Tech Controllers ST-81 User manual

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User’s manual
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Declaration of Conformity for Controllers
ST-81 No 23/2007
The product was marked with CE for the first time: on July 4, 2007.
The company TECH, based in Wieprz 1047A, 34-122 Wieprz,
declares with complete liability that the temperature regulator ST-81
230V, 50Hz meets the requirements of the Regulation of the Minister of
Economy, Labor and Social Policy (Journal of Laws No 155, item 1,089)
dated August 21, 2007, implementing the provisions of the Low Voltage
Directive (LVD) 2006/95/EC, the Act dated April 13, 2007 on
electromagnetic compatibility (Journal of Laws 07.82.556) implementing
the provisions of Directive (EMC) 2004/108/EC, as well as the Regulation
of the Minister of Economy dated May 8, 2013 "on basic requirements on
the restriction of the use of certain hazardous substances in electrical and
electronic equipment" implementing the provisions of Directive ROHS
2011/65/EU.
Harmonized standards were used to assess the conformity PN-EN
60730-2-9:2011, PN-EN 60730-1:2012.
Wieprz, 30. 01. 2015

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I. Safety
Before using the device for the first time the user should read the following regulations carefully. Not
obeying the rules included in this manual may lead to personal injuries and device damage. This
manual should be stored carefully.
In order to avoid unnecessary errors and accidents it should be ensured that every person using the
device has familiarized themselves with the principle of operation as well as security functions of the
device. If the device is to be sold or put in a different place, make sure that the user's manual is there
with the device so that any potential user has access to essential information about the device. The
manufacturer does not accept responsibility for any injuries or damage resulting from negligence;
therefore, users are obliged to take the necessary safety measures listed in this manual to protect
their lives and property.
WARNING
High voltage! Make sure the regulator is disconnected from the mains before performing any
activities involving the power supply (plugging cables, installing the device etc.)
The device should be installed by a qualified electrician.
Before starting the controller, the user should measure the earthing resistance of the electric
motors as well as the insulation resistance of the cables.
The regulator should not be operated by children.
NOTE
The controller may be damaged by lightning. Make sure the plug is disconnected from the
power supply during storms.
Any use other than that specified by the manufacturer is forbidden.
Before and during the heating season, the controller should be checked for the condition of its
cables. The user should also check if the controller is properly mounted and clean it if dusty or
dirty.
Changes in the merchandise described in the manual may have been introduced subsequent to its
completion on February 2th 2015. The manufacturer retains the right to introduce changes to the
structure. The illustrations may include additional equipment. Print technology may result in
differences in colours shown.
Care for the natural environment is our priority. Being aware of the fact that we
manufacture electronic devices obligates us dispose of used elements and electronic
equipment in a manner which is safe for nature. As a result, the company has
received a registry number assigned by the Main Inspector of Environmental
Protection. The symbol of a crossed out rubbish bin on a product means that the
product must not be thrown out to ordinary waste bins. By segregating waste
intended for recycling, we help protect the natural environment. It is the user's
responsibility to transfer waste electrical and electronic equipment to the selected
collection point for recycling of waste generated from electronic and electrical
equipment.

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II. Principle of Operation
The ST-81 temperature regulator is intended for central heating boilers. It controls the CH water
circulation pump, the hot water (DHW) pump and the airflow (the fan).
If the boiler temperature is lower than the pre-set temperature, the regulator enters its
operation cycle in which the airflow operates continuously.
If the boiler temperature is equal to, or higher than the pre-set temperature, the regulator is
in the support cycle and the controller operates by activating blow-throughs at a frequency dependent
on the user's settings. The blow-through operation and pause time in support should be selected in
accordance to the type of fuel combusted in the boiler.
TECH uses one manual for the ST-81 controller in various program versions, depending on the
boiler type. The program's version is written individually for each boiler's manufacturer. Any comments
regarding the program should be reported to the boiler's manufacturer.
Each controller should be set individually for the user's own needs, depending on the type of fuel used
for burning, as well as the boiler type. TECH does not accept responsibility for incorrect use of settings
for the controller.
III. Installation
The controller should be installed by a qualified person.
WARNING
Risk of fatal shock from touching live connections. Before installing the regulator, switch off the power
supply and prevent it from being switched on accidentally.
NOTE
Incorrect connection of cables may damage the regulator!
The ST-81 controller needs to be connected to the boiler during installation so that there is no
external access to the cable installation strip.
The rear part of the controller contains couplings to which the sensors as well as devices operated by
the controller should be connected:

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General Diagram - the diagram does not replace the design of a CH system. It is intended for the
demonstration of the controller's expansion possibility. The presented diagram of the heating system
does not contain elements cutting-off and protecting for the execution of professional installation.
Location of the Thermal Overload Relay and the Boiler's Sensor:
The thermal overload relay is a bimetallic sensor located next to the boiler's temperature sensor in
the capillary or on the pipe feeding the CH circulation as close to the boiler as possible.
Installation in the boiler's capillary.
Installation on the feed of CH circulation.

