Carrier WeatherExpert 48N2 Controls, Start-up, Operation, Service And Troubleshooting Instructions

Also see for WeatherExpert 48N2: Installation instructions Installation instructions Controls, start-up, operation, service, and troubleshooting Installation instructions

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Carrier WeatherExpert 48N2 Controls, Start-up, Operation, Service And Troubleshooting Instructions Manual pdf 6 page image

6Accessory Installation — Check to make sure that allaccessories including space thermostats and sensors have beeninstalled and wired as required by the instructions and unit wir-ing diagrams.Crankcase Heaters — Crankcase heaters are energizedas long as there is power to the unit, except when the compres-sors are running.Evaporator Fan — Fan belts and fixed pulleys are facto-ry-installed. See Tables 3-18 for fan performance. Be sure thatfans rotate in the proper direction. Component pressure dropdata is shown in Tables 19 and 20. See Tables 21 and 22 for mo-tor limitations.FIELD-SUPPLIED FAN DRIVES — Supply fan and powerexhaust fan drives are fixed-pitch, non-adjustable selections, formaximum reliability and long belt life. If the factory drive setsmust be changed to obtain other fan speeds, consult the nearestBrowning Manufacturing Co. sales office with the required newwheel speed and the data from Physical Data and Supply FanDrive Data tables (center distances, motor and fan shaft diame-ters, motor horsepower) in Installation Instructions for a modi-fied drive set selection. For minor speed changes, the VFD canbe used to provide speed control. See page 157 for belt installa-tion procedure.Controls — Use the following steps for the controls:1. Set any control configurations that are required (field-installed accessories, etc.). The unit is factory configuredfor all appropriate factory-installed options.2. Enter unit set points. The unit is shipped with the set pointdefault values. If a different set point is required, use theNavigator™ display, or CCN interface to change the con-figuration values.3. If the internal time schedules are going to be used, config-ure the Occupancy schedule.4. Verify that the control time periods programmed meetcurrent requirements.5. Use Auto Commisioning mode to verify operation of allmajor components.6. If the unit is a VAV unit make sure to configure the staticpressure set point. To check out the VFD, use the VFD in-structions shipped with the unit.Gas Heat — Verify gas pressure before turning on gas heatas follows:1. Turn off field-supplied manual gas stop, located externalto the unit.2. Connect pressure gages to supply gas tap, located at field-supplied manual shutoff valves.3. Connect pressure gages to manifold pressure tap on unitgas valve.4. Supply gas pressure must not exceed 13.5 in. wg. Checkpressure at field-supplied shut-off valve.5. Turn on manual gas stop and initiate a heating demand.Jumper R to W1 and R to W2 in the control box to initiatehigh fire heat.6. After the unit has run with high fire energized for severalminutes, verify that incoming pressure is 5.0 in. wg orgreater and that the manifold pressure is 3.1 in wg. Ifmanifold pressure must be adjusted refer to Gas ValveAdjustment section on page 171.7. Use the Service Test procedure to verify all heat stages ofoperation.IMPORTANT: Unit power must be on for 24 hoursprior to start-up of compressors. Otherwise damage tocompressors may result.IMPORTANT: The unit is shipped with the unit controldisabled. To enable the control, set Local Machine Disable(Service TestSTOP) to No.