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Power is security

The uninterruptible power supply (UPS), is self explanatory and simple, yet complex and involved. We are often asked what the purpose of a UPS is and why one should pay more for a UPS than an inverter, which can do a similar job.

How does a UPS work?

Your UPS connects to your equipment such as computers, servers, laptops, etc, then regulates the incoming power to keep it as close as possible to 230 V, or with 3-phase power, 400 V.

With the current power grid being old, overloaded and in most cases unmaintained, most electricity users today experience various power conditions such as low/high voltages, spikes, surges, dips and brownouts. The main purpose of an UPS is to protect your equipment against these voltage conditions.

Irregular voltage conditions strain your electronic components and cause them to fail prematurely. Devices such as computers and DVRs (digital video recorders) may experience complete loss of data or corrupted data. UPSs are perfect for these devices as it allows you 10 or more minutes to shut down your device after a power failure. Should you not be in front of the device at the time of the power failure, the software will shut the system down for you. Surge protection on UPSs is standard, so you can rest assured that the incoming surges will be nipped by the internal MOV (metal oxide varistor).

Definitions

Voltage

Low voltage is considered to be a continuously low input voltage for extended periods of time. They are normally caused when substations are overloaded; this overload can cause a drop in the incoming voltage and this in turn can cause equipment to switch off at irregular times. High input voltages are caused if your input voltage is above the nominal input voltage and can be caused by the same conditions.

Surge

Surges are sudden short increases in voltage. Surges are normally caused by the switching off of heavy duty equipment.

Dips

Dips are the opposite of surges. A dip normally occurs when heavy duty equipment is switched on.

Blackouts/brownouts

These occur where there is a total loss of power. Durations of your typical power failures are 2–4 hours, however it is becoming more regular that power outages exceed 4 hours.

Battery backup

This depends on the particular UPS. A standard UPS will supply you 10 to 30 minutes. Some clients feel a need for longer backup times such as 1 to 12 hours.

UPS or inverter?

Both units have battery backup time where the units can run for extended periods without power. What are the main differences?

A UPS protects against surges, dips, spikes, low/high voltages and brownouts (commonly known as power failures). The typical UPS has 0 second switch-over time, where the entry-level units have 4 to 6-millisecond switch-over time.

Inverters protect against brownouts. In some cases, there may be surge protection. Switch-over time is anything from 8 to 10-milliseconds. The switch-over time is sometimes too long for electronic devices and may cause them to restart.

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