TECH ST-85 User Manual

ST-85 – USER'S MANUAL

TECH

Declaration of Conformity No. 35/2010

Hereby, we declare under sole responsibility that the ST-85

230V 50Hz thermoregulator manufactured by TECH, ul. St.

Batorego 14, 34-120 Andrychów, 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-85 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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ST- 85 – USER'S MANUAL

ATTENTION!

HIGH VOLTAGE!

Make sure the regulator is disconnected from

the mains before working on the power

supply (cable connections, device

installation, etc.)!

All connection works must only be carried out

by qualified electricians.

Before activating the controller, measure the

motor resetting efficiency, check the boiler

and inspect wire insulation.

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Blow

ST- 85 – USER'S MANUAL

I. Description

The ST–85 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-85 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

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C.H. Pump

H.C.W. Pump

Manual Mode

Encoder knob

Blow

Exit

Standby

ST-85 – USER'S MANUAL

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:

and the controller without PID control:

You can change all parameters with an encoder knob. Turning the knob

allows you to select a function or modify its value, while pressing the knob

allows you to enter the function or confirm changed values. To leave any

function, push the EXIT button.

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ST- 85 – USER'S MANUAL

I.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".

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ST-85 – USER'S MANUAL

In case of voltage loss, the regulator ceases to operate. When power is

restored, the controller returns to operation with previously set parameters

using its built-in memory. Lack of voltage does not cause the stored

parameters to be lost.

II. Regulator Functionality

This chapter describes regulator functionality, how to change settings and

navigate in the menu with the encoder (knob). Depending on the mode the

boiler is currently in, the display will show boiler operational parameters. The

given mode is selected by the user.

II.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 down 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.

Pressing the encoder will move you to the main menu. The display

shows two options of the menu. To select a different option, turn the encoder

knob.

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42 Oc | 55 Oc *

C.H. Setpoint

C.H. Setpoint