VDH ALFA(NET) 31 User Manual

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User manual ALFA(NET) 31 0-100OC

Cool/Heat Thermostat.

VDH doc. 053950 Version: v1.0 Date: 14-12-2005

Software: ALFA31 0-100OC File: Do053950.WPD Range: 0/+100C per 1C

* Function.

The ALFA(NET) 31 is a digital thermostat for panel mounting. The function from the thermostat can
be programmed for cooling or heating.
The ALFANET

31 has a RS 485 network connection so it can be read out and adjusted on the Alfanet.

* Installation.

On the topside of the ALFA(NET) 31 you can see how the sensor, power supply and relay have to be
connected.
After connecting the ALFA(NET) 31 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) 31 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 shows again in the display.

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* Setting internal parameters.

Next to the adjustment of the setpoint, some internal settings are possible like differential, sensor­offset, setpoint range and the function cooling or heating.
By pushing the DOWN key for more than 10 seconds, you enter the 'internal programming menu'. In
the left display the upper and lower segment, are blinking. With the UP and DOWN keys the required
parameter can be selected (see the parameter table).
If the required parameter is selected, the value can be read-out by pushing the SET key. Pushing the
UP or DOWN keys, together with the SET key allows you to change the value of this parameter.
If no key is pushed for 20 seconds, the ALFA(NET) 31 changes to its normal operation mode.

* Adjustment sensor.

The sensor can be adjusted by using the Sensor Offset (parameter 04). Indicates the ALFA(NET) 31
e.g. 2C too much, the Sensor Offset has to de decreased by 2C.

* Error messages.

In the display of the ALFA(NET) 31 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(NET) 31
Range : 0/+100C, readout per 1C
Supply : 230 Vac (or else see product sticker)
Relay : SPDT 250V/16A(C-NO), 8A(C-NC) (cos phi=1)
Communication: RS485-Network (A,B,GND 3-wire shielded) only at ALFANET 31
Control : by pushbuttons on the front.
Front : Polycarbonate IP65
Sensor : SM 811/2m (1000 at 25C)
Sizes : 35 x 77 x 71,5mm (hwd)
Panel hole : 28 x 70mm (hw)

- Provided with memory protection during power failure.

- Connection with screw terminals on the back side.

- Equipped with self test function and sensor failure detection.

- Special versions are available upon request.

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* Parameters ALFA(NET) 31.

PARA­METER

DESCRIPTION PARAMETER RANGE STANDARD

VALUE

01
02
03
04

Switching differential
Minimum setpoint
Maximum setpoint
Offset temperature sensor

1..15C

0..+100C

0..+100C

-15..+15C

3
0

+100

0

10
11

Startup delay after power failure
Relays on at sensor failure

0..99 min.
0 = No
1 = Yes

0
0

15

16
17
18

19
20

Function cooling or heating

Switch on delay relays 1)
Switch off delay relays 1)
Parameter 16/17 in sec. or min.

Minimum on-time relays
Minimum off-time relays

0 = Cool
1 = Heat

0..99

0..99
0 = sec.
1 = min.

0..99 min.

0..99 min.

0

0
0
0

0
0

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

-

-

-

-

-

1) On active delay led 'on' blinks.

* Function Diagram.

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* Dimensions.

* Connection Diagram.

* Address.

VDH Products BV Tel: [phone]
Produktieweg 1 Fax: [phone]
9301 ZS Roden Email: [e-mail]
The Netherlands Internet: www.vdhproducts.nl