Tech Controllers EU-81zPID User manual

User’s manual
EU-81zPID

EU-81zPID
2
TECH
Declaration of Conformity No. 23/2007
Hereby, we declare under sole responsibility that the ST-81 230V
50Hz thermoregulator manufactured by TECH, Wieprz 1047A, 34-
122 Wieprz, is compliant with the Regulation by the Ministry of
Economy. (Journal of Laws Dz.U. 155 Item 1089) of July 21, 2007
implementing provisions of the Low Voltage Directive (LVD)
2006/95/EC of January 16, 2007.
The ST-81 controller has been tested for electromagnetic
compatibility (EMC) with optimal loads applied.
For compliance assessment, harmonized standards were used:
PN-EN 60730-2-9:2006.
Co-owners:
Paweł Jura, Janusz Master

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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 or controller damage. The user’s
manual should be stored in a safe place for further reference. In order to avoid accidents and errors 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 controller. 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 shoud measure earthing resistance of the electric
motors as well as the insulation resistance of the cables.
The regulator should not be operated by children.
WARNING
The device may be damaged if struck by a lightning. Make sure the plug is disconnected
from the power supply during storm.
Any use other than specified by the manufacturer is forbidden.
Before and during the heating season, the controller should be checked for condition of
its cables. The user should also check if the controller is properly mounted and clean it if
dusty or dirty.
!
!

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II. Description
The EU–81zPID temperature regulator is intended for use with central heating boilers. The regulator is
used for controlling the central heating water circulation pump, hot consumption water pump and blow
(fan).
The ST-81zPID is a PID-basedcontroller using a continuous signal. In this type of controllers,
the fan power is calculated based on boiler temperature and flue gas temperature measured at the boiler
outlet. The fan runs continuously and its power depends directly on the measured boiler temperature
and flue gas temperature as well as the difference between the two parameters and their setpoint values.
Advantages of zPID regulators include their ability to maintain a stable setpoint temperature without
unnecessary overregulations and oscillations.
By fitting the controller with a flue gas outlet sensor, you can save from a few up to several
percent of fuel, and ensure a steady water temperature for a longer service life of your heat exchanger
(boiler). Flue gas outlet temperature monitoring ensures reduced harmful dust and gas emissions. The
thermal energy from the flue gases is used for heating instead of being wasted and disposed of through
the funnel.
Research results presented below were obtained using the Tech PID-based controller:
Blow
C.H.
Pump
H.C.W.
Pump
Manual
Mode
Enter main
menu, confirm
PLUS
button
Return from
menu, resetting
MINUS
button
Power
switch

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and the controller without PID control:
In each case, the software version is customized to the furnace manufacturer’s requirements.
Please send all comments on the software to the boiler manufacturer.
Your controller should be set according to your individual needs, depending on the type of fuel and boiler
used. TECH shall not be held responsible for incorrect settings.
II.a) Basic Terms
Fire up. The cycle begins when you activate the fire up function in the controller's menu and is active
until the central heating boiler temperature reaches 40oC (the default fire-up threshold), on condition
that the temperature does not drop below this value for 2 minutes (the default fire-up time). If these
conditions are met, the regulator will switch to the duty mode and the manual operation symbol on the
housing will be deactivated. If the controller fails to reach parameters required for entering into the duty
mode within 30 minutes from activation of the fire-up function, the "Unable to fire up" message will
appear on the display. In such a case, the fire-up cycle needs to be restarted.
Duty –once the fire-up cycle is finished, the controller enters the duty cycle. The duty cycle is the basic
functionality of the regulator. The blow is controlled automatically using the zPID algorithm and the
temperature is close to its setpoint value. In the user menu, fan item will appear in place of the fire-up
function. The fan can be deactivated when needed (e.g. while feeding fuel). If the temperature rises
unexpectedly by more than 5oC over the setpoint value, the so-called Supervision Mode is activated.
Supervision Mode –the mode is activated during the Duty Cycle if the temperature rises by more than
5oC over the setpoint value. In such case, the controller is switched from the PID control to manual
settings (according to parameters entered in the Fitter’s Menu) to reduce the temperature of the
circulation water.
Damping –if boiler temperature drops by 2oC below the fire-up threshold and fails to rise above this
value for 30 minutes (default damping time), the regulator will switch to thedamping mode. While in this
mode, the fan is deactivated and the display shows "Damping".
III. Regulator Functionality
This chapter describes regulator functionality, how to change settings and navigate in the menu with the
buttons. Depending on the mode the boiler is currently in, the display will show boiler operational
parameters. The given mode is selected by the user.

