UPS (Backup your Security System)

Computers are the brains of todays security systems totally depend on the Computers and high end server.  Without that computer you can be in serious trouble.  For this reason a UPS is must for the protection of your critical security system.

A UPS or Uninterruptible Power Supply, is simply a battery backup system that will supply a steady flow of power during a power failure or brown-out.

Working of UPS :

                                              Fig: Explaining the flow of current with green colour.

Types of UPS: There are two main types of UPS systems; on-line and off-line.

(1)    An on-line system gets its name from the fact it is continuously rectifying the AC source being supplied from the wall outlet.  It first converts the AC power to DC power and then inverts the DC voltage back to AC thus serving “clean” power to a system.  This process is called double conversion or more commonly described as power conditioning.  These on-line UPS systems protect the majority of data centers and other critical loads.

(1)    An off-line systems operate in a standby mode.  The normal electric coming from an outlet will power the source directly under normal load conditions.  In these systems, there is no continuous power conditioning that takes place.  These UPS systems only operate when the normal AC source deviates from specified values.  Once this occurs the UPS system will supply clean power to the system load.

The role of a UPS is simply to protect systems from significant AC power variation being supplied from a utility.  Voltage sags are a major factor and represent over 98% of all power quality problems according to the Electric Power Research Distribution Power Quality Study.  Momentary and long term outages are also common problems.  Voltage swells are not a particularly significant concern.  Voltage sags and swells are defined as voltage that is more or less than 10% of the normal system voltage for one cycle.

Most of today’s computer systems are designed to meet the guidelines of the Information Technology Industry Council.  This states that equipment should continue to operate even with a 20 millisecond voltage drop to zero. 

Both an on-line and off-line UPS system will easily ensure that the voltage provided to the main system is within the ITIC guidelines. On-line and Off-line systems provide the same protection against these voltage excursions.  The true difference between the two designs is the transition time between the utility AC source and the battery source of the UPS.  Depending on the off-line UPS and the quality of that UPS some offer lag times as small as 2 to 4 milliseconds, ensuring there is almost no need for the on-line system. With any UPS you want to ensure against transient events (lightning), by using a transient voltage suppression system (TVSS), this is commonly referred to as surge protection.  Even though the UPS may have some surge protection, using a surge protector before the UPS is a good idea.  This will ensure that you also protect the UPS itself.  Surge protectors are easy to find and can be plug-in or hardwired.