Page 7 - EngineerIT September 2022
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• Prior to de-tanking we have already identified possible reasons There are various other tests which can be deployed as part
for failure; however it won’t be conclusive until the active unit of oil conditioning, these can be discussed with your preferred
has been inspected too. De-tanking will reveal the condition service provider; ArmCoil deem these as being the most effective
of the active unit and visual inspections are also done on the early warning signs of a larger problem which can most likely be
condition of the inside of the tank. remedied if diagnosed early. n
• By correctly determining the cause of failure, end users can
implement or mitigate for upgraded protection or in some
case, add protection. There are so many reasons for these Who is Armcoil?
failures hence it a very good idea to employ one or two well
recognized or accredited repair facilities/consultants who can ArmCoil is an OEM company for distribution transformers,
assist in decisive reactive maintenance. The ideal position for MVS under our brand ACEM (ArmCoil Electric Machines).
all end users is to be in a preventative maintenance program or
employ good maintenance technicians and managers. ArmCoil also owns a fully equipped facility for the
manufacturing, repairs and maintenance of Medium Voltage
systems such as:
• Power, Distribution, Rectifiers, Furnace and other custom
type transformers and their associated equipment.
• MV & DC Electric Motors and their associated equipment.
Other products on offer include large power transformers and
Cast Resin Type Transformers (CRT’s) and medium to large MV
Electric Motors.
www.armcoil.co.za | sales@armcoil.co.za |+27 11 763 2351
Typical ONAN transformer oil test guidelines for effective condition monitoring:
OIL TEST REASON FOR TEST
DISSOLVED GAS ANALYSIS (DGA) Monitors gas generation in the transformer for advance notice of developing faults
such as thermal and other electrical faults prior to failure.
FURANIC COMPOUNDS Indicates the degree of degradation of the paper insulation. This is usually done on
transformers aged above 10years.
WATER/MOISTURE CONTENT Measures the moisture content.
DIELECTRIC BREAKDOWN VOLTAGE A low value measurement indicates ingress of contaminates such as water, dirt and
other conducting particles in the oil.
POLYCHLORINATED BIPHENYL ANALYSIS (PCB) Is highly regulated therefore if contamination has been identified, safe handling and
disposal is to be exercised by competent service providers.
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