Truck/Trailer Refrigeration Unit - Sunbelt Transport Refrigeration

1.8.9 AUTO START/STOP OPERATIONAutomatic start/stop is provided to permitstarting/restarting of the diesel-driven compressor asrequired. This feature fully enables automatic control of thediesel engine starting and stopping. The main function ofautomatic engine cycling is to turn off the refrigerationsystem near setpoint to provide a fuel efficient temperaturecontrol system and to initiate a restart sequence afterconditions are met. System shut-off is allowed only if thebattery condition signal is good. The engine coolanttemperature shall override the minimum off time andout-of-range condition to force engine restart when theengine coolant temperature drops below 1_C (34_F). Arestart will also be initiated if the battery voltage falls below11.0 Vdc.a. Autostart/Stop -- ContinuousA key is provided to select between continuous runand auto start/stop operating mode. In the continuousrun mode, the diesel engine will not shut down except forsafeties or if the engine stalls. This function also apply tothe operation of the electric motor.b. Auto Mode IndicatorThe “Auto start/stop” indicator is lit and will be on toindicate the autostart/stop mode has been selected.c. Auto Start FailureIf the unit, for three consecutive times: fails to start,shutsdownonasafety,orfailstorunfortheminimumrun time, the “Start/Fail” alarm is activated.d. Continuous Run ModeIn continuous run mode, the engine is started but notallowed to shut off except for safeties or if the engine stalls.e. Auto Start SequenceWhen the starting conditions are met, the startsequence will begin by energizing the run relay, and afterfive seconds energize the glow plug relay (GPR) to supplypower to the glow plugs, and five seconds later the starteris energized. On initial power-up, the control will delayfive seconds before the starting sequence begins. If therequired glow time is zero, the control will energize thestarter after a five second delay. After a period of time ,the starter solenoid (SS) is energized to crank the engine.The engine will crank for 10 seconds or until engineoperation is sensed by the alternator signal. The glowrelay is de-energized after the auxiliary input is sensedon. A 15 second null cycle will elapse before subsequentstart attempts. The run relay will remain energized untilthe next starting sequence.Before the next starting sequence, the oil pressurealternator auxiliary output is checked to insure that theengine is not running. For the second and third startattempts, the glow time is increased by five seconds over theglow time of the first attempt listed below. The controlallows three consecutive start attempts before the starting islocked out and the start failure alarm is activated.REPEAT “A”+ 5 SecondsGLOW15 SecondsSTOPREPEAT “A”+ 5 SecondsGLOW15 SecondsSTOPMAXIMUM10 SecondsChecked at2 SecondsVARIABLE0to30SE-CONDSGLOWCRANKGLOWTHIRDAT-TEMPTSECONDAT-TEMPTFIRSTATTEMPT“A”Figure 1-14. Auto Start Sequencef. Variable Glow TimeThe glow time for the first start attempt will vary induration based on engine coolant temperature and theunit type as follows:Glow Time inAmbient TemperatureSecondsTruck TrailerLess than 0_C (32_F) 55 151_C to10_C (33_F to50_F) 40 1011_C to25_C (51_F to77_F) 25 5Greater than 26_C (78_F) 10 0The second and third start attempts have a glow timethat is five seconds greater than the table amount. Theglow time can be manually overridden through thefunction parameters. If the coolant temperature sensor isdefective the control assumes a temperature of less than0_C (32_F) for the glow timing.1-23 62-02884