Civil Engineering Reference
In-Depth Information
Once the electrical systems are documented, obtain minimum test
instruments, as listed below. Without test instruments, it is impossible to
determine what is actually happening in each electrical system. Without
this information, repair or additional maintenance requirements cannot
be identified.
Table 3-2. Minimum Required HVAC Maintenance Instruments
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QuantitytobeEvaluated
Instrument(s)Required
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High voltage occurrence Statiscope
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Volts, amps, ohms Volt meter, volt-ohmmeter, and clamp-on
(instantaneous) ammeter with multiscale ranges
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Volts, amps, ohms, watts,
Recording instruments
power factor, or volt-
amperes (over a period
of time)
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Circuiting Continuity tester
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Receptacle circuiting Receptacle circuit tester
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Insulation resistance Megohmmeter
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Ground fault Ground fault locator
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The most common cause of electrical equipment failure is loose con-
nections. Every electrical maintenance program must include routine in-
frared imaging testing and required tightening of electrical connections.
Therefore, insulated tools, gloves, and other protection must be available
so that this effort can be done safely while equipment is energized.
For larger systems, an initial short-circuit and coordination study
should be performed by a professional engineer to serve as a resource for
the maintenance staff is selecting fuse sizes and adjusting over-current
protection devices.
Allelectricalsystemsmaintenancepersonnelmusthaveaworkingknowl-
edgeofNFPA70,NationalElectricalCode;NFPA70B,RecommendedPractice
forElectricalEquipmentMaintenance;andNFPA70E,StandardforElectrical
SafetyintheWorkplace.
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