- Ken Koty, sales engineer for PDU Cables (http://www.pducables.com/) and former
data center facilities manager for Thomsen Reuters, says:
Increased
resistance and heat are the primary reasons most electrical components
fail. Before electrical components fail,
they heat up. Infrared scanning is used
to inspect electrical equipment because excess heat is usually the first sign
of trouble. Loose connections,
imbalanced and or overloaded circuits, defective breakers, damaged switches,
faulty fuses, and material defects all lead to equipment failure. Using infrared scanning as an early warning
tool for potential electrical equipment/system failure is an important part of
maintaining mission critical uptime.
Why Infrared Scanning
Increased
resistance and heat are the primary reasons most electrical components
fail. Before electrical components fail,
they heat up. Infrared scanning is used
to inspect electrical equipment because excess heat is usually the first sign
of trouble. Loose connections,
imbalanced and or overloaded circuits, defective breakers, damaged switches,
faulty fuses, and material defects all lead to equipment failure. Using infrared scanning as an early warning
tool for potential electrical equipment/system failure is an important part of
maintaining mission critical uptime.
Infrared Scanning Responsibilities
With
the cost of infrared equipment dropping all the time, buying and using even low
end equipment can generate tremendous cost savings.
I
believe that every time an electrical panel is accessed, it should be infrared
scanned. Anyone authorized to work in an
electrical panel or high voltage cabling needs to be trained on infrared
scanning.
If
any hot spots are found or any components are outside of normal operating
temperatures, an electrician or facilities supervisor needs to trouble shoot
the problem.
Infrared Scanning the Electrical Panel
Electrical
switchgear and panels are the lifeblood of a data center. Without it, equipment failure is
immediate. Infrared scanning can
identify problems prior to failure, allowing you to take proactive steps to
prevent costly and sometimes dangerous electrical outages.
If
you are a dual powered or utilizing redundant power sources, anytime you switch
over power from primary to a backup power source infrared scan the switchgear
and backup PDU/RPP electrical panel boards and branch circuits for excessive
heat. Testing while under load will tell
you if there has been any degradation in the system components that could lead
to future equipment failure and a possible outage.
Open
and scan the electrical panel and look for hot spots. Loose or week connections between breakers
and the main panel bus and other deficiencies including overloaded circuits,
load imbalances, harmonic problems and defective electrical components can all
contribute to a thermal scan heat signature.
When
a hot spot is identified, amp probe the circuit to measure the draw. Calculate loads to determine if the problem
is related to excessive load to one or a number of circuits. If the draw is less than 80% of the circuit capacity,
focus your attention on the circuit breaker or wiring connections to the
electrical panel. Check for loose or
week connections between a breaker and the main panel bus. Systematically work through the components
(testing and replacing if necessary), and electrical connections (checking for
loose connections and tightening if possible) until the problem is isolated and
resolved. If the draw exceeds 80% of the
circuit capacity, back track to the draw source. Has additional equipment been added to the
circuit?
Anytime
someone needs to access an electrical panel, power distribution unit or remote
power panel, they should infrared scan the branch circuits and breakers for
excessive heat. Even if you find
yourself in an electrical panel every week, it only takes a few seconds to scan
and determine if a problem exists. Though
it’s unlikely that screws have loosened in the past week, they do loosen up
over time.
More
likely, in a busy data center it is common for IT to have added new servers
into an existing rack without telling facilities management, increasing the
load on a 20 amp circuit from 16 to 18 or 19 amps, pushing that circuit over
the NEC guidelines of 80% of amp capacity, if it is a under load, meaning it is
energized continuously for three or more hours.
I
used to tell our IT people that just because there are outlets in a power strip
doesn’t mean there is electrical capacity on the circuit to support the added
equipment. Remember to ask before you
plug in. Regardless of my best efforts
to be informed of all new equipment installation into the data center, I’ve
personally learned about newly installed equipment when amp probing a circuit
to resolve hot spots after an infrared scan of a circuit panel.
I
also recommend that anytime someone installed or replaced a branch circuit
breaker, you should infrared scan it for problems. You don’t always have to wait for the circuit
to trip or fail to identify a potential problem. The infrared scan can tell you right away if
the breaker or wires are properly secured or if the installation dislodged
adjacent wires.
Summary
Infrared
scanning is a safe, non-evasive proactive method of detecting potential
failures in your mission critical infrastructure prior to them actually causing
an outage. Infrared scanning can be used
to identify any number of possible electrical problems in and around the data
center including; CRAC/CRAH units (loose connections to warn bearings), UPS
systems and battery backups, diesel generators, transformers and
switchgear.
Remember,
early detection allows maintenance personnel to take corrective action before a
component fails, minimizing damage to the components and reducing repair
cost. Infrared scanning of electrical
components and systems should be part of any preventative maintenance program
and performed on a routine basis. The
use of infrared scanning to detect early indications of system failure is a
preemptive measure that can minimize equipment breakdown and downtime.
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