INTIEL TD-3.1.1 Programmable Differential Thermostat User Manual

: June 2, 2024
: INTIEL

Table of Contents

INTIEL TD-3.1.1 Programmable Differential Thermostat
Application
Operation
- Programming
Emergency alerts
Warranty
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INTIEL TD-3.1.1 Programmable Differential Thermostat

Application

Programmable Differential Thermostat DT-3.1.1 is used for domestic hot water preparation in water heaters, where the heating energy is provided in combined way, by solar panels (fireplace) and electrical heating elements. It is designed to control the circulation pump operation, installed in the water circuit between the solar panels (fireplace) and the water heater serpentine, thus regulating the heat exchanging between them.

Operation

The thermostat has two temperature sensors mounted respectively in the boiler and solar panels. During an operation the thermostat monitors the following parameters:

∆Т, ∆t – adjusted and current (real) difference between the water heater and solar panel temperatures. ∆Т can be adjusted in the range of 2 up to 20°С. The default setting is 10°С
Wb – adjusted temperature level of the water heater to which it can be heated from the solar panels. The temperature can be adjusted in the range between 30 and 90°С. The default setting is 60°С.
Tbmax – maximum allowed water heater temperature. It can be adjusted in the range between 80 and 100 °С. The default setting is 95°С.
Tpmin – minimum temperature level of the solar panel. It can be adjusted in the range between 20 and 50 °С. The default setting is 40°С.
Tpmax – maximum allowed temperature of the solar panel. It can be adjusted in the range between 80 and 110°С. The default setting is 105°С.
Tpdefrost – defrost temperature level of the solar panel. It can be fixed in the range between -20 up to 10°С. The default setting is “- -“, without defrosting.
H (Thset) – set temperature in the boiler, up to which it can be heated by electric heaters. It is set in the range from 5 to Wb-5 ° С. Default setting 45 ° C;
Pr – priority of heating the boiler by electric heaters.
tc – delayed cooling time of the boiler. It is set in the range from 0 to 5 hours. Default setting 0.
Tbmin – minimum water temperature level in the water heater. It cannot be adjusted. The default setting is 20°С

Differential Thermostat DT-3.1.1 operation depends on the temperature sensor states, as follows:

Normal operation

In case of a positive temperature difference Δt between the solar panel (stove) and the water tank, greater than the set ΔT of 3 ° C, the pump starts operation, thus heating the tank from the panel.
A timer is being switched on when ∆t gets equal to ∆T, as from this moment the controller counts 10 minutes of circulation pump operation. That time can vary within above range of 10 minutes as decreasing the difference between ∆t and ∆T to 0 relates to less operation time of the pump, which the device count automatically. The pump operation stops if the previous mentioned difference becomes 0 or less than 0.
Heating the water tank under the above conditions can be made only until the temperature in the water tank gets equal to the set one Wb, then the pump switches off, stopping the heating.
If the above conditions are fulfilled, and the solar panel (stove) temperature falls below Tpmin, the pump stops, even the following conditions ∆t>∆Т+3° and Тб< Wб are fulfilled.
If the temperature of the panel falls below Tpdefrost the pump is being switched ON, although it has been switched off because solar panel temperature is below Tpmin.
Heating the boiler with electric heaters. By setting Pr, the heating priority is selected as follows:
- 0 – heating with electric heaters is disabled;
- 1 – heating with electric heaters is allowed when there are no conditions for heating from the panel, the temperature in the boiler is lower than Thset and 10 minutes have passed during which the pump has not worked.
- 2 – heating with electric heaters is allowed until the The set is reached without taking into account the condition of the pump.

Default setting – 1.
Heating with electric heaters is prohibited when the “vacation” mode is activated.

VACATION Mode – The current mode is useful in case of not using the water tank for a long time. In case of the mode activation the adjusted temperature is being automatically set to 40 °С, as the heating elements switching on is not allowed. The pump is being switched on when it is necessary in order to prevent the overheating of the tank or the solar
panel. The mode can be activated by means of pressing “PROGRAM” button for 3 seconds, as after its releasing on the display appears ON/OFF indication. “HoL” flashes on the display.

Emergency operation

If during water heater warming the solar panel (stove) temperature exceeds Tpmax , the circulation pump will be switched on by force in order to provide the solar panel cooling. The previous mentions will be done despite of the water heater temperature can exceed Wb.
If at the previous mentioned emergency case, the water heater temperature reaches its maximum allowed temperature level Tbmax, the circulation pump will be stopped despite of this state can causes overheating of the solar panel. In this way the temperature at the water heater as an overheating protection has a higher priority compare to the temperature of the solar panel (stove).
When the temperature Tb is above the set Wb and is above the temperature of the panel Tp, in order to avoid overheating of the boiler, if there is no hot water consumption the pump is switched on until the temperature of the boiler Tb drops to the set Wb. This cooling can be delayed for 0 to 5 hours. Sets via parameter tc (default setting is 0). When combined heating with electric heaters is used, the settings for the electric heaters must be lower than Wb.

