Short answer: the nine common power problems are power failure, sags, surges, brownouts, spikes, line noise, frequency drift, switching transients and harmonic distortion. A standby UPS (Ninja) handles the first three, a line-interactive UPS (SafeGuard, Defender, Commander) five, and an online UPS (Centurion) all nine.
Quick pick: PCs and NBN gear on metro power: line interactive. Servers, generator sites, factories and poor rural supply: online. Tight spaces such as switchboards and kiosks: the Ninja standby UPS.
ARC IP Networks is a trusted PowerShield supplier in Australia: genuine stock at competitive prices, with the full PowerShield Australian warranty, Australia-wide delivery and trade pricing.
The 9 power problems at a glance
Which UPS type PowerShield lists as addressing each problem:
Swipe the table sideways to compare all models →
| Problem | What it is | Standby (Ninja) | Line interactive (SafeGuard, Defender, Commander) | Online (Centurion) |
|---|---|---|---|---|
| Power failure (blackout) | Complete loss of mains power. | Yes | Yes | Yes |
| Power sag | Short-term low voltage, often lasting a fraction of a second. | Yes | Yes | Yes |
| Power surge | Short-term high voltage. | Yes | Yes | Yes |
| Brownout | An extended period of reduced voltage. | No | Yes | Yes |
| Spike | An instant voltage increase that PowerShield notes can exceed 5,000 volts. | No | Yes | Yes |
| Line noise | Radio-frequency (RFI) and electromagnetic (EMI) interference riding on the supply. | No | No | Yes |
| Frequency drift | An intermittent change in the mains frequency away from 50 Hz. | No | No | Yes |
| Switching transient | A very fast voltage increase, shorter than a spike. | No | No | Yes |
| Harmonic distortion | Deviation of the waveform away from a pure sine wave. | No | No | Yes |
Source: PowerShield Product Catalogue, "Choose your UPS > Problems addressed".
1–3. Power failure, sags and surges: every UPS handles these
Power failure is the one everyone thinks of: the lights go out. Sags are short dips in voltage, usually when something big starts up on the same network, such as an air conditioner or a pump. Surges are the opposite, a short rise in voltage when a large load switches off.
Even the most basic UPS switches to battery when power fails and has surge suppression built in. For a sense of scale, the Ninja Slimline is rated at 760 J / 5,000 A of surge protection and the Defender 1200VA at 936 J / 19,500 A (PowerShield datasheets).
- Australian causes: Storm damage to lines, lightning, bushfire and flood outages, grid overloads on hot days, vehicles hitting poles.
- Sags: Large loads starting (air conditioners, compressors, pumps, lifts), network switching, equipment faults.
A standby UPS such as the Ninja Slimline (PSLN600) covers these three in a 42 mm slim case for switchboards, irrigation panels and menu boards. It does not regulate voltage while it is on mains.
4–5. Brownouts and spikes: line interactive and above
A brownout is a long period of low voltage rather than a momentary dip. In Australia it shows up on peak-demand days and at the end of long rural feeders. A spike is an instant jump in voltage, and PowerShield notes it can exceed 5,000 volts when lightning hits the network.
A line-interactive UPS adds automatic voltage regulation (AVR): a transformer boosts low voltage and bucks high voltage while the UPS stays on mains. That fixes a brownout without draining the battery, which in turn protects battery life. PowerShield fits AVR to SafeGuard, Defender and Commander, and calls line interactive its minimum standard level of protection.
- SafeGuard and Defender: AVR with a simulated sine wave on battery, for PCs, NBN gear and POS.
- Commander Tower and Commander RT: AVR with a pure sine wave, for workstations and NAS units with active-PFC power supplies.
If you only need to fix low or high voltage and do not need battery backup, the VoltGuard AVR (PSVG1500) regulates a 184–284 VAC input to 240 VAC ±10% for up to 750 W.
6–9. Line noise, frequency drift, transients and harmonics: online only
The last four problems are about the quality of the power rather than how much of it arrives, and only an online double-conversion UPS removes them. It converts all incoming AC to DC and then builds a new, clean AC waveform, so the load never sees the incoming supply.
| Problem | What it is | Common Australian causes |
|---|---|---|
| Line noise | Radio-frequency (RFI) and electromagnetic (EMI) interference riding on the supply. | Transmitters, heavy machinery, large office machines, variable-speed drives on the same circuit. |
| Frequency drift | An intermittent change in the mains frequency away from 50 Hz. | Generators as they are loaded and unloaded: mine sites, farms, construction, events and backup generators. |
| Switching transient | A very fast voltage increase, shorter than a spike. | Indirect lightning strikes and network switching. |
| Harmonic distortion | Deviation of the waveform away from a pure sine wave. | Large machinery, computers and office equipment drawing non-linear current. |
Definitions: PowerShield Product Catalogue. Causes: PowerShield, plus ARC IP Networks site experience.
This is why PowerShield recommends Centurion for harsh environments. On the Centurion RT the transfer time from mains to battery is zero and the input frequency window is 40–70 Hz, so a generator that drifts does not force it onto battery (PowerShield datasheet).
- Centurion RT: rack or tower, expandable with battery modules.
- Centurion Tower: for offices and regional sites without a rack.
- Centurion RT LiFePO4: lithium iron phosphate for hot cabinets and a longer battery life.
