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16 Cards in this Set
- Front
- Back
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List 3 kinds of pressure found in operating fan ducts |
Static pressure Velocity pressure Total pressure |
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What is a manometer used for |
U shaped tube that is connected to the fan for measuring pressures |
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How can you remove static electricity generated by fans |
Ground the rotating element with a ground brush and cable assembly |
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Name the two major types of fans according to flow through the impeller |
Radial flow centrifugal Axial flow propeller |
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What is the name of the circular collection chamber mounted around the fan wheel of a centrifugal fan |
Stationary scroll |
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Name two ways of placing bearings on a shaft in relationship to the fan wheel |
The wheel can be mounted between the bearing The wheel can be mounted overhung on the shaft |
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How can control of air through the fans be accomplished |
Inlet louvres, vary speed, outlet dampers |
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Why are some fans mounted on a base with the aid of springs |
Absorbs vibration, allows for large thermal movements |
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What is the plan called that allows periodic checking of fans on a routine basis |
Preventative maintenance |
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Troubleshooting of fans is best accomplished by using which type of monitors |
Online vibration monitors |
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Fan overhaul is best accomplished by following what directions/instructions |
Manufacturers manual |
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Why should all parts be inspected and measured during an overhaul |
All parts need to be inspected for off-specification sizes and fatigue (cracks) |
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Why would the fan wheel hub be heated before installing it on a shaft |
The bore size is increased with heat, allowing easy installation onto a cold shaft |
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Explain the purpose of balancing a fan rotor in a dynamic balancer |
Dynamic balancing is performed to reduce the vibration of the fan to acceptable levels |
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What is the purpose of a cold rollover of the fan rotor |
A cold rollover is used to confirm that there are no rubbing metal parts and no cracking noises experienced after a fan is overhauled |
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