Intiel TD-3.3 User manual

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INTIEL
THE ELECTRONICS ON YOUR SIDE
Programmable Differential Thermostat
TD-3.3
User’s Manual

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І. Application
Differential Thermostat DT-3.3 is used for a domestic hot water preparation, where the
heating of the water tanks is provided in a combined way, by solar panels and electrical
heating elements. It is designed to control the operation of one or two circulation pumps,
installed in the water circuit between the solar panels and water tank serpentine, thus
regulating the heat exchanging between them.
II. Functionality
DT-3.3 has an ability to control two main types of installations for a domestic hot water
preparation by means of solar or heating systems depends on the selected program.
2.1 Systems equipped with one water tank (default program) – the differential
thermostat follows the temperature of the solar panel (T1), the temperature of the lowest part
of the water tank (T2) and the temperature of the upper part of the water tank (T3).
2.2 Systems equipped with two water tanks – the differential thermostats follows the
solar panel temperature (T1), the temperature of the lowest part of water tank 1 (T2) and the
temperature of lowest part of water tank 2 (T3). The heating of water tank 1 is with a higher
priority than water tank 2
III. Operation
The Thermostat is equipped with three temperature sensors, mounted respectively at the
water tank (tanks) and at the solar panels. During its operation the thermostat monitors the
following parameters:
3.1. dT, ∆t – adjusted and current (real) difference between the water tank and solar
panel temperatures. dТcan be adjusted in the range of 2 up to 20°С. The default
setting is 10°С
3.2. Tzad (W) – assigned temperature level of the water tank to which it can be heated
from the solar panels. The temperature can be adjusted in the range between 30 and
80°С. The default setting is 60°С.
3.3. Tzad1(W1) –assigned temperature in the second water tank in systems with 2 water
tanks or an assigned temperature at the upper part with systems with one water tank.
The default setting is 60°С.
3.4. Tbmax – critical maximum allowed water tank temperature. It can be adjusted in the
range between 80 and 100 °С. The default setting is 90°С.
3.5. Tbmin – minimum water tank temperature bellow which the solar panel defrosting is
being stopped. It cannot be adjusted. The default setting is 20°С.
3.6. Tcmin – minimum temperature level of the solar panel. It can be adjusted in the
range between 25 and 50 °С. The default setting is 40°С.
3.7. Tcmax – maximum allowed temperature of the solar panel. It can be adjusted in the
range between 90 and 110°С. The default setting is 110°С.
3.8. Tdef – defrost temperature level of the solar panel. It can be fixed in the range
between (-20) up to (+10)°С. The default setting disables this function “- -“.
3.9. Tvmax – maximum allowed water tank temperature at which an emergency
drainage of the water tank can be started by means of relay output 3. It can be adjusted
in the range between 50 and 95°С. The default setting is 95°С.
- 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”

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Differential Thermostat DT-3.3 operation depends on the temperature sensor states, as
follows:
Installations equipped with one water tank
А)Normal operation
The circulation pump is being switched on and the water tank heating is being started if
the temperature at the lowest part of the water tank is lower than Tzad and there is a positive
difference ∆t between the solar panel and lowest part or the water tank temperature, grater
than the assigned one dТ(Т1-Т2> dТ). The circulation pump is being stopped (relay output
1) if during water tank heating ∆tis being decreased, thus after ∆tgets equalized with the
assigned one dT
The heating of the water tank at the above mentioned conditions is going until the water
tank temperature at its lowest part is getting the same with the assigned one Tzad. Afterwards
the pump is being switched off and the heating is being stopped.
If under the above mentioned conditions the solar panel temperature is going down
bellow Tcmin, then the circulation pump operation will be stopped by force, despite of
conditions ∆t>dТиТ2<Tzad could be available.
In case the solar panel temperature falls bellow Tdef, the circulation pump is being
switched on by force, never mind it has been switched off due to solar panel temperature
decreasing bellow Tcmin. (only in case the defrost option is activated)
If during the previous mentioned operation mode the water tank temperature falls down
bellow Tbmin, then the circulation pump is being switched off as the solar panel defrosting is
being stopped.
If the water tank temperature at its upper part T3 is lower than the assigned one Tzad1,
then the electrical heating elements operation is being allowed until Tzad1 is being reached.
(relay output 2), but only in case there are no conditions for circulation pump operation.
В) Emergency operation
If during water tank heating, the solar panel temperature exceeds Tcmax, the circulation
pump is being started by force in order to cool the solar panel. The previous mentioned will
be fulfilled despite of the water tank temperature at its lowest part T2 could exceeded Tzad
(relay output 1).
If during the above mentioned emergency mode the water tank temperature at its lowest
part reaches the critical maximum value Tbmax, then the circulation pump is being switched
off never mind it could reflect to solar panel overheating. Thus the water tank temperature has
a higher priority than the solar panel one.
When the water tank temperature at its upper part T3 exceeds Tvmax a valve is being
switched on in order to drain the hot water of the water tank (relay output 3).
Installations equipped with two water tanks
А)Normal operation
- The circulation pump 1 is being switched on and the heating of the water tank is being
started by means of the solar panels if temperature T2 in water tank 1 is lower than the
assigned one Tzad and if there is a positive difference ∆tbetween the solar panel and the
water tank temperatures grater than the assigned dТ(Т1-Т2> dТ), The circulation pump is
being stopped if during water tank heating ∆tis being decreased, thus after ∆tgets equalized
with the assigned one dT.
The heating of the water tank at the above mentioned conditions is going until the water
tank temperature is getting the same with the assigned one Tzad. Afterwards the pump is
being switched off and the heating is being stopped (relay output 1).

