Foxboro Controls Flashcards
- On a typical Motor Start Stop (MSS) station what does NAC mean? What does NAT mean?
NAC- Normal After Closed
NAT- Normal After Trip
- What does sliding pressure mean? Constant pressure?
Sliding- will automatically ramp up or down as load goes up or down. Range is 1800-2400 psig. Constant- maintained to setpoint, not dependent load.
- In full boiler master auto, what are the two ways an operator can change throttle pressure?
By manually entering set point or by depressing the arrows
- On the boiler master % output bar, what does it mean if the yellow bar is ahead of the two green bars?
Demand is higher than actual pressure.
- What mode are you in with fuel and air in auto, boiler master and turbine master in auto?
Operator auto
- What mode are you in if only turbine master is in manual and boiler master and fuel-air is in auto?
Boiler follow
- What mode are you in if boiler master is in manual and turbine master and fuel-air is auto?
Turbine follow
- Explain what you would do if one of the throttle pressure transmitters failed.
Bring up pressure transmitter overlay from boiler master page
Compare transmitter readings with actual pressure
Select proper transmitter and select override
Place boiler master back in auto
Write work order for bad transmitter
- What are the two ways to change the furnace draft set point on the furnace draft master?
By manually entering set point or by depressing the arrows
- When can the ID fans be put in auto?
- ID Fan is running and proven
- Shut off damper is open and in auto
- Furnace pressure has been met to set point
- When can the FD fans be put in auto?
. FD Fan is running and proven
- Shut off damper is open and in auto
- Associated ID fan is running and proven
- When can the FD fan Master be put in auto?
Once 1 ID & 1 FD fan is in auto
- What does it mean if the bottom green bar on the FD fan Master % output bar is ahead of the top green bar? What does the yellow bar indicate?
The green bars indicate the percentage of output of each FD fan. (East and West). If the bottom green bar is ahead of the top green bar, the fans are biased higher to the east. The yellow bar indicates the demand of the fans.
- How do you start a boiler purge on the Boiler Status Master?
No trips on boiler No flame detected Aux air dampers modulating All mills off All gas valves tripped Air flow greater than 25% Fans on (Purge will automatically start when all permissives are met and will time out in 5 minutes.)
- When can the Igniter Trip Valve be closed? The Gas Trip Valve?
Igniter trip valve – once all igniters have been taken out
Gas trip valve – once all elevations of main gas are taken out