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equipped with a brake or backstop device. A mechanically-applied electrically released brake
should be generated to the motor shaft for direct connected units or to the input shaft for
belt-driven units. The brake should be capable of stopping and holding the inclined conveyor
when the weighted side is loaded with materials. Observe the brake operation to make certain it
applies when the conveyor is stopped, and electrically releases it when the unit is started.
15.2.9 Controls
The following inspection procedure applies to all the control mechanisms, including starting
panels for the manlift drive motor. A good preventive maintenance program on the control
equipment will greatly reduce shutdowns.
15.2.9.1 Inspection Made with Power Off. Remember that the conveyor you are inspecting may
be for a series of devices controlled by more than one mainline switch. Caution must be used to
know which, if any, devices are still active when making this area of the inspection. Open the
mainline switch and examine all relays, switches, contactors, control circuit rectifiers,
transformers, capacitors, reactors, etc. Check for any excessively worn or burned contact broken
connectors, broken or cracked resistance grids or resistance tubes. Any fuses that are shorted
with wire, solder or metal strips must be replaced. Examine to see that the equipment is clean.
Any accumulation of combustible materials, especially on resistance grids or wires or on control
circuit rectifiers, is a common cause of fire. Check whether contacts of reverse-phase relay,
where provided, are open. Also be sure to check for excessively worn pin hinges on relays or
contactors.
15.2.9.2 Inspections Made with Power On. Close the mainline switch and proceed to observe
the operation of the control equipment when the conveyor is running. Note any arching of
contacts, excessive hearing of coils or resistances, and misalignment of relays, contactors, and
switches. Unusual noises should also be noted.
15.2.10 Machinery Areas
15.2.10.1 Illumination. Check the machinery areas and walkways for adequate lighting.
15.2.10.2 Housekeeping. Check the machinery area for housekeeping and the presence of any
flammable liquids (flash point less than 110 degrees F) or materials not necessary for the
operation and maintenance of the conveyor.
15.2.10.3 Ventilation. Check the machinery area to see that adequate ventilation by natural or
mechanical means has been provided to ensure safe and normal operation. Check local codes to
see that machine ventilation is in compliance.
15.2.10.4 Fire Extinguisher. Check the machinery areas for fire extinguisher, proper glass,
15-5








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