Hydraulic Control Panel Flashcards
1
Q
SYSTEM HYDRAULIC PUMP LOW PRESSURE lights
A
- indicates low pump output pressure from ENG 1 or ELEC 2 pump
- ENG LOW PRESSURE lights inhibited with fire handle pulled
fluid flow to the associated engine driven pump is shut off
2
Q
ENGINE DRIVEN PUMP switches
A
ON
- the depressurization solenoid valve is not energized; this allows pump pressure to enter the hydraulic system
- normally keep this switch in the ON position to prolong solenoid life
- loss of normal electrical power to the control circuit does not affect the output of the pumps
OFF
- energizes the depressurization valve to block pump output
- re-routes hydraulic fluid to the case drain line and back to the reservoir
- this does not stop the rotation of the pump or the internal pressure in the pump
- the pump continues to be lubricated
- not so if you pull the fire handle which closes the EDP supply SOV to block fluid flow to the pump - there is no case drain fluid in this condition
3
Q
ELECTRIC MOTOR PUMP switches
A
ON
- provides electrical power to corresponding electric motor driven pump
4
Q
Electric Driven Motor Pump Overheat lights
A
- hydraulic fluid is used to cool and lubricate the corresponding EMDP
- a temperature switch in the case drain line downstream of the pump monitors the EMDP case drain fluid for overheat
- the OVERHEAT light illuminates when the case drain fluid temp increases to more than normal (> 225F)
- there is also a temperature switch in the EMDP motor that will cause the OVERHEAT light to illuminate if the motor reaches a temperature more than normal