Harris Atlas DVL400, Technical Manual

Page: 135 / 180

2/25/03 888-2473-001 4-35
WARNING: Disconnect primary power prior to servicing.
Section 4 Theory of Operation
ATLAS Series™
4.5.4.4 AC Line Monitoring
The PS Monitor board monitors the condition of the incoming 1 or 3 phase AC lines
and provides status updates to the main controller via the CAN network. Upon
detecting certain conditions, the power supply monitor can activate the /FLT_OFF,
/RF_MUTE, /PS_MUTE, or /AC_LOW command based on the fault. The
following AC line conditions are monitored:
•
AC line voltage
•
Phase imbalance
•
Phase sequence (rotation)
The MOV board supplies a scaled ac current sample of each of the phases to the PS
Monitor board. The phase samples are an ac rms value such that 400VAC rms
primary = 16.7milliamps ac rms. This ac rms signal is averaged to generate a scaled
dc representation for metering and protection. Table 4-3 on page 4-37, shows the
analogue metering sample levels and scaling factors used for the metering display.
The MOV board also provides four discrete lines to the PS Monitor Board to
indicate when a fuse is open on the MOV board.
4.5.4.5 Cabinet Cooling System Sensors
The PS Monitor connects to five sensors which are monitoring the cabinet cooling
system.
•
Ambient Temperature (Control Enclosure)
•
Air Pressure
•
Coolant Temperature
•
Coolant Flow
•
Coolant Leak
Four of the sensors are located off the board with the ambient air temperature sensor
physically mounted on the PS Monitor Board. Sensor levels and the scaling used for
the display metering are shown in Table 4-3.
4.5.4.5.1 Ambient Temperature
A temperature sensor is installed on the Power Supply Monitor board that monitors
the ambient temperature of the transmitter control enclosure. The sensor outputs a
voltage that is directly proportional to the temperature in degrees Celsius. The
micro-controller will monitor this reading and report it to the main controller.