How to Improve Availability Of UPS System?

Network/server UPS systems offer outstanding power protection, but they shouldn’t stop there. They should also incorporate high-availability and fault-tolerance features that help you avoid network downtime, which can cost an average of $70,000 per hour for midsize businesses.

On-line Operation 

Network/server UPS systems that use on-line operation and continuous double conversion provide the best protection and most reliable power available for critical systems. The double conversion process isolates equipment from power problems on the AC line and delivers ideal output 24x7.

Hot-Swappable Power Modules 

Traditional UPS systems require you to power down and disconnect your equipment during a UPS repair. Before you can restore productivity, you’ll need a repair technician to install the new UPS system and you’ll need to reconnect, power up and test all your equipment. That process can require up to two hours of costly and inconvenient system downtime.

Some network/server UPS systems can eliminate system downtime during UPS maintenance and repair. They include one or more hot-swappable power modules and a detachable bypass PDU. You can completely remove and replace the power modules while the bypass PDU keeps your critical systems up and running without interruption.

Hot-Swap PDUs 

Hot-swappable power modules are not usually found on UPS systems smaller than 5,000 VA, but you can make some smaller UPS systems (≤3,000 VA) hot-swappable by adding an external hot-swap PDU. The hot-swap PDU, also known as a bypass PDU, includes dual power inputs and a manual transfer switch. You can use the switch to select between UPS power and utility bypass power.

Power Redundancy

Many network/server UPS systems can be configured to provide redundant backup power, and some models have built-in redundancy. Models with two hot-swappable power modules automatically provide N+1 redundancy when the connected equipment load is ≤50% of capacity. (The maximum load for N+1 redundancy is equal to the capacity remaining when one power module has been removed. That would be 66% for three power modules, 75% for four, 80% for five and so on.) If one of the power modules requires maintenance, repair or replacement, your equipment still receives conditioned power and battery backup. All the power modules can also be hot-swapped at once without interrupting equipment operation, which will be supported by the bypass power source.

You can provide full backup power redundancy to devices that have redundant power supplies by connecting each power supply to a separate UPS. Ideally, the UPS systems should also be connected to separate supply circuits and utility sources. For single-cord devices that do not have redundant power supplies, you can connect dual on-line UPS systems to a PDU that has an automatic transfer switch (ATS). The ATS PDU will switch to the secondary power source if the primary power source fails.

Wide Input Voltage Range 

Network/server UPS systems that can correct a wide range of input voltages without switching to battery can reduce battery wear by as much as 40%. This reduces battery life-cycle costs and ensures that batteries are more likely to provide reliable service during outages.

Automatic Bypass 

Network/server UPS systems with an automatic AC bypass route utility power to your equipment and keep it powered if the UPS experiences an extended overload or internal fault.

Hot-Swappable Batteries

All internal and external batteries of network/server UPS systems should be hot-swappable. You can replace hot-swappable batteries without powering down the UPS system or your equipment.

Overload Capacity Some network/server UPS systems can handle overloads up to 150% for brief periods to support higher inrush currents at startup and fluctuating power demands during use. They can also transfer to bypass dynamically to sustain operation during higher and longer overloads for extended periods. This capability allows UPS systems to handle the repeated inrush spikes of heavy inductive loads without shutting down.