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 13.2.5.1 Inspection Made with Power Off. Open the mainline switch and examine all relays,
switches, contactors, control circuit rectifiers, transformers capacitors, etc. Check for excessively
worn or burned contacts, broken connectors, broken or cracked resistance grids or resistance
tubes. Any fuses that are shorted with wire, solder or metal strips must be replaced. Check
whether contacts of reverse-phase relay, where provided, are open. Examine to see that it is
clean. Any accumulation of combustible materials, especially on resistance grids or wires or on
control circuit rectifiers, is a common cause of fire. Also, look for excessively worn pin hinges
on relays or contactors.
13.2.5.2 Inspections Made with Power On. Close the mainline switch and proceed to observe
the operation of the control equipment when the roof car and power scaffold are running. Note
any arcing of contacts, excessive heating of coils or resistances, and misalignment of relays,
contactors, and switches. Roof car and power scaffold speed must also be checked and compared
with previous test data and criteria. The speed is checked with a hand held tachometer with its
drive wheel directly engaging the roof track or parapet (roof car) and the building face (powered
scaffold). Unusual noises should also be noted.
13-10
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