User manual ALFANET 75 Cool/Defr. Thermostat
Contents
1. Sensor adjustment The temperature sensor can be adjusted by using the Offset control sensor parameter 05 The defrost sensor can be adjusted by using the Offset defrost sensor parameter 07 For read out of the defrost sensor on the display use parameter 06 Indicates a sensor e g 2 C too much the according Sensor offset parameter has to be decreased with 2 C Error messages In the display of the ALFANET 75 the following error messages can appear LO Minimum alarm Solution E1 E2 HI Maximum alarm Check if sensor is connected correctly E1 Control sensor failure Check sensor 10000 25 C E2 Defrost sensor failure Replace sensor EEE Settings are lost Solution EEE Reprogram the settings L In case of sensor short circuit the display alternates between error code E and L as indication for a short circuit sensor H In case of open circuit sensor the display alternates between error code E and H as indication for a open circuit sensor Reset Alarm When a error messages appears it can be reset by pushing the SET key The function of this key depends on parameter P37 Alarm As a failure or alarm occurs an error message is shown in the display The ALFANET 75 remembers it s error message although it is already solved The error message is resettable with the SET key As if after pressing the SET key reset alarm the alarm still is not solved than the ALFANET 75 displays the temperature and th2. gt gt o c c c c a T o L ec of oc oo 2 v p w a Cool Fan SUPPLY 2x SM811 12Vac Temp sens Defrost Trafo 3VA 230 12Vac VDH art nr 350 010073 Function diagram Address VDH Products BV Produktieweg 1 9301 ZS Roden The Netherlands Function COOL Diff 1 15 C Setpoint 50 50 C Tel Fax Email Internet 31 0 50 30 28 900 31 0 50 30 28 980 info vdhproducts nl www vdhproducts nl
3. 7 segments display COMPR FAN and DEFR On display thru C key The three Relays have one common Type Range Supply Read out Status Led s Relays Control Front Sensor Dimensions Panel cutout Accuracy Ry 1 Cool SPST NO 250V 8A cos p 1 Ry 2 Fan SPST NO 250V 8A cos p 1 Ry 3 Defrost SPDT NO NC 250V 8A cos p 1 Thru pushbuttons on front Polycarbonate IP65 2x SM 811 2m PTC 10000 25 C 35 x 77 x 71 5mm HWD 29 x 70mm HW 0 5 96 of range Provided with memory protection during power failure Equipped with self test function and sensor failure detection Connection with screw terminals Special version on request available Dimensions 77 SEES ALFA 3x gt 6 5 60 SSS SSS SS eS 65 H Qo Connections REMARK Connect a 250 Ohm Resistor between shield Line A and Line B at both CABLE ENDS us of RS485 Network 2 wire with shield Ge wo Qs oO lt ow N coy x c os 1 Loe oj o os oo Si amp t e NN ALFANET 75 cgo 29 14 13 12 11 N I 3 NYY R WY Y WY XL ML M o o cjs Uu ojos S c o o o o Elo vo o c S S c EIS N E 1 1 1 1 ojo E a e e eo oju 42 o gt
4. User manual COMFR ___ FAN______DEFR ALFANET 75 C Cool Defr Thermostat with fan control mel VDH doc 002465 Version v1 1 Date 15 02 2005 Software ALFA NET 75 File Do002465 WP8 Range 50 0 50 0 C Description The ALFANET 75 is a cool defrost thermostat with various defrost and fan control settings And it is controllable on the PC thru the ALFANET PC INTERFACE Installation On the top side of the ALFANET 75 is shown how the sensor power supply and relays has to be connected After connecting the ALFANET 75 to the power supply a self test function is started As this test is finished the measured temperature of the temperature sensor control appears in the display Control The ALFANET 75 thermostat can be controlled by four push buttons on the front These keys are SET view change the setpoint UP increase value DOWN decrease value C hidden push button above SET key and behind C symbol View setpoint By pushing the SET key the setpoint appears in the display The decimal point of the last display starts blinking to indicate this After a few seconds after releasing the SET key the setpoint disappears and the measured temperature is shown again Changing setpoint Push the SET key and the setpoint appears in the display Release the SET key Now push the SET key again together with the UP or DOWN keys to change the setpoint After a few seconds after releasing the SET key the s
