21 July 2015
By Marco Da
Silva, Managing Director of Power Solutions, The Jasco Group
Given the current and very real power crisis
in South Africa, and the fact that it is set to continue for the foreseeable
future, a generator coupled with an Uninterruptable Power Supply (UPS) is fast
becoming essential equipment for both businesses and households. Minimising the
disruption caused by load shedding is the ultimate goal, and utilising a UPS in
conjunction with a generator can create seamless failover between utility and
backup power. However, power assurance solutions such as these are not enough
on their own, as even when utility power is running, it may be unstable. This
causes voltage fluctuations such as transients, harmonics, surges and dips that
can seriously damage sensitive electronic and computer equipment and cause data
corruption, not to mention shortening the lifespan of all appliances. An
Automatic Voltage Regulator (AVR), which offers power quality, in conjunction
with power assurance solutions, is the ideal solution for ensuring a consistent
supply of clean power.
When it comes to power assurance solutions,
each organisation will have its own unique requirements as well as challenges
with regard to electrical and environmental circumstances. While the majority
of organisations understand the need for a UPS to act as a bridge between
utility power and generator power, ensuring a smooth and seamless transition,
the role of the AVR is not as well understood. One of the most common
misconceptions for businesses looking to purchase a UPS is that it will
automatically include AVR functionality. The reality is that this is often not
the case, and while some UPS solutions do incorporate AVR, many do not, which
requires the AVR unit to be purchased separately. UPS’ with included AVR also
tend to have very basic AVR functionality, which is often limited in bandwidth
to deal with unstable mains, resulting in the UPS using batteries to ride these
situations out.
An AVR’s primary purpose is to stabilise
voltage fluctuations caused by unstable mains supply from the local utility.
While load shedding and power outages cause an instantaneous cut off of power,
even when power is available it is often not delivered at a stable voltage.
This has a number of implications. Firstly, dips in available power may cause
generators to start up unnecessarily and run even while utility power is
available. In addition, fluctuations in voltage can degrade the life of
electronic components, potentially causing premature failure, and can cause
data corruption on hard drives. Large surges can also burn equipment out,
causing instantaneous failure. An AVR not only adjusts voltages to safe levels,
it ensures a steady and constant power supply by automatically regulating the
voltage at the appropriate level, by the decline during the surge or the
increase when voltage drops in the power line.
An AVR will extend the life of sensitive
equipment. It will also ensure that the Automatic Mains Failure (AMF) panel on
generators, which is responsible for starting the generator when utility power
fails, does not activate unnecessarily. The AMF is typically set to start up if
more than 10% of the voltage is lost, however, in South Africa this is not an
uncommon occurrence and does not necessarily necessitate generator power. An
AVR will condition the power and prevent this from happening. An AVR can also be
installed in front of the UPS to ensure that the UPS does not go into battery
mode due to excessive high or low voltage, thereby extending the life of the
UPS batteries.
An AVR has many applications, and can be used
with any type of electrical equipment in a number of environments. These
include data centres and other IT infrastructure, communications solutions and
industrial equipment. An AVR can also be used in inductive applications, such
as low frequency equipment, heating and cooling systems, where a UPS is not
compatible. AVRs are either installed at the main distribution board or
directly in front of the connected equipment. AVRs can also be installed in
front of the UPS or the UPS bypass in online double conversion technologies so
should a static bypass occur one still enjoys stable voltage. Ensuring your
business obtains the right AVR solution for power quality, and implements these
solutions in the most appropriate manner, will require partnering with a
reputable power solutions provider. Such a provider will be able to effectively
assess, design and implement a compatible AVR solution depending on the
electrical and environmental circumstances of a particular business.