Carrier AQUASNAP 30RA/RH Operation & Maintenance Instructions Manual

Carrier AQUASNAP 30RA/RH Operation & Maintenance Instructions Manual Manual pdf 5 page image

53 - HARDWARE DESCRIPTION3.1 - GeneralFigure 13.2 - Electrical supply to boardsAll boards, except the PD-RCPM board, are supplied from acommon 24 V a.c. supply referred to earth.CAUTION: Maintain the correct polarity when connectingthe power supply to the boards, otherwise the boards may bedamaged.In the event of a power supply interrupt, the unit restartsautomatically without the need for an external command.However, any faults active when the supply is interrupted aresaved and may in certain cases prevent a circuit or unit fromrestarting.3.3 - Light emitting diodes on boardsAll boards continuously check and indicate the properoperation of their electronic circuits. A light emitting diode(LED) lights on each board when it is operating properly.• The red LED flashing for a 2 second period on the NRCP-BASE board indicates correct operation. A different rateindicates a board or a software failure.• On dual-circuit units or units equipped with optionalboard, the green LED flashes continuously on all boardsto show that the board is communicating correctly over itsinternal bus. If the LED is not flashing, this indicates aSIO bus wiring problem.• The orange LED of the master board flashes during anycommunication via the CCN bus.3.4 - The sensorsPressure sensorsTwo types of electronic sensors are used to measure the suctionand discharge pressure in each circuit.ThermistorsThe evaporator water sensors are installed in the entering andleaving side. The outdoor temperature sensor is mounted belowthe control box. An optional water system temperature sensorcan be used for master/slave assembly control (in the case ofleaving water control).In heat pump units a sensor placed on an air heat exchangerpipe ensures defrost operation.Legend1 CCN connector2 Red LED, status of the board3 Green LED, communication bus SIO4 Orange LED, communication bus CCN5 Remote master board customer control connection contacts6 Remote slave board customer control connection contacts7 Master board customer connection relay outputs8 Slave board customer connection relay outputs9 Master NRCP basic board10 Slave NRCP basic boardThe control system consists of an NRCP-BASE board forsingle-circuit units and two NRCP-BASE boards (a master anda slave board) for dual-circuit units. Heat pump units equippedwith optional additional heater stages use an additional board,type PD-AUX. All boards communicate via an internal SIO bus.The NRCP-BASE boards continuously manage the informationreceived from the various pressure and temperature probes. TheNRCP-BASE master board incorporates the program thatcontrols the unit.The user interface consists of two display blocks with up to 26LEDs and 16 buttons (according to unit type). It is connectedto the main basic board and gives access to a full array ofcontrol parameters.567 891031 42 3