Alfa 71 Thermostat Range
A compact three stage thermostat for panel mounting with push buttons on the front, a neutral zone and a 0/+10Vdc P(I) output.
The Alfa 71-PI has a default program with the function cooling/heating and a minimum/maximum temperature alarm. The thermostat can also be programmed with three stage cooling and three stage heating.
This model has a range of either -50/+50°C or 0/+100°C. Temperatures above -10°C can be read-out per 0.1°C
The Alfa 71-PI is supplied with 12Vac. A special transformer can be optionally be delivered.
The Alfa-71 MOD variation is a compact modulating thermostat specially designed for controlling left/right valves. Besides a P(I) adjustment, it is possible to enter to run time of the valve (the time required from completely closed to completely open). To avoid deviations it is possible to enter a reset time, during which the valve will be fully opened or closed (adjustable). Because of this, the valves always runs exactly without feedback from the valve.
The Alfa-71 Spec variation has a range of -50 to +50°C. The range for the 0/10V output is adjustable. This enables the controller to be used for various purposes.
On the Alfa 71-PI Solid State variation the P(I) output can be used as a 0/+10Vdc output for proportional valves or as a modulating output for controlling a solid state relays (where they can be used as a proportional pulse/pause output).
The Alfa-71 RTDN variation has a range of -50/+50°C or 0/+100°C. It is possible to program different switching times for weekdays and weekends. Switching from the day setpoint to the night setpoint is done by an internal real time clock. A second temperature sensor can optionally be connected, so that the temperature control can be based on the average of the two sensors.
The Alfa 71-PI has a default program with the function cooling/heating and a minimum/maximum temperature alarm. The thermostat can also be programmed with three stage cooling and three stage heating.
This model has a range of either -50/+50°C or 0/+100°C. Temperatures above -10°C can be read-out per 0.1°C
The Alfa 71-PI is supplied with 12Vac. A special transformer can be optionally be delivered.
Variations
The optional Alfanet 71 variation has an additional RS-485 network connection for read-out and data logging on the Alfanet PC software.The Alfa-71 MOD variation is a compact modulating thermostat specially designed for controlling left/right valves. Besides a P(I) adjustment, it is possible to enter to run time of the valve (the time required from completely closed to completely open). To avoid deviations it is possible to enter a reset time, during which the valve will be fully opened or closed (adjustable). Because of this, the valves always runs exactly without feedback from the valve.
The Alfa-71 Spec variation has a range of -50 to +50°C. The range for the 0/10V output is adjustable. This enables the controller to be used for various purposes.
On the Alfa 71-PI Solid State variation the P(I) output can be used as a 0/+10Vdc output for proportional valves or as a modulating output for controlling a solid state relays (where they can be used as a proportional pulse/pause output).
The Alfa-71 RTDN variation has a range of -50/+50°C or 0/+100°C. It is possible to program different switching times for weekdays and weekends. Switching from the day setpoint to the night setpoint is done by an internal real time clock. A second temperature sensor can optionally be connected, so that the temperature control can be based on the average of the two sensors.
Technical Specification
Housing: Black ABS plastic
Dimensions: 35 x 77 x 71.5 mm
Front: Polyester with Screw terminals
Power input: 12 Vac, 50/60 Hz, (-10/+5%)
Measure range: -50/+50°C or 0/+100°C options
Accuracy: ± 0.5% of the range
Sensor: SM 811 (PTC sensor, 1000 Ohm at 25°C) (not included)
Relay: Cooling SPST contact 250V/5A (NO), heating SPST contact 250V/5A(NO), alarm SPDT contact 250V/5A(NO/NC)(common, not inductive)
Functions: Cooling, Heating, Alarm relay