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III.a) Main Page
During normal operation, the LCD display shows the Main Page containing the following:
Boiler temperature (to the left of the display).
Setpoint temperature (to the right of the display).
Fan stop. After manually stopping the fan while in the duty mode, the star symbol ( ) will appear
in the up right corner.
Operation Mode. In the up right corner, the corresponding letter of the operation mode is
displayed. Depending on the operation mode, the corresponding symbol is displayed:
–house heating, –water heater priority,
–parallel pumps, –summer mode.
In order to check the flue gas outlet temperature, press EXIT (hold for several seconds) until the
following screen is displayed:
The left of the screen shows the boiler temperature; the middle of the screen shows the flue gas
outlet temperature; the right of the screen shows the power of the fan. Press EXIT to return to the main
menu.
ST-81 thermal controller is designed for central heating boilers. ST-81 thermoregulator is designed
for wood-fired central heating boilers. It controls water circulating pump and air injection (fan). However,
this type of controller cannot control rotation of the fan.
Pressing the MENU button will move you to the main menu. The display shows two options of the
menu. To select a different option, press PLUS or MINUS button.
III.b) Changing the central heating and hot consumption water
setpoint temperature.
In order to change the setpoint temperature of the central heating (while in "C.H. screen" main
view), press PLUS or MINUS button and (after setting a desired value) press MENU to confirm the change.
In order to change the setpoint temperature of the hot consumption water (while in "H.C.W.
screen" main view), press PLUS or MINUS button and (after setting a desired value) press MENU to
confirm the change.
Chapter "Screen" describes methods of changing the main screen view.
23 Oc 26 Oc 1%

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III.c) Firing up/Fan
This function allows you to easily fire up the boiler. After igniting the boiler, you need to activate
an automatic fire-up cycle. By selecting optimum parameters, the boiler uses the zPID function to
smoothly switch to the duty mode. If the boiler reaches the fire-up threshold temperature, the fan item
will appear instead of the fire-up function. From now on, the option will be used to activate/deactivate
the fan. This setting allows you to temporarily deactivate the fan at any time, e.g. while feeding fuel.
If during the fire-up cycle the boiler does not reach 40OCwithin 30 minutes, (default parameters), the
following warning message will appear on the display:
To restore the boiler to operation, switch off the alarm by pressing the button MENU and restarting the
fire-up procedure.
III.d) Manual Mode
For your convenience, the regulator features a manual mode module. In this mode, each individual
actuator is enabled and disabled independently of the other. In addition to the Manual Mode function,
the Blow Force function has been provided.
This function allows you to set the blow force of the fan while in the Manual Mode.
Pressing MENU activates the fan. The fan will operate until button MENU is pressed again.
Press MENU to enable / disable the central heating pump.
Press MENU to enable / disable the (water heater) hot consumption water pump.
Press MENU to enable / disable the alarm.

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III.e) Fuel Type
This option allows you to select one of three fuel types (coal, fines and wood) for use in the boiler. Each
fuel type has a fan operation mode assigned to ensure the right burning process.
III.f) Central Heating Pump Activation
With this function, you can set the temperature that will activate the central heating pump (the
temperature is measured on the boiler). The pump will start if the setpoint temperature is exceeded. The
pump will be deactivated when the boiler temperature drops below the activation temperature (minus
hysteresis, e.g. 2OC). In this case, the pump will stop at boiler temperature of 33OC.
III.g) H.C.W. Pump Activation
With this function, you can set the temperature that will activate the hot consumption water pump (the
temperature is measured on the boiler). Above the setpoint temperature (e.g. 40OC), the pump is
activated and operates depending on the selected operation mode. The pump will be deactivated when
the boiler temperature drops below the activation temperature (minus hysteresis, e.g. 3OC). In this case,
the pump will stop at boiler temperature of 37OC.
III.h) Operation Mode
With this function, you can select one out of four operation modes.
III.h.1) House Heating
If you select this option, the regulator will switch to the house heating mode. The central heating pump
starts to run above the pump activation temperature (set to 35OC by default). Below this temperature
(minus central heating hysteresis), the pump is shut off. While in the house heating mode, the icon is
displayed in the up right corner of the main screen.

