ECONET PREMIUM TROUBLE-SHOOTING: Start by checking all indata for the air handling unit.
2 Air temperatures/humidity Outdoor air temperature C Thermometer or AHU/Econet Supply air temperature C Thermometer or AHU/Econet GT 20 Extract air temperature C Thermometer or AHU/Econet Extract air humidity % Econet GT 21 Exhaust air temperature C Thermometer or AHU/Econet Liquid temperatures Supply coil, in C Thermometer or AHU/Econet Supply coil, out C Thermometer or AHU/Econet Extract coil, out C Thermometer or AHU/Econet Cooling, in C Thermometer or AHU Heating, in C Thermometer or AHU Flows Supply air flow m 3 /s Econet Supply air flow m 3 /s AHU FO 10 Supply fr. inverter Hz Frequency inverter Exhaust air flow m 3 /s AHU FO 21 Exhaust fr. inverter Hz Frequency inverter Liquid flow l/s Econet FO 40 Liquid fr. inverter Hz Frequency inverter Functions HRS Heat recovery signal % AHU or Econet controls Exhaust by-pass value pos. % Econet controls Supply by-pass value pos. % Econet controls Temp. efficiency, supply, real Temp. efficiency, supply Temp. efficiency, exhaust
3 ICE ALARM, : Low liquid temperature (GT42). Risk of destoying the heat/cooling exchangers. Default alarm set point: R : +2 C Heat recovery signal: R Check that heat recovery signal is 100% (10V) from BMS Ice alarm By pass valve : R Position If closed and out door air > -20 C and low humidity in extract air. If partly open (0-50%) <-20 C and high humidity in extract air. If 100 % open. -> not ok Heat recovery signal 0-30% Error in valve or cabling Cooling sequence Error in valve or cabling Manual position of valve. GF10,20: Air flow: R Exhaust air, GF20 << supply air, GF10 R Exhaust air, GF20 << of dimensioned Exhaust/Extract Air coils: R Frost formation on the exhaust air coil GT20: Extract air temperature: R Extract air temperature, GT20 << of dimensioned GP41: Liquid flow: R Liquid flow > 1/3 of supply air flow. R Otherwise, ECONET does not increase the liquid flow although state frost protection. Check the parameters Check air and liquid flow sensors Check the frequency inverter, shall be in automatic position. When state not running: R When continuous Ice alarm the supplementary heating valve has to open during state not running, set value for opening SV30 (heating valve) for example GT42= +10 C, look at Econet functional description. When state, start up: R Start sequense for AHU, first start ECONET and exhaust air unit, after 2-4 minutes start supply air unit.
4 FROST ALARM, : Low liquid temperature (GT41). Risk of frost formation in the exhaust air coil (air). Default alarm set point: R : -10 C Heat recovery signal: R Check that heat recovery signal is 100 % (10V) from BMS Frost alarm GP41: Liquid flow: R Liquid flow > 1/3 of supply air flow R GT40 > GT10 + 4 C R Otherwise, ECONET does not increase the liquid flow although state frost protection Check the parameters Check air and liquid flow sensors Check the frequency inverter, shall be in automatic position. GT10: Supply air temperature: R Actual temp. <-> to set value R Actual temp. << set value Too low temp. at primary heating in (SV 30) Too low liquid flow for primary heating Too low recovered energy from exhaust air. GT00: Out door air temperature: R GT00 << than dimensioning winter out door air temperature When state, start up: R Start sequence for AHU, first start ECONET and exhaust air unit, after 2-4 minutes start supply air unit * = The output groups up to and including 3.5 kw should be connected for 2-phase, 400 V/440 V
5 PRESSURE ALARM GP40: Under pressure alarm for protecting the pump and system leakage. Default alarm set point: R 0,5 bar Air purged: R Fill up the system to a 1-2 bar static pressure Leakage: R Find the leakage and fix it Under pressure alarm GP40 Air in the liquid circuit: R Check air purging equipment R Purge the air Fill up the system to a 1-2 bar static pressure. Component failure GP40: R Check
6 HEAT RECOVERY EFFICIENCY: If low temperature efficiency then analyse acording to The temperature heat recovery efficiency is calculated as: η = (GT42-GT41) x (GT10-GT00) (GT40-GT41) x (GT20-GT00 When the heating valve SV30 is open. η = (GT10-GT00) (GT20-GT00) When the heating valve SV30 is closed. η = (GT21-GT20) (GT00-GT20) When cooling recovery is calculated. Heat recovery signal: R Check that heat recovery signal is 100% (10V) from BMS GF10, 20: Air flow: R Supply air flow = exhaust air flow R Supply air flow > exhaust air flow R Supply air flow < exhaust air flow lower efficiency higher efficiency GT21: Exhaust air temperature: R GT21 < GT41 +6 R GT21~GT00 Exhaust air flow lower than the supply air flow R GT21~GT20 SV40 open Exhaust air flow bigger than the supply air flow GT20: Extract air temperature: R Check that the extract air temperature/humidity is similar to dimensioned R Lower efficiency if: Lower exhaust air temperature Lower exhaust air humidity R Higher efficiency if: Higher exhaust air temperature Higher exhaust air humidity
7 HEAT RECOVERY EFFICIENCY: If low temperature efficiency then analyse acording to GT00: Out door air temperature: R -10 C < GT00 < 0 R GT00<-10 C Reduced heat recovery due to frost formation mode. R GT00>+10 C Most likely reduced heat recovery due to reduced need. GT10: Supply air temperature: R Check that the supply air temperature is similar to dimensioned. GP41: Liquid flow: R Shall be 1/3 of the air flow l/s vs. m 3 /s R < 1/3 of the supply air flow Reduced heat recovery (Heat rec. signal < 100%) R ECONET gets wrong air flow Parameter fault R Liquid flow > 1/3 of the supply air flow Ice/frost formation mode GT40: Liquid temperature: R GT40~GT10 +6 C R GT40~GT41 High liquid flow Low supply air flow R GT40 > > GT10 GT41: Liquid temperature: R GT41~GT00 +6 C R GT41~GT40 High liquid flow Low supply air flow Low liquid flow R GT41~GT00 Low liquid flow Low supply air flow R GT41 < -3 C Frost formation mode with high liquid flow