Standby vs line interactive vs online: PowerShield's comparison
Swipe the table sideways to compare all models →
| Standby | Line interactive | Online double conversion | |
|---|---|---|---|
| PowerShield models | Ninja Slimline | SafeGuard, Defender, Gladiator, Commander | Centurion, Centurion Pro, Platinum |
| Problems addressed | 3 of 9 | 5 of 9 | All 9 |
| Backup duration | Short | Short to medium | Long |
| Voltage regulation | On battery only | Limited | Permanent |
| Line filtering (surges) | Limited | Limited | Permanent |
| Frequency regulation | No | No | Yes |
| Typical usage | Small office | Small office / entry-level enterprise | Harsh environment |
| Protection level | Limited | Medium | High |
Source: PowerShield Product Catalogue, "Choose your UPS". PowerShield calls standby its "bronze" level, line interactive its minimum standard level, and online double conversion "the ultimate protection of critical equipment".
Our online vs line-interactive guide explains how each topology works, transfer times and pure vs simulated sine wave.
Which protection does your Australian site need?
Swipe the table sideways to compare all models →
| Site and symptoms | Problems to solve | UPS type | PowerShield pick |
|---|---|---|---|
| Home office or shop on metro power: occasional outages | Failure, sags, surges | Line interactive | PSG750 or PSD650 |
| Switchboard, irrigation or signage panel with no room | Failure, sags, surges | Standby (slimline) | PSLN600 |
| Lights dim when the air conditioner starts | Sags, brownouts | Line interactive | PSD1200 or PSCM1100 |
| Storm-prone area (summer lightning) | Spikes, surges, failure | Line interactive or online | PSCM2000 or PSCERT2000 |
| Regional property at the end of a long line | Brownouts, sags, frequent short outages | Online | PSCERT2000 or PSCE2000 |
| Generator-backed site: mine, farm, event, construction | Frequency drift, transients | Online | PSCERT3000 or PSCE3000 |
| Factory floor beside machinery and drives | Line noise, harmonics, transients | Online | PSCERT3000 or PSCE3000 |
| Server room or comms rack that must not drop | All nine | Online | PSCERT1000 to PSCERT6000L |
ARC IP Networks suggestions. Size the UPS on watts first, then runtime.
Next step: size it with our UPS sizing guide, or check runtimes in the PowerShield runtime chart.
When a surge-protected power board is enough
For equipment that can simply switch off in an outage, such as a TV, a printer or a desk lamp, a good surge board is cheaper than a UPS. The ZapGuard 5-outlet (PSZ5U2) and ZapGuard 8-outlet (PSZ8U2) are tested to AS/NZS 3105 and rated at 1,400 J and 2,100 J of surge energy, with USB charging. They do nothing for outages, brownouts or the online-only problems.
PowerShield protection by problem
Live Australian pricing (inc. GST) and availability are on each product page.
Standby LiFePO4 UPS, 42 mm slim: failure, sags and surges.
Online double conversion: all nine problems, zero transfer.
Online with lithium iron phosphate batteries.
Voltage regulation without a battery, for brownouts and high voltage.
Why buy PowerShield from ARC IP Networks
ARC IP Networks is a trusted PowerShield supplier in Australia: genuine stock at competitive prices, with the full PowerShield Australian warranty, Australia-wide delivery and trade pricing.
- Genuine PowerShield stock, covered by the PowerShield Australian warranty: 2 years advance replacement on SafeGuard and Defender; 2 years on single-phase Commander and Centurion, extended to 3 years when you register the UPS with PowerShield; 5 years on Centurion RT LiFePO4 and the Ninja Slimline.
- Help sizing the UPS, battery modules and network cards for your actual load, from a team that also designs networks, comms racks and surveillance systems.
- Australia-wide delivery, trade pricing for installers and IT providers, and quotes for multi-site rollouts.
Browse the full PowerShield range at ARC IP Networks or call 1300 100 440.
Common questions
Straight answers from the ARC IP Networks team. Last reviewed October 2026.
PowerShield lists nine: power failure, power sags, power surges, brownouts, spikes, line noise, frequency drift, switching transients and harmonic distortion.
A sag is a short-term dip in voltage, often when a large load such as an air conditioner starts. A brownout is an extended period of reduced voltage, typically when demand exceeds the local network's capacity.
A surge is a short-term rise in voltage, for example when a large load switches off. A spike is an instant increase that can exceed 5,000 volts, usually from lightning striking the network.
Only an online double-conversion UPS regulates frequency. PowerShield Centurion RT accepts a 40–70 Hz input and rebuilds a stable output, so generator frequency drift does not reach the load.
An online double-conversion UPS, such as the PowerShield Centurion range. PowerShield lists it as addressing all nine power problems, against three for a standby UPS and five for a line-interactive UPS.
Usually, yes. On metro power a line-interactive UPS such as the PowerShield SafeGuard or Defender covers outages, sags, surges, brownouts and spikes, which are the problems most homes and small offices see.
A surge-protected power board only handles surges and spikes. If the equipment must keep running or shut down safely in an outage, such as a PC, NAS, NBN gear or a phone system, you need a UPS.
ARC IP Networks is a trusted PowerShield supplier in Australia: genuine stock at competitive prices, with the full PowerShield Australian warranty, Australia-wide delivery and trade pricing. Order online at arcip.com.au or call 1300 100 440 for help sizing a UPS or for a quote.
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