Water tank and solar panel protection
When the water tank temperature Tb is above the assigned one Wb and in the same time is grater than the solar panel temperature, in terms of preventing water tank overheating the circulation pump will be switched on. Its operation goes on until the water tank temperature Tb is being decreased to the assigned one Wb. In this case the water tank gives the excessive heat, as it cool itself through the solar panel. When a combine heating with electrical heating elements is being used, then the assignation of the of the electrical part is to be a little bit lower than Wb.

Front panel indications
On the front panel are located all elements for control and programming. These are three digital display, ten light indications and two buttons, “SELECT” and “PROGRAM”. The front panel vision is shown on Figure 1 bellow.

Indications on the digital display

1| Tb – shows the water heater temperature
2| Tp – shows solar panel temperature
3| ∆Т – shows the adjusted temperature difference between the solar panel and the water heater
4| Wb – shows the water heater temperature level which has to be kept
5| Tb max – shows the maximum allowed water heater temperature
6| Tp min – shows the fixed minimum temperature level of the solar panel
7| Tp max – shows the adjusted maximum temperature level of the solar panel
8| Tp defrost – shows the adjusted temperature level for solar panel defrosting
9| Pump – shows the circulation pump operation
10

11

| Heater – Electrical heater is ON

Alarm – shows emergency operation

Programming

The Thermostat automatically goes into start mode, after connection to the power supply, showing the water heater temperature:

Inspection of water heater and solar panel temperatures.
When the Thermostat is not in program mode, by consecutively pressing of “SELECT” button the digital display indication is being switched over between the water heater temperature and the solar panel one, activating their relevant indications Tb or Tp.
Inspection of temperatures mentioned at points 2.1 – 2.6 (see II. Operation, page 2.)
After pressing “PROGRAM” button the digital display will automatically show the temperature mentioned at 2.1 – ∆Т. Then, after pressing “SELECT” button five times more the temperatures 2.2 – 2.6 will be indicated. Next pressing of “SELECT” button will return you to position 4.1. (Inspection of water heater and solar panel temperatures). The temperature inspection does not change the current operation of the Thermostat.
Programming of temperatures 2.1 – 2.6.
The digital display will automatically show the temperature mentioned at 2.1 – ∆Т, after pressing “PROGRAM” button. The temperature indication will start blinking 10 times, after second pressing of “PROGRAM” button. The adjustment of the same temperature can be done during the blinking time by repeatedly pressing of the “SELECT” button, within the possible adjusted range. If until the 10th blink “SELECT” button is not pressed or “PROGRAM” button is pressed, the last blinking value will be accepted as adjusted one concerning the relevant temperature. If you want to make some corrections concerning just adjusted temperature, you need to press “PROGRAM” button again, thus returning to above mentioned actions. You can go to next temperature programming by pressing “SELECT” button. The Thermostat will go into start mode after you finish with programming of all temperatures from 2.1 – 2.6 and the new adjusted values will become current. After the adjustment of temperature 2.6 you can return to 4.1 (Inspection of water heater and solar panel temperatures) by pressing “SELECT” button.

For quick change of selected value – hold the “SELECT” button.

Emergency alerts

Indication Alarm

The light indication Alarm will be activated in the following cases:

When the water heater temperature exceeds Tbmax.
When the temperature of the solar panel is above Tpmax or bellow Tpdefros, in case a defrost mode is allowed.

The solar panel and water heater temperatures are out of preliminary fixed ranges:

When one of the temperatures is grater than +120°C on the digital display is being indicated “Hi”.
When one of the temperatures is lower than -20°C on the digital display is being indicated “Lo”

Wiring

The wiring comprises the connection of temperature sensors, a power supply and the circulation pump according Figure 2. The sensors are Pt1000 – non polar. If necessary, the length of connection cables can be prolonged, considering the total resistance of both cables, concerning indication sensibility of 1°С/4Ω. The recommended cable length which do not affect to measurement precision is up to 100m.

Terminals 7 and 8 are input for Pt1000 solar panel sensor.
Terminals 9 and 10 are input for Pt1000 water tank sensor
To terminals 1 and 2 are to be connected respectively phase and neutral from the power supply.
The pump is to be connected to terminal 3 and 4, which are respectively neutral and phase.

Caution!: In order to discharge the static electricity which could appear on the solar panels as well their metal supports a ground connection is to be provided. Otherwse, there is dangerous of damage concerning the sensors even of the controller.

Terminals 5 and 6 are an independent contact which provides start/stop signal to the electrical heating elements.

Hydraulic connections

Domestic hot water preparation only by solar panels
Domestic hot water preparation by means of solar panels and electrical heating elements of the water tank. РТ – water tank operation thermostat
БТ – water tank emergency (blocking) thermostat.
Domestic hot water preparation only by means of a stove and a magnetic ON/OFF valve, installed at the water tank.
Domestic hot water preparation by means of a stove and electrical heating elements of the water tank. РТ – water tank operation thermostat
БТ – water tank emergency (blocking) thermostat.

Technical data

Warranty

The warranty period is 24 months following the purchase date of the unit or its installation by an authorized Engineering Company, but not exceeding 28 months after the production date. The warranty is extended to the malfunctions that occur during the warranty period and are result of the production reasons or defective used parts.
The warranty does not relate to malfunctions corresponding to not-qualified installation, activities directed to the product body interference, not regular storage or transport.
The repairs during the warranty period can be done after correct filling of the manufacturer warranty card