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- when water tank 1 reaches its assigned temperature, then the operation of circulation
pump 1 is being stopped and the heating of the second water tank is being started as
circulation pump 2 is being switched on. In this case circulation pump 2 will be started in case
temperature T3 in water tank 2 is lower than Tzad1 and there is a positive difference ∆t
between solar panel and water tank, grater than the assigned one temperatures dТ(Т1-
Т3>dT) (relay output 1 and 2).
- the operation of circulation pump 2 is being stopped in case of reaching Tzad1,
equalizing ∆t with dТor with decreasing of T2 concerning water tank 1 bellow Tzad. In the
last case after circulation pump 2 is being switched off circulation pump 1 is being switched
on for heating of water tank 1.
- If under the above mentioned conditions the solar panel temperature is going down
bellow Tcmin, then both circulation pumps operation will be stopped by force, despite of
conditions ∆t>dТand Т2<Tzad, Т3<Тzad1 could be available. (relay output 1 and 2)
- in case the solar panel temperature falls bellow Tdef, circulation pump 1 is being
switched on by force, never mind it has been switched off due to solar panel temperature
decreasing bellow Tcmin. (only in case the defrost option is activated)
- if during the previous mentioned operation mode water tank 1 temperature falls down
bellow Tbmin, then the circulation pump is being switched off as the solar panel defrosting is
being stopped.
В) Emergency operation
- if during water tanks heating, the solar panel temperature exceeds Tcmax, the circulation
pumps are being started by force in order to cool the solar panel. The previous mentioned will
be fulfilled despite of temperatures T2 and T3 of the water tanks could exceed Tzad and
Tzad1 (relay output 1 and 2).
- if during the above mentioned emergency mode the water tank temperatures reach the
critical maximum value Tbmax, then the circulation pumps are being switched off never
mind it could reflect to solar panel overheating. Thus the water tank temperature has a higher
priority than the solar panel one.
- when temperature T3 in water tank 2 exceeds Tvmax a valve is being switched on in
order to drain the hot water of the water tank (relay output 3).
ІV. Front panel indications
On the front panel are located the control elements and programming. These are two line
LCD display, seven light indications and three buttons, “SELECT”, “SCROLL” and ”SET”.
The front panel vision is shown at Figure 1 bellow.
4.1 Light indication 1 – shows the operation of circulation pump 1
4.2 Light indication 2 - shows the operation of circulation pump 2 (in case two water tanks
are installed) or heating of the water tank by means of electrical heating elements.
4.3 Light indication 3 – shows switched on valve for hot water draining.
4.4 Light indication 4 – shows emergency situation with the solar panel, for example a
maximum solar panel temperature is being reached or a defrost protection is activated.
4.5 Light indication 5 – show an emergency situation, the temperature in water tank 1 has
being reached the maximum allowed water tank temperature Tbmax.
4.6 Light indication 6 – show an emergency situation, the temperature in water tank 2 has
being reached the maximum allowed water tank temperature Tbmax.
4.7. Light indication 7 – shows that the unit is in a setting mode
After connection of the power supply the thermostat goes into an initial mode as it shows
the solar panel and water tank/tanks temperatures.

