SecurityArena

Power Supply

Electrical Power Definitions

• Ground The pathway to the earth to enable excessive voltage to dissipate.
• Noise Electromagnetic or frequency interference that disrupts the power flow and can cause fluctuations.
• Transient noise Short duration of power line disruption
• Inrush current The initial surge of current required when there is an increase in power demand.
• Clean power Electrical current that does not fluctuate.
• Fault Momentary power loss/outage.
• Blackout Complete / Prolonged loss of power.
• Sag Momentary low voltage
• Brownout Prolonged low voltage
• Spike Momentary high voltage
• Surge Prolonged high voltage
• EMI Electromagnetic interference
• RFI Radio frequency interference

UPS. An uninterruptible power supply (UPS), also known as a battery back-up, provides emergency power and, depending on the topology, line regulation as well. It differs from an auxiliary or emergency power system or standby generator, which does not provide instant protection from a momentary power interruption.

• Offline / Standby UPS. With this type of UPS, a user's equipment is normally connected directly to incoming utility power. And UPS is activated as the main power fails.  It is more cost effective, least secure and batteries life is increased.
• Line-interactive. The Line-Interactive UPS is similar in operation to a Standby UPS, but with some additional features. This type of UPS is able to tolerate continuous under voltage brownouts and over voltage surges without consuming the limited reserve battery power.
• Online systems. Power is drawn by the system through a bank of batteries all the time. The Online UPS is ideal for environments where electrical isolation is necessary or for equipment that is very sensitive to power fluctuations. It is more costly and batteries life is less.
• DC power / Rectifier. These normally have typical protection time of Several hours. A UPSUPS, except that it does not need an output inverter, and often the powered device does not need a power supply. Many systems used in telecommunications use 48 volt DC power, because it is not considered a high-voltage by most electrical codes and is exempt from many safety regulations, such as being installed in conduit and junction boxes. designed for powering DC equipment is very similar to an online

Backup power Supply. Backup power supplies are necessary when there is a power failure and the outage will last longer than a UPS can last. Backup supplies can be a redundant line from another electrical substation or from a motor generator and can be used to supply main power or charge the batteries in a UPS system.

Voltage regulators and line conditioners. These can be used to ensure a clean and smooth distribution of power by tolerating continuous under voltage brownouts and over voltage surges.

Things to Remember for Electrical Power

• Plug in every device to a surge protector to protect from excessive current.
• Shut down devices in an orderly fashion to help avoid data loss or damage to devices due to voltage changes.
• Employ power line monitors to detect frequency and voltage amplitude changes.
• Use regulators to keep voltage steady and power clean.
• Protect distribution panels, master circuit breakers, and transformer cables with access controls.
• Provide protection from magnetic induction through shielded lines.
• Use shielded cabling for long cable runs.
• Do not run data or power lines directly over fluorescent lights.
• Use three-prong connections and adapters if using two-prong cables.
• Do not plug outlet strips and extension cords into each other.