VDH ALFA 15 User manual

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User manual
ALFA 15 and
ALFANET 15
Cool/Defrost Thermostat.
VDH doc. 061283 Version: v2.1 Date: 05-12-2007
Software: 043376_ALFA 15/25/35 File: Do061283.wpd Range: -50/+50C per 1C
* Function.
The ALFA(NET) 15 is a digital thermostat for rail mounting. The thermostat controls the cooling and
defrost. The temperature readout is in hole degrees Celsius.
Defrost will be done by temporarily switching off the cooling (natural defrost). The defrost starts on
intervals or on compressor runtime. The defrost stops on time.
The ALFANET 15 has a RS 485 network connection so it can be read out and adjusted on the Alfanet.
*Installation.
On the connection diagram of the ALFA(NET) 15 you can see how the sensor, power supply and relay
have to be connected.
After connecting the ALFA(NET) 15 to the power supply, a self test function is started. As this test is
finished the measured temperature appears in the display.
When the relay is activated, the led 'on' will light-up in the display.
*Control.
The ALFA(NET) 15 thermostat can be controlled by three pushbuttons on the front. These keys are:
SET - view / change the setpoint.
UP - increase the setpoint.
DOWN - decrease the setpoint.
*Viewing setpoint.
By pushing the SET key the setpoint appears in the display. The led 'set' starts blinking. A few seconds
after releasing the SET key the setpoint disappears and the measured temperature is shown in the
display.
*Changing setpoint.
Push the SET key and the setpoint appears in the display. Release the SET key. Now push the SET
key again and together with the UP or DOWN keys the setpoint can be changed. A few seconds after
releasing the keys the measured temperature is show in the display.

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*Starting/stopping defrost.
The defrost cycle i s a u to m a t i c a l l y s t a r t e d a n d s t o p p e d . P r o g r a m m i n g b y t h e i n t e r n a l p a r a m e t e r s . D u r i n g
defrost the led 'defrost' will light-up.
If there is a defrost cycle, the defrost can be stopped by hand, pushing the UP key and then the SET
key, while the UP key is held.
If there is no defrost cycle, the defrost can be started by hand, pushing the UP key and then the SET
key, while the UP key is held.
*Adjustment sensor.
The sensor can be adjusted by using the ‘Sensor Offset’ (parameter 04). Indicates the ALFA(NET) 15
e.g. 2C too much, the Sensor Offset has to be decreased by 2C.
*Error messages.
In the display of the ALFA(NET) 15 the following error messages can appear:
Er - Sensor broken. Solution:
- Check if the sensor is connected correctly.
- Check the sensor (1000at 25C).
- Replace the sensor.
EE - Settings are lost. Solution:
- Reprogram the settings.
* Technical details.
Model :ALFA 15 Cool/Defrost Thermostat
ALFANET 15 Cool/Defrost Thermostat with Network
Range :-50/+50C, readout per 1C
Supply :230 Vac / 1,2VA 50/60Hz (or else see product sticker)
Relay :SPDT 250V/16A(C-NO), 8A(C-NC) (cos phi=1)
Control :by pushbuttons on the front.
Communication :RS 485 Network (2xtwisted pair shielded) only at ALFANET model.
Front :Polycarbonate IP65
Sensor :SM 811/2m (1000at 25C)
Sizes :90 x 53 x 58mm (hwd)
Panel hole :46 x 53mm (hw)
- Provided with memory protection during power failure.
- Connection with screw terminals on the backside.
- Equipped with self test function and sensor failure detection.
- Special versions are available upon request.
*Setting internal parameters.
Next to the adjustment of the setpoint, some internal settings are possible like differential, sensor-
offset, setpoint range and the defrost function.
By pushing the DOWN key for more than 10 seconds, you enter the 'internal programming menu'. In
the left display the upper and lower segments are blinking. With 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 or DOWN keys allows you to change the value of this parameter.
If no key is pushed for 20 seconds, the ALFA(NET) 15 changes to it's normal operation mode.

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*Parameters ALFA(NET) 15 .
PARA-
METER
DESCRIPTION PARAMETER RANGE STANDARD
VALUE
01
02
03
04
Switching differential
Minimum setpoint
Maximum setpoint
Offset temperature sensor
1..15C
-50..+50C
-50..+50C
-15..+15C
3
-50
+50
0
05
06
Compressor start-up protection
0 = start-up delay in seconds
1 = start-up delay in minutes
2 = delay between switch off and switch on in
minutes
3 = delay between switch on and switch on in
minutes
Compressor start-up time belonging to
parameter 05
0..3
0..99
0
10
07
08
09
10
11
12
13
14
15
Defrost cycle time
Defrost time
Defrost delay after power failure
(if parameter 14 is 1)
Startup delay after power failure
Relay on at sensor failure
Defrost cycle time based on compressor on
time
Temperature display locked during defrost
cycle
After power failure starting with defrost cycle
Maximum time display locked after defrost
(if parameter 13 = 1)
1..99 hours.
0..99 minutes
0..99 minutes
0..99 minutes
0 = No, 1 = Yes
0 = No, 1 = Yes
0 = No, 1 = Yes
0 = No, 1 = Yes
0..60 minutes
12
15
0
0
0
0
0
0
5
90
95
96
97
98
99
Network number
Software version
Production year
Production week
Serial number (x1000)
Serial number (units)
1..250
0..255
00..99
1..52
0..255
0..999
1
-
-
-
-
-
* Function diagram.

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*Dimensions. *Connection diagram.
*Address.
VDH Products BV Tel: +31 (0)50 - 30 28 900
Produktieweg 1 Fax: +31 (0)50 - 30 28 980
9301 ZS Roden Email: [e-mail]
The Netherlands Internet: www.vdhproducts.nl