Carrier 50FF Series Control Manual
Also see for 50FC Series: Installation, operation and maintenance instructionsControls, Start-Up, Operation and TroubleshootingUser manualService and maintenance instructionsInstallation, operation and maintenance instructions
                                                                                                  | |
Contents
| 
9720. TROUBLESHOOTING● The unit does not switch on (the power LED on the main boardis switched off).Check:1. The presence of main power;2. That the transformer output voltage is 24 Vac/Vdc;3. That the power supply connector at 24 Vac/Vdc is correctlyinserted;4. That the overload fuse is intact.● When switching on, there are general problems with the LCD(strange characters, blank display).Check:1. That the software in the flash is correct;2. The pLAN address of the pCOc and on the terminal (check thatthey comply with the requirements of the current application);3. The connection between the Graphic terminal and the μPCMEDIUM board.● Erroneous readings of the input signals.Check:1. The correct power supply to the μPC MEDIUM board andprobes;2. The separation between the power supply of the digital inputsand that of the μPC MEDIUM board. A 24 Vac/24 Vac, 5 VAtransformer can be used.3. That the cables from the probes are connected according tothe instructions;4. That the probe cables are located far enough away frompossible sources of magnetic interference (power cables,contactors, high voltage cables or cables connected to unitswith high current peaks);5. That there is not a high level of heat resistance betweenthe probe and the sensor cap (if present). If necessary,apply conductive paste or oil into the caps to ensure goodtemperature transfer.6. If there is a probe error or μPC MEDIUM board conversionerror, the checks to be carried out would vary depending onthe type of probe:Active temperature/humidity probes with 0/1V signal:Using a voltmeter, measure the probe signal between the Bnand GND terminals and check that the voltage correspondsto the temperature/humidity value: 1 mVdc corresponds to0.1% HR.Example: reading 200 mVdc (0.2 Vdc), the probe sends asignal which corresponds to 20%RH; applying the same logic,0 mVdc corresponds to 0ºC/0% RH;Pressure probes:If there are errors when reading these probes, check that:- The analogue inputs of these sensors are set to receive4/20 mA signals;- Check that the probe capillary is not blocked.- The full scale set by the software corresponds to that usedby the sensors.Using a voltmeter to measure the voltage between the Bnand GND terminals, an indication is obtained of the currentprobe signal, considering that the input has an impedanceof 100Ω, by applying the formula I= V/R.The pressure value “Ps” sent by the probe could becalculated as follows (FS = full scale):Ps = (Vmed/100 - 0.004) x (FSmax - FSmin) / 0.016 + FsminExample: the probe used has Fsmin = -0.5 bar, Fsmax = 7bar; the voltage read is equal to Vmed = 1.0 Vdc.The pressure Ps that the probe is measuring is thus:Ps = (1.0/100 - 0.004) x [7 - (-0.5)] / 0.016 + (-0.5) = 2.3 barNTC probes:The probe signal is a resistive value which depends on thetemperature.The following table indicates some of the resistance valuesfor different temperatures. By disconnecting the input probeand measuring the resistance with a multimeter, the tablecan be consulted for the corresponding temperature value.● To check the setting of the probe inputs.Switch off the μPC MEDIUM board and perform the followingmeasurements with a tester between the Bn and AVSS probeinputs:● Unusual alarm signal from the digital input.Check whether the alarm signal is present in the input, measurethe voltage between the “IDC" common terminal and the digitalinput terminal which indicates the alarm “IDn”:- if voltage is present (24 Vac or Vdc, depending on thepower supply used for the digital inputs), the contact of theconnected alarm device is closed;- if the voltage is near 10 Vac or 10 Vdc (see above) thecontact is open.Unless otherwise expressly stated, the control generates analarm when detecting open contacts.probe type voltagemeasuredNTC 2.5 V4/20mA 0 V0/1V; 0/5V; 0/10V 0 V°C kΩ °C kΩ °C kΩ-20 67,7 0 27,2 20 12,0-15 53,3 5 22,0 25 10,0-10 42,2 17 17,9 30 8,3-5 33,8 15 14,6 35 6,9 |
Related manuals for Carrier 50FC Series
This manual is suitable for:
manualsdatabase
Your AI-powered manual search engine