(c)“Water Temperature” light will come on and engine will stop.
(d)Turn Mode Selector switch OFF.
4-4.9Low Water Temperature; to test the low water temperature alarm circuit:
(a)Engine does not have to be running.
(b)Use a jumper wire and short from terminal 31 to 4.
(c)“Low Water Temperature” alarm light will come on as long as the jumper maintains the circuit.
4-4.10Other Alarm and/or Shutdowns; all other alarms and shutdowns would be tested in the same manner.
(a)For shutdown circuits, the engine must be running for test.
(b)Most alarm only circuits can be tested without starting the engine. Low Oil Pressure Pre-alarm and High Water Temperature Pre-alarm are exceptions.
(c)To test other shutdowns or alarms, a jumper wire can be used to short out the switch contacts at the switch or if this is not possible, the test can be run by shorting the input terminal for that circuit, to ground, terminal 4.
(d)To test Low Oil Pressure Pre-alarm;
1.Turn Mode Selector switch to TEST. When engine starts, wait 30 seconds then,
2.Use a jumper wire and short from terminal 50 to 4; “Low Oil Pressure Pre-alarm” light will come on as long as the jumper maintains the circuit.
(e)To test High Water Temperature Pre-alarm;
1.Turn Mode Selector switch to TEST. When engine starts, wait 30 seconds then,
2.Use a jumper wire and short from terminal 51 to 4; “High Water Temperature Pre-alarm” light will come on as long as the jumper maintains the circuit.
Section 5: Operation
5-1 Operator Controls.
5-1.1Mode Selector Switch; allows the operator to select either manual (TEST), automatic operation (AUTO), or no operation (OFF).
5-1.2The OFF position on the mode selector also provides a reset function for the shutdown circuits. If the engine is shut down by the automatic control, the operator must turn selector off and back on to reactivate the system.
5-1.3Push to Test Lamps; this pushbutton tests the alarm and shutdown indicator lights.
5-1.4Alarm Silence Pushbutton; if so equipped, silences the local and remote audible alarm. Visual indicator remains on until reset or sensor switch contacts clear.
5-2 Operating Modes.
5-2.1The A900 Generator Engine Control has two operating modes: manual and automatic.
5-2.2Manual Operation is provided for testing of the generator set.
5-2.2.1To initiate Manual Control, place the Mode Selector switch in the TEST position. This provides the automatic control a start signal.
5-2.2.2To stop, turn selector switch to OFF. This removes start signal and the engine will stop.
5-2.3Automatic operation is the normal mode.
5-2.3.1To initiate Automatic Control, place the Mode Selector switch in the AUTOMATIC position. When a start signal is
received, the engine will start.
5-2.3.2When the start signal is removed, the engine will stop. It is now ready to restart.
5-2.4OFF or Not Operating; to prevent operation of the engine, turn selector switch OFF.
Section 6: Routine Maintenance and Operational Tests
6-1 Routine Maintenance.
6-1.1Due to the design and types of components used, very little maintenance is required to the A900 Control.
6-1.2Visual inspection of the internal wiring of the control panel, along with checking wire connections for tightness, should be done on a semiannual schedule for stand-by systems or quarterly for prime power. Check wire bundles for chafing and wear to the insulation of the wires where they contact the panel or engine.
6-1.4Shutdown and Alarm Circuits should be tested on a monthly basis for prime power and quarterly for stand-by sets. The same tests run during pre-operation check out, Section 4-4, should be included.
6-2 Operational Tests.
6-2.1No special operational tests are required. The routine operational tests for the generator set will exercise the control.
Section 7: Troubleshooting and Repair
7-1 Tools Required.
7-1.1Some of the tools necessary for troubleshooting are built into the A900 Series controls.
7-1.1.1By observing the lights on the front and rear of the control panel, clues to a problem and the possible source can be seen.
7-1.1.2Operational problems with the automatic engine control will show up by looking at the input and output lights on the rear of the A900 SELECTRONIC® Control / Display Module.
7-1.2Other tools which may be required are:
7-1.2.lAC/DC Voltmeter for taking voltage readings and an Ohmmeter for testing resistance of wires and connections.
7-1.2.2Jumper wires with alligator clips to bypass or simulate circuit closures.
DO NOT USE THESE JUMPER WIRES TO CHECK IF VOLTAGE IS PRESENT AT A TERMINAL BY DRAWING AN ARC TO GROUND. THIS WILL DAMAGE OR DESTROY EQUIPMENT IN THE A900 CONTROL PANEL.
7-2 A900 SELECTRONIC Control Operation And Shutdown.
7-2.1The first step in troubleshooting any equipment is to understand its normal operation. Table 7-2.1 contains normal voltage readings taken at the terminals of the A901 with all equipment shown on the standard drawing, connected.
(a)All voltage readings are DC, except at terminal 29, and were taken with the negative lead of the meter connected to ground at terminal 4. Voltage reading at terminal 29 was taken with negative lead grounded and the meter on AC scale.
(b)The battery voltage, at the time readings were recorded, was 13.8 V and 27.6 V. All readings will vary depending on battery voltage, equipment supplied in the panel and external devices connected to the A900 control. See notes
