it is recommended that both UPS units are the same brand and model to ensure synchronization and compatibility. Lento UPS systems are ideal for such setups.

5. Can I use a Lento UPS as both primary and backup?
Absolutely. Lento’s Online UPS models are designed for mission-critical use and can function effectively as either primary or backup systems in redundant configurations.