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IV. Operating the Controller
1. PLUS Button - changing the pre-set temperature from the main screen view, after entering the
controller's menu the button is used to increase the work settings.
2. MINUS Button - changing the pre-set temperature from the main screen view, after entering
the controller's menu the button is used to decrease the work settings.
3. Entering the controller's menu, approving settings.
4. Mains switch.
5. Exiting the controller's menu, cancelling settings.
6. Diode signaling manual operation.
7. Diode signaling operation of DHW pump
8. Diode signaling operation of CH pump
9. Diode signaling fan operation.
Changing the Settings of Pre-Set CH and DHW Temperatures
During regular operation of the regulator, the LCD displays the
main page with the following information: current temperature
of the boiler as well as the pre-set temperature.
This screen enables the user to quickly change the pre-set CH
temperature with the use of PLUS and MINUS buttons.
In order to change the setting of the pre-set DHW temperature,
the user should press and hold the button EXIT and then mark
the option DHW screen. The display will show the DHW screen
which enables the user to change the setting of pre-set DHW
temperature with the use of PLUS or MINUS buttons.
Pressing the OPTIONS button moves the user to the menu. Use PLUS and MINUS buttons to move
around the menu. After marking the appropriate function, the user should confirm it by using the
OPTIONS button (this button is also used to approve changed parameters). Pressing the EXIT button
enables the user to leave the selected function (to the main screen view) or cancel the setting.
1
2
3
4
5
6
7
8
9
25⁰C 59C
CH Pre-set
CH screen
DHW screen

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V. Regulator Functions – Main Menu
Due to the multifunctional nature of the controller, the menu is divided into the Main Menu and the
Servicing Menu. The user sets basic working parameters in the Main Menu: pre-set temperatures,
modes of operation etc. This is illustrated by the diagram below:
V.a) Firing-Up
After the initial lighting up of the fire source in the boiler, the user should activate the firing-up function.
The fan will begin to operate in this mode in order to facilitate the firing-up (on a boiler which is not
yet heated). When the CH temperature increases to 30°C (the so-called fan threshold), the display
will show ‘Switch Fan On/Off’ instead of ‘Firing-Up’, the diode manual operation will go out and the
boiler will proceed to its operation mode. Using the ‘Switch Fan On/Off’ function, the user may switch
the airflow on or off (e.g. when adding fuel). Switching the fan off is signalled with the sign of a star
on the main screen in the display's bottom right-hand corner. This function enables the user to safely
operate the boiler. Opening the doors of the furnace with the fan switched on is forbidden.
If the boiler reaches a temperature of 35°C, the pump activates (or both pumps, depending on the
operation mode).
V.b) Manual Operation
For the user's convenience, the regulator is equipped with the
ability to be set to Manual Operation where each executive
element is switched on and off independently of the others.
Pressing the OPTIONS button activates the engine of a selected
device (or alarm) which remains activated until the OPTIONS
button is pressed again.
Main Menu
Firing-Up
Manual Operation
Airflow Power
Fan
CH Pump
DHW Pump
Alarm
Airflow Power
Operation in Support
Pause in Support
Blow-Through Power
Boiler Hysteresis
DHW Hysteresis
CH Pump Activation
DHW Pump Activation
Operation Mode
House Heating
DHW Priority
Parallel Pumps
Summer Mode
Room Regulator
Language
Factory Settings
Airflow power
Fan
CH pump
DHW pump

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The Airflow Power, where the user has the option to define any
rotational speed of the fan in manual operation, is additionally
available.
V.c) Airflow Power
This function controls the speed of fan operation. The
regulation range varies depending on the program (from 1 to
6 or from 1% to 100%), and it may be assumed that these are
the fan's gears - the higher the gear, the faster the fan is
operating.
Any changes in the fan's gears are made with the use of the PLUS and MINUS buttons. Depending
on the program's version, the fan is initially activated with full speed and slows down to the pre-set
gear or starts from a low gear and then proceeds to the pre-set gear.
V.d) Operation in Support
This option is used to set the time of airflow operation during
support, namely after the boiler reaches the pre-set
temperature (or is above the pre-set temperature).
V.e) Pause in Support
This option is used to set the time of pause in airflow operation
during support (after the boiler reaches the pre-set CH
temperature).
V.f) Blow-Through Power
This option enables the user to set the fan's airflow power in
support.
NOTE
The functions included in these three points of the menu are used to regulate the boiler's operation
when in the support cycle. It prevents the boiler from going out as well as hampers the further growth
in temperature when the boiler temperature remains above the pre-set temperature.
NOTE
Incorrect setting of the options contained here may result in a constant temperature increase! In
particular, pause in support should not be too short, and operation in support should not be too long.
NOTE
The star (*) on the main screen means that the fan is switched on. In this case, the function operation
and pause in support is inactive. In order for all functions to be active, the user should switch the fan
on using the ‘Fan Switch On/Switch Off’ function (see: point V.a).
Alarm
80 %
Airflow power
20 seconds
Operat In support
30 minutes
Pause in support
80 %
Blow-through pow

