Truck/Trailer Refrigeration Unit - Sunbelt Transport Refrigeration

g. Minimum On-TimeThe engine is allowed to turn off only after aminimum of four or seven minutes of run time.After the minimum on-time, the unit will go to fullyloaded for setpoints greater than ---12_C(10_F) and highspeed loaded for setpoints of ---12_C (10_F) or less.The unit will not cycle off if the engine coolanttemperature is less than 50_C (122_F) or the battery isless than 13.4 volts. If the unit can not cycle off, it willoperate normally in continuous mode. If all temperatureprobes fail and the setpoint is ---12_C(10_F) or less, theunit will not shut down.The unit will shut down when the box temperature iswithin 0.5_C ofsetpoint.h. Minimum Off-TimeThe unit is designed to select the minimum off-timeof 10, 20, 30, 45 or 90 minutes.After the minimum off-time, the unit will restart fortemperatures beyond 2.0_C(3.6_F) of setpoint for thePerishable range or above +2.0_C (+3.6_F) of setpointfor the Frozen range.i. Battery VoltageProvision is made to sense when the battery is good.A good battery is defined as having 13.4v at 24C_ (75_F).This condition is used to allow shut-off of the dieselengine.If battery voltage falls below 10v during glow cycle,the starter will not engage, and the start sequence willcontinue, it is considered a failed start. The startsequence is repeated until the unit starts or threeconsecutive start attempts have failed.Table1-7.BatteryVoltagesMessage VoltageDisplay LevelDescriptionLOW BATTAL410or LessUnit will shut down exceptduring cranking.11 to 13.4 If the unit has cycled offin auto start/stop modeand battery voltage dropsbelow 11.0 volts, the unitis automatically started tocharge battery. Unit willoperate until a batteryvoltage of 13.4 volts isobtained at which levelunit will stop if temperaturesare satisfied.HI BATTAL517or moreUnit will shut down.j. Oil Pressure SignalWhen the oil pressure switch is closed, it shows thatthe engine is running and prevents engagement of thestarter motor when operating in auto mode.k. Maximum Off-TimeA keypad selectable feature is provided which willcause the engine to be started 30 minutes after the enginehas stopped regardless of the box temperature.1.9 SWITCHES AND CONTROLSMICROPROCESSOR CONTROLLER1.9.1 IntroductionComponents required for monitoring andcontrolling the diesel engine---refrigeration system arelocated in the electrical box. The water temperaturesensor is located on top of the engine.1.9.2 Electrical Box Door (See Figure 1-4)a. Gauges1. Ammeter Gauge (A) --- Trailer UnitTheDCammeterindicatestherateofchargeordischarge of the battery charging system (includingbatteries), battery charging alternator and the voltageregulator.b. Switches1. Run-Stop Switch (RS)When placed in the RUN position, this switchprovides power to the microprocessor.To stop the unit or remove power from themicroprocessor, move the Run-Stop switch to the STOPposition.2. Manual Glow/Crank Switch (MGC)The manual glow/crank switch, when held in theGLOW position, energizes (approximately 7.5 amps perplug at 12 vdc) the glow plugs in the engine to pre-heat thecombustion chamber. The CRANK position of the switchis used to manually engage the engine starter.3. Selector Switch (SSW) --- Trailer UnitThis switch is used to select mode of operation,either engine drive or standby electric motor drive. Whenthis switch is placed in standby position, the electricmotor will not start until the oil pressure safety switch(OP) opens.1.9.3 Location of Engine Safety Devicesa. Oil Pressure Safety Switch (OP)This switch, set to open below 1.0 0.2 kg/cm@ (15 3psig), will automatically stop the engine upon loss of oilpressure. See Figure 1-1 for location.b. Water Temperature Sensor (WTS)This sensor senses engine water temperature. Themicroprocessor will stop the unit when this temperatureexceeds 110 3_C (230 5_F). The sensor is located nearthe thermostat housing in the cylinder head.62-028841-24