Carrier 50FF Series Control Manual

Also see for 50FC Series: Installation, operation and maintenance instructions Controls, Start-Up, Operation and Troubleshooting User manual Service and maintenance instructions Installation, operation and maintenance instructions

Contents

Carrier 50FF Series Control Manual Manual pdf 32 page image

3212 - COMPONENTS MANAGEMENT12.13. Gas boiler (optional)The control has a proportional output 0/10V (Y2 - connector J5)where a gas boiler with proportional actuator can be connected.The boiler connection is managed by the control, in HEATINGmode, through an ON/OFF signal of the digital output NO5.● In cooling-only units, the boiler is activates in the same way asan electrical heater with one or two stages.● In heat pump units it is possible to choose three differentmethods for controlling the boiler. This can be done on thescreen D. GASCONFIG of the MAIN MENU:- Operation after compressors as one electrical heater stage(both option not compatible).- Operation instead of compressors.- Operation instead of compressors if the outdoor temperatureis lower than the value set (5ºC by default).When the return temperature drops below the value setpoint,the boiler will start to operate. The power control is carried out inaccordance with the temperatures of the supply air and return air.The control compares both temperatures. If the supply temperatureis excessively high, the control limits the power supplied by theboiler despite the demand. This comparison avoids the stratificationof the hot air masses and keeps the supply temperature below thesafety value (55ºC by default), which stops the boiler.Moreover, the control compares the supply temperature and theambient temperature to improve the feeling of thermal comfort.The gas boiler integrates its own operating control, as well as itsown safety devices. The “50FC” control receives a safety signalfrom the boiler in the event of failure (digital input DI5). This signalonly indicates the failure.Important: The “50FC” control manages the start-up and stop ofthe circulation pump of the water circuit. The pump will start-up10 seconds before the boiler. The pump stop will be delayed 180seconds with regard to the boiler.12.14. Heat recovery wheel (optional)The control can manage a rotary heat exchanger connected onthe output NO7 (connector J14), or on the outputs NO1 or NO4of the pCOe expansion card with address 8.This configuration is performed on a screen of the Group G.GENCONFIG (protected by level 3 password).The management may be:● On-off: this will function whenever there is demand forCOOLING or for HEATING and when the temperature conditionsfor outlet, return and mixing air allow for an opening of theoutdoor air damper of 5% for a period of time greater than 10seconds (values set by default).● Variable: the variable wheel speed will depend on the minimumvalue of the exhaust temperature and the recovery temperatureon the wheel.If this value is lower to 6°C, the speed of the wheel decreasesuntil reaching a minimum value fixed of 10% when thetemperature is lower to 1°C (by default).The control of the wheel speed is carried out via a 0/10V (Y1)proportional output on the pCOe expansion card with address 8.12.16. Humidification (optional)The control can manage an on/off humidifier connected on theoutput NO7 (connector J14), or on the outputs NO1 or NO4 of thepCOe expansion card with address 8.This configuration is performed on a screen of the Group G.GENCONFIG (protected by level 3 password).A humidifier with proportional control can be connected on the0/10V output (Y1) of the pCOe expansion card with address 8.The control of the safety devices and alarms is carried out by thehumidifier.The humidifier operating signal is produced when the relativehumidity of the return air is lower than the humidity setpointestablished (55%) minus the differential (5%).12.15. Cooling capacity and electrical energy meter(optional)The control can manage a energy meter. The readings that itrealizes are visualized on the Graphic terminal.The energy meter will be connected on the Field-bus of the μPCMEDIUM board by means of one RS485 card, with address 5(9600 bps, 8 bits of data, 2 stop bits without parity).Calculation of the cooling/heating capacitiesTo perform this calculation, it’s necessary to connect two RS485enthalpic probes: one for the mixing air (placed before the indoorcoil) and other for the supply air (placed after the indoor coil).These probes will be connected on the Field-bus of the controlboard via two RS485 cards, with address 132 for the mixing probeand address 133 for the supply probe.HUMIDIFICATIONC1Zm/2BandHcHrHr: Relative humidity of return airHc: Humidity setpointZm: Dead zoneBand: Humidity control band12.17. Heat recovery coil (optional)The control has a proportional output (Y2 - connector J5) wherea three-way valve can be connected (3-WV) to manage a heatrecovery coil.Note: 3-way valve is supplied for installation outside the unit50FF/FC.Electronic regulation uses the same inputs and outputs for themanagement of the heat recovery coil (HRC) and the hot watercoil (HWC), so these elements are not compatible.The function of the heat recovery coil is to pre-heat the air that willpass through the main indoor coil. For this, it uses the temperatureof an outdoor water installation.The priority of the activation of this coil with respect to thecompressors is established by means of a parameter.