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EARTHING + LIGHTNING PROTECTION
The key to battery longevity lies in a thorough
understanding of the status of individual batteries
in a multi-battery pack in terms of their duty cycles
and load factors.
Battery maintenance should be at the top of a UPS
user’s priority list. A good maintenance regimen will help
prolong battery life while keeping a note of where the battery
is in its life cycle will provide an indication as to when failure is im-
minent.
Battery balancing
The prevalence of unexpected power outages in South Africa – often
longer than four hours – has exposed one of the Achilles’ heels of
standby power devices; the dramatically shortened lifespan of batter-
ies (including deep-cycle batteries) when subjected to full depletion
on a regular basis.
To help prevent premature battery failure, a new-generation,
battery management harness is a necessity. The ‘smart’ battery
technology in leading harness brands monitors and optimises the
performance and efficiency of individual batteries in a battery pack
on a 24x7 basis.
This is achieved by a dedicated, computerised battery balanc-
ing solution that automatically monitors data streams containing
information critical to the wellbeing of individual batteries, including
temperature, state of charge and depth of discharge. The tally of the
number of discharge/ charge cycles is recorded.
Using this data, the system’s battery performance is able to be
balanced and equalised. Should an individual battery’s operating
parameters not meet design specifications or fail for any reason
the battery is flagged for replacement – thus ensuring the integrity
of the pack.
The technology featured in a battery management harness not
only distributes and balances the battery load, but discharge and
charge regimes across all batteries in the pack can be monitored
on a minute-by-minute basis. Thus steps can be timeously taken to
ensure that no battery is compromised through over-cycling or a
malfunction of any kind.
UPS threats
Apart from battery failure, other serious threats to the smooth opera-
tion of a UPS system include a sudden ‘spike’ in the power supply.
Called transient spikes, they are likely to inflict serious damage to
the input side of a UPS – the filter/rectifier siting.
Regular maintenance regimens will most certainly
be able to determine whether damage has occurred
and remedial steps can be initiated. This applies to
almost all elements of a UPS system,
The scourge of Highveld weather, lightning, can do
serious damage to a UPS system and to the highly sensitive
computer systems it is tasked to protect. A common misconception
is that a UPS system constantly protects itself and the equipment
load from lightning strikes. If the amount of energy in the transient
(the lightning strike) is large enough, damage will occur. Surge sup-
pression devices, if installed, including metal oxide varistor (MOV)
devices are often compromised by lightning strikes.
As small as a two-rand coin or as large as a cool-drink can, capaci-
tors, like batteries, degrade over time. The effects of time may not be
apparent, but a single failure will have a domino effect, leaving the
other capacitors to work harder and fail sooner. Most UPS systems
contain as many as a dozen or more of these simple devices that
store and release electrical energy.
Dust is the enemy, steadily advancing to block filters and cause
progressive overheating of UPS systems. Regular monthly inspec-
tions are required to address this problem. Fortunately, filters are the
least most expensive components of an effective UPS maintenance
plan.
Contactor failure is another threat to UPS systems. Contactors,
which are also prime collectors of fine dust and other resistive par-
ticles, require regular inspection and cleaning to ensure optimum
performance and to guard against premature failures.
The failure-proofing of relays is not usually at the top of any
maintenance schedule, however, technically-aware UPS owners
understand that the sticking of welded relays may go unnoticed for
long periods of time. The problem is revealed only when emergency
change-of-state events occur. Appropriate inspection procedures are
able to detect problems before they arise.
Total cost of ownership
Selecting a UPS system that matches an organisation’s exact needs
is vital to UPS longevity. Consulting a knowledgeable provider with
experience in the UPS industry before making an investment is pru-
dent as is selecting a system that can organically grow in tandem
with the company’s expansion plans.
In this light, when budgeting for a UPS system, it is crucial to
consider the total cost of ownership (TCO) – rather than just the
Abbreviations/Acronyms
MOV – Metal Oxide Varistor
MTTR – Mean Time To Repair
TCO
– Total Cost of Ownership
UPS
– Uninterruptible Power Supply
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October ‘16
Electricity+Control