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V. Programming
5.1 Entering the thermostat menu
Entering the thermostat menu could be done by pressing and keeping “SET” button for
more than 3 sec. The main menu consists of two submenus – “Settings” and “Options”.
Switching between them can be done by pressing “SCROLL” button. To enter and escape
each of the submenus “SELECT” button is to be pressed. Returning to the operation mode can
be done automatically in 25 seconds (during which any button is not being pressed) or from
the main menu after pressing “SET” button.
5.2 Submenu “Settings”
After entering submenu “Settings”, by pressing “SELECT” button it can be seen all
parameters (mentioned at point 3), which the thermostat follows and their relevant values. The
switching between them can be provided by pressing “SCROLL” button. The value of each
parameter can be changed by pressing “SET” button, as light indication 7 (Х=?) is being
activated and buttons “SELECT” and “SCROLL” change their functions as their relevant new
meaning is “up and down arrow”. After the desired value is being selected, the “SET” button
is to be pressed again in order to save it and the light indication 7 is being deactivated.
5.3 Submenu “Options”
At that menu it could be selected the type of the system with which the thermostat will
work, in systems with one or two water tanks, and whether the solar panel defrost function is
to be activated or not. By means of “SCROLL” button the relevant option is being selected as
with “SET” button it could be changed.
One water tank Two water tanks Anti-freezing protection

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VI. Wiring
The wiring of the thermostat includes connection of the temperature sensors, power supply,
controlled circulation pump, electrical heating elements and a valve according Figure 3. The
temperature sensors are Pt-1000 non-polar ones. In case of necessity the connection cables of
the sensors could be prolonged as the total resistance of both cores of the cable will be
observed – an indication sensibility of 1°С/4Ω. The recommended cable length which does
not affect the measurement
precision is up to 100m.
Terminals 3 and 4 are inputs for
solar panel temperature sensor T1.
Pt-1000 sensor is to be connected
to those terminals.
Terminals 5 and 6 are inputs for
water tank 1 temperature sensor T2.
Pt-1000 sensor is to be connected
to those terminals.
Terminals 7 and 8 are inputs for
water tank1/water tank2
temperature sensors T3. Pt-1000
sensor is to be connected to those
terminals.
To terminals 44, 48 and 52 are
to be connected a phase, neutral and protection ground of the grid.
To terminals 38, 40 and 42 are to be connected respectively circulation pump 1, circulation
pump 2/electrical heating elements and a valve.
A phase (L1) appears at terminals 37, 39 and 41, when it does not at terminals 38, 40 and
42, and an opposite.
VII. Hydraulic connections
A) Systems equipped with one water tank. The water tank heating is provided by means
of solar panel and electrical heating elements

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БТ – blocking thermostat
РT – operation thermostat
B) Systems equipped with two water tanks. The water tank heating is provided by
means of solar panels.
Technical data
Supply voltage: 230V / АС / 50-60Hz
Maximal rated current: 7А/ 250V / AC / 50-60Hz
Outputs: 3 standard relays (changeover contacts)
Switch-on difference: ∆T 2…200Сadjustable
Sensors: 3 temperature sensors Pt1000 (-50° до +200°C)
Sensor current: 2.6 mA
Range of temperature measuring: from -20 up to +1200С
Digital display: Two lines LCD
Measurement precision: 1°С
Humidity: 0-80%
Protection: IP20

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Parameters
Indications Describtion Temperature
Range Default settings Clients’ settingsа
dT
Assigned temperature difference
between the solar panel and the
water tank 2 ÷ 20°С10° С
Tzad
(W)
Assigned temperature until which
the water tank can be heated by
means of the solar panels
30 ÷ 80° С60° С
Tzad1
(W1)
Assigned temperature in second
water tank with two water tanks
systems and assigned temperature
at the upper water tank part with
systems with one water tank
30 ÷ 80°С60° С
Tbmax Maximum allowed water tank
temperature. 80 ÷ 100°С90° С
Tbmin
Minimum water tank temperature
bellow which the solar panel anti-
freezing is being stopped.
не се задава 20° С
Tcmax Maximum allowed solar panel
temperature. 90 ÷ 110°С110° С
Tdef
Solar panel temperature level at
which the ant-freezing protection
is being activated. -20 ÷ 10°С-20° С
OFF
Tvmax
Maximum water tank temperature
at which the relay output 3 is
being activated. 50 ÷ 95°С95° С
VІ. 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
Warranty Card
Manufacturer: INTIEL
P
roduct t
yp
e Programmable Differential Thermostat DT-3.3
P
roduction numbe
r
P
roduction date
Dealer confirmation
P
urchase date
Invoic
e
number
D
eale
r
’s name, address
and stamp
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eller’s name and
signature