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9 Cards in this Set
- Front
- Back
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Interlocks |
Making the position or motion of any part dependent upon the position or motion of another part |
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Permissive Interlocks Tripping Interlocks |
Types of Interlocks |
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Permissive Interlocks |
Grant permission for the operator to do something providing the person has complete the preceding step |
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Tripping Interlocks |
Trip or shut down equipment in the event some limit is reached or some part fails to do its job |
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Thermostat on a heating system |
Example of Tripping Interlock |
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1. Induced draft fan on 2. Forced draft fan on 3. Time delay 4. Adequate boiler water circulating pump d.p 5. Ignitors on 6. Admission of main fuel |
Sequence of Operation for Boiler Starting |
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Excessive high or low Furnace Pressure (IDF, FDF, Ignition gas, main fuel)
All Induced Draft Fan (FDF, Ignition Gas, Main Fuel)
All Forced Draft Fans (IDF, Ignition Gas, Main Fuel)
Ignition Gas high or low pressure and excess flow (Ignition Gas Supply)
Exhauster
Pulverizer
Loss of Coal between feeder and bunker on some pressurized boilers
Ignition detectors for ignitors only |
Equipments interlocked so it trips under Tripping Boiler Interlocks |
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Both forced draft fans and/or induced draft fan off High water level in low pressure heaters Control valves in no load position Low pressure turbine vibration trip Low oil pressure to beatings Turbine exhaust, low vacuum trip Turbine overspeed trip speed Turbine auto stop oil pressure low |
List of Tripping interlocks associated with the turbine that must he cleared latching up the turbine |
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Turbine auto stop oil pressure Generator loss field Generator neutral over voltage Generator differential relays Transformer sudden pressure relay Transformer Differential Transformer Ground |
List of tripping interlocks associated with electrical generator and transformers |
