York SUNLINE 2000 D2CG 072 Installation Instructions Manual

Contents

York SUNLINE 2000 D2CG 072 Installation Instructions Manual Manual pdf 16 page image

The limit switch operates when a high temperaturecondition, caused by inadequate supply air flow, occursshutting down the ignition control and closing the main gasvalve.2. Centrifugal Switch (CS-36). If the draft motor should fail, thecentrifugal switch attached to the shaft of the motorprevents the ignition control and gas valve from beingenergized.3. Redundant Gas Valve. This valve is an integral part of themain gas valve and is located up stream of the main gasvalve. Should the main gas valve fail in the open positionthe redundant valve serves as a back up and shuts off theflow of gas.4. Flame Sensor Rod. This sensor rod is located on the farside of the carryover tube. If the ignition control does notreceive a signal from the flame sensor indicating that thepilot flame has ignited properly, the main gas valve will notopen. If the flame sensor fails to detect the pilot flame duringoperation of the main burners, a signal is sent to the ignitioncontrol to close the main gas valve.5. Rollout Switch. This switch is located in the burnervestibule. In the event of a sustained main burner flamerollout, it shuts off the ignition control and closes the maingas valve.6. Auxiliary Limit Switch. This control is located inside the heatexchanger compartment and is set to open at 180°F. It is amanual reset switch. If the auxiliary limit switch trips, thenthe primary limit switch has not functioned properly.Replace the primary limit switch.HEAT ANTICIPATOR SETPOINTSThe anticipator must be set correctly. Too high of a setting willresult in longer heat cycles and a greater temperature swing inthe conditioned space.Reducing the value below the correct setpoint will give shorter“ON” cycles and may result in the lowering of the temperaturewithin the conditioned space.PRE-START CHECK LISTComplete the following checks before starting the unit.1. Check the type of gas being supplied. Be sure that it is thesame as listed on the unit nameplate.2. Make sure that the vent and combustion air hoods havebeen properly installed.Units(Tons)Capacity, MBH Limit ControlOpens, °FInput Output3434556650751001251001251001254060799979997999165165165165165165165165TABLE 16 - LIMIT CONTROL SETTINGGas Valve Anticipator SetpointHoneywell VR8204M 0.60 ampWhite-Rodgers 36E36 0.54 ampSTART-UPOPERATING INSTRUCTIONSCAUTION: This furnace is equipped with an intermittent pilotand automatic re-ignition system. DO NOT attemptto manually light the pilot.TO LIGHT PILOT AND MAIN BURNERS:1. Turn “off” electric power to unit.2. Turn room thermostat to lowest setting.3. Turn gas valve knob to “on” position.4. Turn “on” electric power to unit.5. Set room thermostat to desired temperature.(If thermostat “set” temperature is above room temperature,pilot burner ignition will occur and, after an interval to provepilot flame, main burners will ignite).TO SHUT DOWN:1. Turn “off” electric power to unit.2. Depress knob of gas valve while turning to “off” position.POST-START CHECK LIST (GAS)After the entire control circuit has been energized and theheating section is operating, make the following checks:1. Check for gas leaks in the unit piping as well as the supply piping.2. Check for correct manifold gas pressures. See “CheckingGas Input”.3. Check the supply gas pressure. It must be within the limitsshown on rating nameplate. Supply pressure should bechecked with all gas appliances in the building at full fire.At no time should the standby gas line pressure exceed 13",nor the operating pressure drop below 4.5" for natural gasunits. If gas pressure is outside these limits, contact thelocal gas utility for corrective action.MANIFOLD GAS PRESSURE ADJUSTMENTSmall adjustments to the high-fire gas flow may be made byturning the pressure regulator adjusting screw on the automaticgas valve. Refer to Figure 11.Adjust as follows:1. Remove the cap on the regulator. (High Fire adjustingscrew on valve).2. To decrease the gas pressure, turn the adjusting screwcounterclockwise.3. To increase the gas pressure, turn the adjusting screwclockwise.NOTE: Check the unit data plate for the proper manifold pres-sure and orfice size of the furnace.PILOT ADJ.(UNDERSCREW)“ON”-"OFF"CONTROLHIGH FIRE ADJ.(UNDER SCREW)HoneywellVR8204M “ON”-"OFF" CONTROLPRESSURE REGULATORMANIFOLD ADJUST. SCREW 1/2-14 NPT (OUTLET)White-Rodgers36E36PILOT ADJ.(UNDERSCREW)FIG. 11 - GAS VALVES530.18-N8Y16 Unitary Products Group