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V.g) CH Hysteresis (of the boiler)
This option is used to define the hysteresis of pre-set
temperature. It is the difference between the temperature of
entering into the support cycle, and the temperature when
returning to the operation cycle (e.g. if the pre-set temperature
is 60°C and the hysteresis is 2°C, the support cycle is activated
when the temperature of 60°C is reached, and the operation cycle is activated again when the
temperature drops to 58°C). Hysteresis may be defined depending on the program in the maximum
range from 1°C to 20°C.
V.h) DHW Hysteresis
This option is used to define the hysteresis of the pre-set
temperature of the boiler. It is the difference between the pre-
set temperature (namely temperature desired on the boiler
when the DHW pump stops operating) and the temperature of
activating the DHW pump again (e.g. if the pre-set DHW
temperature is 55°C and the hysteresis is 5°C, the DHW pump is deactivated after reaching the pre-
set temperature, namely 55°C. The DHW pump is activated again when the boiler's temperature drops
to 50°C).
V.i) CH Pump Activation
This option is used to set the threshold temperature of CH
pump activation (it is the temperature measured on the boiler
display). Below this value the pump is inactive, whereas above
this value the pump is active.
V.j) DHW Pump Activation
This option is used to define the threshold temperature of DHW
Pumps activation (it is the temperature measured on the boiler
display). Below this value the pump is inactive, whereas above
this value the pump is active, but operates depending on the
operation mode (house heating, boiler priority, parallel pumps,
summer mode).
V.k) Modes of Operation
In this function, the user selects one of four options of the boiler's operation. The star next to one of
the operation modes (*) means that the boiler is in this mode.
V.k.1) House Heating
By selecting this option, the regulator switches to house
heating only. The CH pump starts to operate above the pump
activation threshold (pre-set at 35°C). Below this temperature,
the pump stops operating (minus hysteresis). In this mode,
the main screen, next to the temperatures on the right-hand
side of the display, shows the following symbol .
V.k.2) DHW Priority
Activating this function makes the regulator switch into boiler priority mode. In this mode, the boiler
pump is switched on (DHW) until the pre-set DHW temperature is reached. After reaching the boiler
pre-set temperature, the DHW pump switches off and the CH pump starts operating. The CH pump
operates constantly until the temperature on the boiler drops below the pre-set temperature (and
DHW hysteresis). Then, the CH pump is switched on and the DHW pump is activated.
2⁰C
Boiler hysteresis
5⁰C
DHW hysteresis
30⁰C
Switch CH pump on
House heating
DHW priority
38⁰C
Switch DHWpump on

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In this mode, when the boiler is still insufficiently heated, the fan's operation is limited to a
temperature of 62°C on the boiler because this prevents the boiler from overheating.
The DHW priority function consists in heating first the hot utility water and then heating up the water
in the radiators.
In this mode, the main screen, next to the temperatures on the right-hand side of the display, shows
the symbol
NOTE
The boiler should be equipped with return valves on the circulations of CH and DHW pumps. The valve
fitted on the DHW pumps prevents hot water from being sucked out of the boiler. The valve fitted to
the circulation of the CH pump never lets through hot water which heats the boiler to the house.
V.k.3) Parallel Pumps
In this mode, the pumps' operation starts simultaneously
below the pre-set temperature (see, Function Pump Activation
Temperature). The CH Pump operates continuously, and the
DHW Pump is switched off after reaching the pre-set
temperature on the boiler. In this mode, on the main screen
next to the temperatures on the right-hand side of the display, shows the symbol .
V.k.4) Summer Mode
After activating this function, the CH pump is switched off and
the DHW pump is switched on above the pump activation
threshold. After exceeding the threshold temperature, the
DHW pump operates continuously until the boiler temperature
drops below the pump activation threshold (by the DHW
hysteresis value). In the summer mode, only the pre-set temperature of the boiler is defined,
additionally operates as the boiler's pre-set value. After activating the summer mode, the main screen
will show the symbol *.
V.l) Room Regulator
The room regulator is connected to the controller with the use
of a two-core cable via the connection socket marked as ROOM
REGULATOR. After the correct connection with the boiler
controller, the user should activate its activity in the controller's
menu.
The principle of the room regulator's operation is based on disconnecting the contacts of cables
leading to it when the pre-set temperature in the room is reached. If the boiler's controller receives a
signal about room heat-up, it automatically proceeds to the support mode, regardless of the boiler's
pre-set temperature.
Note. If the pre-set temperature on the controller fitted on the boiler is too low, the room regulator
may not reach the pre-set temperature in the apartment.
After activating the option Room Regulator with the boiler's controller, the main screen in the
upper part of the display will show the letter<p>If the letter is pulsating, this proves that the room is
heated insufficiently (the room's regulator pre-set temperature is not reached). When<p>is displayed
continuously, the pre-set room temperature has been reached (heated room).
NOTE
No external power supply may be connected to the room regulator's input.
V.m) Language *
In this function, the user may change the language version of
the controller's software.
* Function active in certain software versions.
Parallel pumps
Summer mode
Parallel pumps
Summer mode
Operat mode
Room regulat.
Polski
English