Table 4-5.A/M27T-5 Main Control Panel Controls and Indicators-Continued
Panel Light (DS3)
Provides main control panel lighting. Illuminates if
ignition switch S1 is set to IGNITION ON.
PRESSURE BYPASS VALVE
When open, causes HIGH PRESSURE RELIEF
VALVE to dump flow to return line at no pressure.
HIGH PRESS FILTER indicator
Illuminates when high pressure filter high
differential pressure switch S2 closes. S2 will close
if high pressure filter inlet and outlet pressures
differ by 100 psi or more.
H.P. GAUGE TEST port
Allows application of hydraulic fluid from external
source for use in testing and calibrating HIGH
PRESSURE GAUGE. Used only when H.P.
GAUGE SHUTOFF VALVE (on secondary control
panel) is closed.
High pressure gauge calibrating
Used to calibrate HIGH PRESSURE GAUGE when
H.P. SHUTOFF valve (on secondary control panel)
HIGH PRESSURE GAUGE
Indicates hydraulic pressure (0 to 6000 psi scale) at
PRESSURE OUTLET ports. closing H.P. GAUGE
SHUTOFF valve (on secondary control panel)
isolates HIGH PRESSURE GAUGE from hydraulic
system, enabling testing and calibration of gauge.
Indicates hydraulic fluid temperature (20° to 220°F
scale) at hydraulic pump high pressure inlet port.
Ignition switch S1
When set to IGNITION ON turns on panel lights
DS1, DS2, and DS3 and IGNITION ON indicator
DS9. Switches battery current to power supply
electrical system, enabling diesel engine start-up.
IGNITION ON indicator (DS9)
When illuminated, indicates ignition switch S1 is
set to IGNITION ON.
HEAD TEMPERATURE gauge
Indicates diesel engine coolant temperature (100° to