5. e error message alternated is the alarm solved then the error message disappears and the temperature is displayed normally Fan control The ALFANET 75 has several parameters for fan control Normally the fan is always active accept for one of the following parameters is set to 1 the fan can be stopped Parameter 20 1 Fan switch differential active The fan is only active when the defrost temperature is parameter 21 lower than the measured product temperature Fanon Toe lt T contro Tug P21 As there are no further conditions to switch the fan off Parameter 25 26 Fan on delay after defrost The fan is switched off during defrost and to prevent blowing in hot air in the cabin after defrost and the dripping off time parameter 27 there are two conditions which can be set a The fan is blocked until the defrost sensor measures a temperature lower than the temperature setting of parameter 25 b The fan is blocked until the defrost delay time of parameter 26 has stopped Unless the defrost sensor has reached the temperature setting of parameter 25 Parameter 22 1 Compressor off than Fan off The fan deactivates as the compressor deactivates with a delay of parameter 23 minutes Provided that there are no other conditions to deactivates the fan Defrost control The automatic defrost is started by the defrost cycle time P30 and stopped by the maximum defrost time P31 or sooner by reaching the maximum defrost tem
6. eter 10 11 in Sec or Min O Sec 1 Min Minimum on time Cooling 0 99 Minutes Minimum off time Cooling 0 99 Minutes Switching differential Fan active O No 1 Yes Switching differential Fan 0 50 C Fan off as Compressor is off OzNo 1 Yes Switch off delay Fan 0 90 Minutes Defrost mode O only fan relay OzNatural l only defrost relay 1 Hotgas Elec Switch on delay temp fan after defrost 50 50 C Switch on delay time fan after defrost 0 90 Minutes Dripoff time 0 90 Minutes Defrost interval time 1 99 Hours Maximum defrost time 0 99 Minutes End of defrost temperature 50 50 C Compressor on while defrosting O No 1 Yes Defrosting on compressor time OzNo 1 Yes Temperature display locked during O No 1 Yes defrost cycle Start with defrost after power up OzNo 1 Yes Defrost on delay after power up 0 99 Minutes Alarm mode OzNone 1 Absolute 2 Relative Minimum alarm setpoint 50 50 C Maximum alarm setpoint 50 50 C Time delay minimum alarm 0 99 Minutes Time delay maximum alarm 0 99 Minutes Control delay after power failure 0 99 Minutes Compressor on at control sensor failure OzNo 1 Yes Compressor off at minimum alarm OzNo 1 Yes Time correction factor at realtime clock Network number Software version Production Year Production Week Serial number x1000 Serial number units Technical details ALFANET 75 Cool Defrost Thermostat 50 0 50 0 C 12 Vac 16 5Vdc 5 10 9 digit
7. etpoint disappears and the measured temperature is shown again Status of the Relays By pushing the hidden C key the display shows the status of the relays Each display segment shows the status of the relay output showing 02 off and 1 on The code 110 means relay 1 compr en relay 2 fan are on and relay 3 defr is off Manual starting stopping of defrost The defrost cycle is automatic started and stopped These defrost settings thru internal parameters Stop defrost If there is a defrost cycle the defrost can be manually stopped by pushing the UP and the DOWN key simultaneously Start defrost If there is no defrost cycle the defrost can be manually started by pushing the UP and the DOWN key simultaneously Setting internal parameters Next to the adjustment of the setpoint some internal settings are possible like differentials sensor adjustments setpoint range compressor fan defrost and alarm settings By pushing the DOWN key for more than 10 seconds you enter the internal programming menu In the left display the upper and the lower segments are blinking Over the UP and DOWN keys the required parameter can be selected see table for the parameters If the required parameter is selected the value can be read out by pushing the SET key Pushing the UP and DOWN keys allows you to change the value of this parameter If after 20 seconds no key is pushed the ALFANET 75 changes to it s normal operation mode
8. perature P32 Further has the ALFANET 75 additional parameters to control defrost Parameter 24 Defrost mode The ALFANET 75 has two defrost modes P24 0 While defrosting only the Fan activates Natural defrost P24 1 While defrosting the relay DEFR activates Hotgas Electrical defrost Parameter 34 0 Defrost at fixed interval time In this case parameter 30 is the chosen interval time Parameter 34 1 Defrost based on total Compressor time In this case the Defrost is started as the Compressor has been activated for parameter 30 hours Parameter 36 1 The ALFANET 75 starts with Defrost on Power up After Power up the ALFANET 75 first starts with a delay of parameter 37 minutes before starting Defrost while in delay the ALFANET 75 works normally Parameter 33 1 Compressor active at Defrost P24 1 For hot gas Defrost systems the Compressor needs to be activated while defrosting After Defrost the Drip off time parameter 27 starts During this time the defrost relay and the compressor are not active so the Cool unit can drip off Parameters ALFANET 75 Para Description Parameter Range Default meter Value Switching differential 15 0 C Minimum setpoint eo Seb Cc Maximum setpoint 50 50 C Read out above 10 C per 1 C OzNo 1 Yes Offset Control sensor 15 0 415 0 C Read out Defrost sensor Offset Defrost sensor 15 0 415 0 C Start up delay Cooling 0 99 Switch off delay Cooling 0 99 Param
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