Temperature Controller RT-10

Assignment and functional capabilities

The temperature controller ТC -10, which structure includes the electronic module (further under text EM) and platinum resistive temperature detector (PRTD), together with control valves with rotary actuators (RA) is intended for the control and regulation of temperature in systems of heating and hot water supply.

The controller depending on a variant of implementation can have one or two independent control channels. Each channel allows maintaining temperature in a control loop according to temperature tables for workdays and weekends, adjusting its value depending on ambient temperature or limiting the maximal temperature of the heat-carrier in the return pipeline, forming a corresponding control voltage for RA. Irrespective of temperature control, each channel can control work of the pump under the separate time or temperature curve.

The single-channel controller can be used for a contour of heating or hot water supply.

The two-channel controller can be used for independent simultaneous control in a contour of heating and a contour of hot water supply, or other combination of independent contours.

Characteristics of one control channel:

Each control channel can use up to three temperature detectors and the common for both channels the ambient temperature detector (see Figure 2). Connection to detectors is carried out by 4-wire cable in length up to 200 m. The range of temperature measurement is from a minus 60°С up to plus 160°С. The maximal error of the electronic device at temperature measurement is no more than ±0.4°С (typical value of an error is ±0.1°С).

There are two independent outputs - analog and key:

analog output – for connection of the control valve, which is controlled by voltage (in the range 0 – 10V at load resistance> 1 kiloohm );

key output – for forming of a signal of switching-on of a pump contactor (~24V x 0,6А, 50Hz).

Figure 2. The variant of usage of one channel of the temperature controller ТC-10

The specified temperature is determined by time/temperature curve (8 points on day with the step of 10 minutes, a range of specified temperature tuning for each point is 10 … 99°С with the step 1°С).

There is an opportunity of set the weekend table (the time of weekend and the temperature of weekend).

There is a mode of the maximal heat-carrier temperature restriction in the return pipeline: when the temperature of the heat-carrier in the return pipeline exceeds a preset value, the controller turns to a mode of restriction of the temperature of "return water" and remains in it until the temperature in the return pipeline will not lower below a preset value. Value of the maximal temperature in the return pipeline depends on temperature of the heat-carrier in the supply pipeline and is determined by the linear curve of "return water" (it is set on two points). Ranges of installation of temperatures: in the submitting pipeline is 10 … 150°С, in the return pipeline is 10 … 99°С).

Control of a key output is carried out under time tables separately for the workdays and weekends. Each table allows to set two cycles of switching - on/off in day. The discreteness of time set is 10 minutes.

Fast change of the device configuration is carried out through the menu. Variants of a configuration:

1. For regulation the one PRTD is used. Regulation is carried out on one temperature according to the time-temperature curve, the weekend table and the specified operating mode.
   
2. For regulation two PRTD are used. Regulation is carried out on one temperature according to the time-temperature curve, the weekend table and the specified operating mode. Correction on ambient temperature is carried out according to the curve of weather compensation.
   
3. For regulation three PRTD are used. Regulation is carried out on one temperature according to the time-temperature curve, the weekend table and the specified operating mode. Restriction of the maximal value of the heat-carrier temperature in the return pipeline is carried out. It depends on the heat-carrier temperature in the supply pipeline and is set by the curve of "return water".
   
4. For regulation four PRTD are used. Regulation is carried out on one temperature according to the time-temperature curve, the weekend table and the specified operating mode. Correction on ambient temperature is carried out according to the curve of weather compensation. Restriction of the maximal value of the heat-carrier temperature in the return pipeline is carried out. It depends on the heat-carrier temperature in the supply pipeline and is set by the curve of "return water".
   
5. Switching of operating modes is carried out through the menu. Possible operating modes:

• «Full» – regulation is carried out under time-temperature curve and the weekend table. Thus correction on ambient temperature and "return water" functions according to the set configuration of the channel. The circulating pump works under curves of workdays and weekends.
  
• «Workday» – regulation is carried out under time-temperature curve. Thus correction on ambient temperature and «return water» functions according to the set configuration of the channel. The circulating pump works under curves of workdays.
  
• «Weekend» – regulation is carried out under weekend table. Thus correction on ambient temperature and «return water» functions according to the set configuration of the channel. The circulating pump works under weekend tables.
  
• «Safety» – in this mode the control channel provides only freezing water protection (the temperature in a control loop doesn't go down below 5°С). When the ambient temperature goes down below 5°С the circulating pump is switched on.

General characteristics:

• Automatic saving of last 500 measured and set temperatures in archive. The interval of recording in archive is established in a range from 1 up to 90 minutes.
  
• All set parameters are saved in non-volatile memory .
  
• Restricted access to changeable parameters by means of the password.
  
• The information is represented on 4-row 16-symbolical display.
  
• Direct connection to the personal computer (RS-232) with an opportunity to set regulation parameters through the software "Sempal DM".
  
• The possibility of equipment by interface RS-485 (allows to contact with a controller through the common modem connected to the heatmeter SVTU-10M).
  
• Protection class of the case IP65.
  
• Supply voltage is ~24V, 50 Hz.
  
• Power consumption is no more than 5 VA.
  
• Overall dimensions of the electronic module are 180 x 100 x 35 mm.
  

The controller also can be delivered in the complete set with standard device enclosure, that allows to connect easily to it any control valves (see Figure 3).

Figure 3. Enclosure layout for mounting of the controller

The note: the present device enclosure configuration is presented for a two-channel variant of controller ТC-10. For a single-channel variant, the relay of switching-on of the actuator R2 and connector block KV3 are not used and can be absent.

The Digital Temperature Controller ТC-10. Operating Manual (pdf, 1.8Мб)