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 72 page image

72Fan Status MonitoringGENERAL — The N Series ComfortLink controls offer thecapability to detect a failed supply fan through either a ductstatic pressure transducer or an accessory discrete switch. Thefan status switch is an accessory that allows for the monitoringof a discrete switch, which trips above a differential pressuredrop across the supply fan. But for any unit with an installedduct static pressure sensor, it is possible to measure duct pres-sure rise directly, which removes the need for a differentialswitch.SETTING UP THE SYSTEM — There are two configura-tions of concern located in ConfigurationUNIT. SeeTable 48.Table 48 — Fan Status Monitoring ConfigurationFan Stat Monitoring Type (SFS.M) — This configuration se-lects the type of fan status monitoring to be performed.0 - NONE — No switch or monitoring1 - SWITCH — Use of the fan status switch2 - SP RISE — Monitoring of the supply duct pressure.Fan Fail Shuts Down Unit (SFS.S) — This configurationwill allow whether the unit should shut down on a supply fanstatus fail or simply alert the condition and continue to run.YES — Shut down the unit if supply fan status monitoringfails and send out an alarm.NO — Do not shut down the unit if supply fan status monitor-ing fails but send out an alert.SUPPLY FAN STATUS MONITORING LOGIC — Regard-less of whether the user is monitoring a discrete switch or ismonitoring static pressure, the timings for both techniques arethe same and rely upon the configuration of static pressurecontrol.The configuration which determines static pressure controlis ConfigurationSPSP.CF. If this configuration is set to 0(none), a fan failure condition must wait 60 continuous secondsbefore taking action. If this configuration is 1 (VFD), a fan fail-ure condition must wait 3 continuous minutes before takingaction.If the unit is configured to monitor a fan status switch(SFS.M = 1), and if the supply fan commanded state does notmatch the supply fan status switch for 3 continuous minutes,then a fan status failure has occurred.If the unit is configured for supply duct pressure monitoring(SFS.M = 2), then• If the supply fan is requested ON and the static pressurereading is not greater than 0.2 in. wg for the time clarifiedabove, a fan failure has occurred.• If the supply fan is requested OFF and the static pressurereading is not less than 0.2-in. wg for the time clarifiedabove, a fan failure has occurred.Dirty Filter Switch — This unit is equipped with severalfilter stages. It is important to maintain clean filters to reduce theenergy consumption of the system. This unit is designed to pro-vide several ways to achieve this goal. Table 49 shows the nineconfigurations for filter monitoring in this unit. If the configura-tion for either the main or final filter is set to 0-Disable then theinput is set to read clean all the time. There are several controlswhich need to be used in conjunction with the filter configura-tion so that each corresponding setting will operate correctly.The fault status timer is a parameter which sets the numberof minutes the filter status must be in a fault state before the faultlatch is closed. To set the fault time use ConfigurationIAQFLTCFS.FT the range is between 0 and 10 min-utes. The default for this parameter is 2 minutes.Filter types (MF_TYP, PF_TYP) and final resistance(MF_FR, PF_FR) are used for the Delta Pressure and Predic-tive Life configurations for the main and post filter. The final re-sistance will be automatically set when the filter type is selected.After selecting a filter type it is possible to change the filter finalresistance. Settings for filters based on Table 49 and 50 for mainand post filters.Table 49 — Main Filter TypesTable 50 — Final Filter TypesTo change the filter type for the main filter use Configura-tionIAQFLTCMF.TY set between 0 and 6 according tothe main filter type table. To change the filter type for the finalfilter use ConfigurationIAQFLTCPF.TY set the be-tween 0 and 6 according to the post filter type table. To adjustthe final resistance for the main filter after a filter type has beenselected use ConfigurationIAQFLTCMF.FR and setfrom 0 to 10. To adjust the final resistance for the post filter useConfigurationIAQFLTCPF.FR and set between 0 and10.1 = Switch — If the Filter configuration for either the main orpost filter is set to 1 (Switch) then a filter status switch should beinstalled. The monitoring of the filters is based on a clean/dirtyswitch input.Monitoring of the main and post filter status switches is dis-abled in the Service Test mode and when the supply fan is notcommanded on. If the fan is on and the unit is not in a test modeand either the main or post filter status switch reads "dirty for auser set continuous amount of time, an alert is generated. Re-covery from this alert is done through a clearing of all alarms orafter cleaning the filter and the switch reads clean for 30 sec-onds.ITEM EXPANSION RANGE CCN POINTSFS.S Fan Fail Shuts Down Unit Yes/No SFS_SHUTSFS.M Fan Stat Monitoring Type 0 - 2 SFS_MONMAIN FILTER TYPE(MF_TYP) DESCRIPTION MAIN FILTER FINALRESISTANCE(MF_FR)0 Std 2 in. MERV 11 4 in. MERV 8 12 4 in. MERV 14 1.53 12 in. MERV 14Bag with 2 in. pre’s 24 12 in. MERV 14Bag with 4 in. pre’s 25 19 in. MERV 15Bag with 2 in. pre’s 26 19 in. MERV 15Bag with 4 in. pre’s 27 12 in. MERV 14Cart with 2 in. pre’s 2.58 12 in. MERV 14Cart with 4 in. pre’s 2.59 Strion Air 2MAIN FILTER TYPE(MF_TYP) DESCRIPTION MAIN FILTER FINALRESISTANCE(MF_FR)0 None 01 12 in. MERV 14Cart with 2 in. pre’s 2.52 12 in. MERV 14Cart with 4 in. pre’s 2.53 19 in. MERV 15Bag with 2 in. pre’s 24 19 in. MERV 15Bag with 4 in. pre’s 25 12 in. MERV 17Bag with 2 in. pre’s 36 12 in. MERV 17Bag with 4 in. pre’s 3