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III.h.2) H.C.W. Priority
Activating the hot consumption water priority will cause the regulator to switch into the water heater
priority mode. In this mode, the (hot consumption water) heater pump is activated until the set H.C.W.
temperature is reached. Then, the H.C.W. pump is shut off and the C.H. pump is activated. The central
heating pump will run until the water heater temperature drops below the setpoint value (and the H.C.W.
hysteresis); then, the C.H. pump is shut off and the H.C.W. pump is activated.
In this mode, the fan is operated as long as the temperature is below 62°C to prevent the boiler from
overheating.
The hot consumption water priority function consists in that the consumption water is heated up before
heating up water in radiators.
While in the H.C.W. Priority mode, the icon is displayed in the up right corner of the main screen.
ATTENTION: The boiler should have non-return valves mounted on the central heating pump circuit and
the hot consumption water pump circuit. A valve mounted on the hot consumption water pump will
prevent hot consumption water from being drawn from the water heater.
III.h.3) Parallel Pumps
In this mode, the pumps start to run in parallel above the pump activation temperature (set by default
to 35OC). These temperatures may, however, vary depending on user settings. This will cause irregular
activation of the pumps. However, when both thresholds are exceeded, the pumps will operate
simultaneously. The central heating pump runs continuously, while the hot consumption water pump
stops after the setpoint temperature is reached in the water heater.
While in the Parallel Pumps mode, the icon is displayed in the up right corner of the main screen.
ATTENTION: In this mode, a non-return valve should be fitted to maintain different temperatures in the
water heater and in the house. After activation of the parallel pumps function, three items appear on the
display. Starting from the left, these are: Boiler Temperature (C.H.); Water Heater Temperature (H.C.W.)
and Setpoint Temperature (C.H.).
III.h.4) Summer Mode
When the function is enabled, only the hot consumption water pump is running in order to heat water in
the water heater. The pump is switched on above a predefined activation threshold (see the pump
activation temperature function) and will run until the setpoint temperature has been reached. The pump
will start again when the temperature drops below the set hysteresis. In the Summer Mode, only the
setpoint temperature is set on the boiler that heats up water for the water heater (the temperature set
for the boiler is also the temperature set for the water heater).
While in the Summer Mode, the icon is displayed in the up right corner of the main screen.

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III.i) Main Screen
This function allows you to change the view of the main screen. The following views are available:
C.H. SCREEN
This screen displays the current and setpoint C.H. temperatures. By pressing PLUS or MINUS
button, you can change the setpoint temperature. After setting the appropriate value, confirm it by
pressing MENU.
H.C.W. SCREEN
This screen displays the current and setpoint H.C.W. temperatures. By pressing PLUS or MINUS button,
you can change the setpoint H.C.W. temperature. After setting the appropriate value, confirm it by
pressing MENU.
FLUE GASES SCREEN
The following items are displayed, starting from the left: current C.H. temperature, current flue
gases temperature and blow power in percentages. This view is used for monitoring current boiler
parameters.
III.j) Language
With this function, you can select the language of your controller.
•
•
•

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III.k) Factory Settings
The regulator has been pre-configured. However, it should be adjusted to your individual needs. It is
possible to return to the factory settings at any time. By enabling the Factory Settings, all existing boiler
settings will be replaced by settings made by the manufacturer. From then on, you can again set your
own operating parameters for the boiler.
III.l) Fitting parameters
Access to fitting parameters is disabled for the user. This special view contains advanced
parameters accessible only by the manufacturer.
IV. Protections
In order to ensure a safe and faultless operation, the regulator has been provided with numerous
protections. In the case of an alarm, an acoustic warning is sounded and the display shows a
corresponding message.
Press MENU button to restore the controller to operation. In the case of the C.H. Temperature Too
High alarm, wait until the temperature drops below the alarm value.
IV.a) Thermal protection
The boiler is protected with an additional bimetal sensor (located at the boiler temperature sensor) that
disables the fan when the temperature exceeds the critical value: 85OC. This is to prevent water from
boiling in the system when the boiler has been overheated or the controller is damaged. When the
protective function is enabled and the temperature drops to a safe value, the sensor will automatically
restart the device and the alarm will be deactivated. If the sensor is damaged or overheated, the burner,
fan and feeder are disabled.
IV.b) Automatic Sensor Check
When the temperature sensor of the central heating or hot consumption water is damaged, an
alarm is sounded with an additional indication shown in the display, e.g.: „C.H. Sensor Damaged".
Blow is disabled and both pumps are activated simultaneously, regardless of the temperature.
If the central heating sensor is damaged, the alarm will remain active until the sensor is replaced. If the
hot consumption water sensor is damaged, pressMENU to deactivate the alarm and restore the single
(house heating) pump mode. To be able to operate the boiler in all modes, it is necessary to replace the
sensor.
IV.c) Temperature Protection
The regulator features an additional protection in case the bimetal sensor is damaged. After the
temperature exceeds 85OC, the alarm is sounded with the display showing the following message:

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The current temperature is read from an electronic sensor and processed by the thermoregulator. When
the alarm temperature is exceeded, the fan is shut off and both pumps begin to run in order to distribute
hot consumption water throughout the system.
IV.d) Anti-Boil Protection
This protective function is used only with the water heater priority mode. For example, when the water
heater setpoint temperature is 55OC and the boiler temperature rises to 67OC (5OC over the so-called
priority temperature), the controller shuts off the fan.If the boiler temperature reaches 80OC, the C.H.
pump will be activated. If the temperature continues to rise, the alarm will be activated at 85OC. Such
condition may appear when the water heater or the pump is damaged or when the sensor has been
improperly installed. However, if the temperature drops, the controller will activate the fan at 66OC and
it will remain in the duty mode maintaining the priority temperature of 62OC.
IV.e) Monitoring the flue gas outlet temperature
This sensor constantly monitors the flue gas outlet temperature. If the sensor is damaged, disconnected
from the controller or removed from the flue conduit, Flue Gas Sensor Damaged massage will appear
on the display. This will cause the controller to switch to the emergency mode. In such case, only boiler
temperature is used. The controller is operated using only the boiler sensor and the zPID function remains
active without the flue gas outlet sensor.
IV.f) Fuse
The regulator has a network protection WT 3.15 A tube fuse. Higher current ratings may cause damage
to the controller.
V. Maintenance
Before and during the heating season, the ST-81 controller should be checked for condition of its cables.
You should also check if the controller is properly mounted and clean it if dusty or dirty. It is advisable to
measure grounding parameters for the motors (central heating pump, hot consumption water pump and
fan)

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ST-81 Technical Specifications
No.
Specification
Unit
1
Supply Voltage
V
230V/50Hz +/-10%
2
Power consumption
W
5
3
Ambient temperature
OC
5÷50
4
5
Circulation pump outlet load
Fan outlet load
A
A
0,5
0,6
6
Temperature measurement range
OC
0÷90
7
Measurement accuracy
OC
1
8
9
Sensor thermal resistance
Fuse insert
OC
A
-25÷90
3,15
VI. Assembly
ATTENTION: all assembly works must only be carried out by qualified persons. During assembly, the
device must be disconnected (make sure the power cord is unplugged)!
ATTENTION:improper cable connections may damage the regulator!
VI.a) Cable Connection Diagram for Controller
Pay special attention to cable connections during assembly. Especially, the ground wire should be
connected properly.

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We are committed to protecting the environment. Manufacturing
electronic devices imposes an obligation of providing for
environmentally safe disposal of used electronic components and
devices. Hence, we have been entered into a register kept by the
Inspection For Environmental Protection. The crossed-out bin symbol
on a product means that the product may not be disposed of to
household waste containers. Recycling of wastes helps to protect the
environment. The user is obliged to transfer their used equipment to
a collection point where all electric and electronic components will be
recycled.

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Table of contents
I. Safety 3
II. Description 4
II.a) Basic Terms 5
III. Regulator Functionality 5
III.a) Main Page 6
III.b) Changing the central heating and hot consumption water setpoint temperature. 6
III.c) Firing up/Fan 7
III.d) Manual Mode 7
III.e) Fuel Type 8
III.f) Central Heating Pump Activation 8
III.g) H.C.W. Pump Activation 8
III.h) Operation Mode 8
III.h.1) House Heating 8
III.h.2) H.C.W. Priority 9
III.h.3) Parallel Pumps 9
III.h.4) Summer Mode 9
III.i) Main Screen 10
III.j) Language 10
III.k) Factory Settings 11
III.l) Fitting parameters 11
IV. Protections 11
IV.a) Thermal protection 11
IV.b) Automatic Sensor Check 11
IV.c) Temperature Protection 11
IV.d) Anti-Boil Protection 12
IV.e) Monitoring the flue gas outlet temperature 12
IV.f) Fuse 12
V. Maintenance 12
VI. Assembly 13
VI.a) Cable Connection Diagram for Controller 13

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