UPS & Generator Setup for Your Office IT Infrastructure

Every South African business owner knows the frustration of load shedding. But beyond the inconvenience, sudden power loss poses real risks to your IT infrastructure—data corruption, hardware damage, and extended downtime.

A properly designed power backup system protects your investment and keeps your business running. This guide covers everything you need to know about UPS and generator systems for office IT infrastructure.

Understanding Your Power Backup Options

Uninterruptible Power Supplies (UPS)

A UPS provides instant battery backup when mains power fails. Key functions:

• Instant switchover: No interruption to connected equipment
• Clean power: Filters surges and voltage fluctuations
• Graceful shutdown: Time to save work and shut down properly
• Surge protection: Guards against damaging spikes

UPS Types:

Standby/Offline UPS

• Most affordable
• Small switchover delay (5-12ms)
• Basic surge protection
• Suitable for: Individual PCs, home offices

Line-Interactive UPS

• Better voltage regulation
• Faster switchover
• Automatic voltage regulation (AVR)
• Suitable for: Business workstations, small servers

Online/Double-Conversion UPS

• Zero switchover time
• Complete isolation from mains power
• Best protection for sensitive equipment
• Suitable for: Servers, network infrastructure, critical systems

Generators

Generators provide extended runtime during prolonged outages:

• Diesel generators: Reliable, economical for larger loads
• Petrol generators: More portable, suitable for smaller offices
• Inverter generators: Cleaner power, quieter, better for electronics

Generators alone aren't sufficient for IT—they take time to start and produce less stable power than batteries.

The Ideal Combination

For most offices, the optimal setup combines both:

1. UPS provides instant backup and clean power
2. Generator extends runtime beyond battery capacity
3. UPS conditions generator power for sensitive equipment

Calculating Your Power Requirements

Step 1: List All Equipment to Protect

Create an inventory:

Step 2: Determine Total Load

Add up the watts for everything you want to protect:

• Critical equipment: Servers, network gear, security systems
• Standard equipment: Workstations used during outages
• Optional equipment: Can be excluded to extend runtime

Step 3: Calculate Required UPS Capacity

UPS capacity is measured in VA (Volt-Amps):

Watts to VA conversion: VA = Watts ÷ Power Factor (typically 0.7-0.8)

Example:

• Total critical load: 650W
• VA required: 650 ÷ 0.7 = 928VA
• Add 20% headroom: 1,114VA
• Recommended UPS: 1,500VA minimum

Step 4: Determine Runtime Requirements

How long do you need the UPS to last?

• 5-10 minutes: Enough for graceful shutdown
• 15-30 minutes: Short outages, save work, basic continuity
• 30-60+ minutes: Extended operations, waiting for generator

Runtime depends on load and battery capacity. Manufacturers provide runtime charts.

Step 5: Generator Sizing (If Applicable)

For generator backup, size for:

• Total load of all equipment (including non-IT like lights, aircon)
• Starting surge requirements (some equipment needs extra power to start)
• Future growth capacity

Typical office needs: 5-15kVA depending on size

Setting Up Your UPS System

Choosing the Right UPS

For different scenarios:

Small Office (1-5 people):

• 1,500VA - 3,000VA line-interactive UPS
• Protects server (if any) and network equipment
• Desktops may or may not be protected

Medium Office (5-20 people):

• Multiple 3,000VA units or single 5,000VA+ unit
• All critical infrastructure protected
• Selected workstations on UPS

Server Room:

• Online/double-conversion UPS
• 5,000VA - 10,000VA or more
• Consider rack-mounted units
• Network management cards for remote monitoring

Installation Best Practices

Placement:

• Well-ventilated area (batteries generate heat)
• Away from direct sunlight
• Accessible for maintenance
• Not in areas prone to flooding

Wiring:

• Use dedicated circuits for UPS
• Match circuit breaker to UPS capacity
• Consider hardwired installation for larger units
• Proper earthing is essential

Load Distribution:

• Don't exceed 80% of rated capacity
• Balance load across outlets if multiple
• Never plug UPS into another UPS
• Avoid connecting laser printers (high surge)

Configuration

Shutdown Settings:

• Install UPS management software
• Configure automatic shutdown at low battery
• Set shutdown delay appropriate for your systems
• Test shutdown procedure

Alerts and Monitoring:

• Email notifications for power events
• SNMP for network monitoring integration
• Regular self-test schedules
• Battery health monitoring

Generator Integration

Automatic Transfer Switch (ATS)

An ATS automatically switches between mains and generator:

1. Detects mains failure
2. Signals generator to start
3. Waits for generator to stabilise (15-30 seconds)
4. Transfers load to generator
5. Monitors mains and switches back when restored

During transfer, the UPS bridges the gap.

Manual Transfer

For smaller setups, manual transfer is more affordable:

1. Generator starts (manually or auto-start)
2. Operator confirms generator is stable
3. Manual switch transfers load
4. Process reverses when mains returns

Important: Never connect generator to mains circuits without proper transfer switching—you could endanger utility workers and damage equipment.

Generator Best Practices

Installation:

• Outdoor location with weather protection
• Adequate ventilation for exhaust
• Fuel storage meeting regulations
• Noise considerations (neighbours, office workers)

Maintenance:

• Weekly test runs (15-30 minutes under load)
• Regular oil and filter changes
• Fuel management (diesel degrades, rotate stock)
• Annual professional servicing

Operation:

• Allow warm-up before applying full load
• Don't overload—respect rated capacity
• Monitor during extended operation
• Refuel safely (engine off, proper containers)

Network Equipment Protection

Often overlooked but critical:

Fibre/Internet Connection

Your fibre ONT and router need power to maintain internet:

• Small UPS (650VA-1,000VA) dedicated to network equipment
• Typically provides 1-3 hours of connectivity
• Enables mobile devices and laptops to stay connected

Network Switches and Firewalls

These should be on the main UPS or have dedicated protection:

• Central switches are single points of failure
• Firewalls protect network security
• Consider PoE switches (they power phones/WiFi)

WiFi Access Points

If WiFi is essential:

• Connect access points to UPS-backed switches (PoE)
• Or use individual PoE injectors on UPS power
• One access point may be sufficient during outages

Monitoring and Maintenance

Regular Testing

Monthly:

• Visual inspection of UPS units
• Check status LEDs
• Review logs for events
• Self-test execution

Quarterly:

• Extended runtime test
• Battery condition assessment
• Generator test run under load
• Procedure review

Annually:

• Professional UPS inspection
• Battery replacement assessment
• Generator servicing
• Full disaster recovery test

Battery Management

UPS batteries have limited life:

• Typical lifespan: 3-5 years
• Hot environments shorten life
• Deep discharges accelerate wear
• Monitor battery health metrics
• Replace proactively, not reactively

Documentation

Maintain records of:

• Equipment inventory and configurations
• Runtime calculations
• Maintenance logs
• Test results
• Vendor contacts

Common Mistakes to Avoid

Undersizing UPS: Running at high capacity reduces runtime and stresses batteries.

Ignoring Battery Health: Old batteries fail when you need them most.

No Generator Power Conditioning: Generator power isn't clean—equipment still needs UPS.

Protecting Everything Equally: Focus investment on critical systems, not every desk.

No Testing: Equipment that isn't tested will fail unexpectedly.

Professional Assistance

Designing and implementing power backup for IT infrastructure requires expertise. Get it wrong, and you could face data loss, equipment damage, or fire risk.

Dexani helps South African businesses design, implement, and maintain power backup solutions. We assess your requirements, recommend appropriate equipment, manage installation, and provide ongoing support.

Don't leave your IT vulnerable to load shedding. Contact Dexani today for a power backup assessment and ensure your business stays running when the grid doesn't.

Dexani is a Managed IT Services Provider helping South African businesses build resilient IT infrastructure.