SAS ST-550 zPID, Руководство пользователя

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User’s manual
8
IV. How to use the controller
IV.1.
Principle of operation
The regulator controls the fan and the fuel feeder operation so that the pre-set temperature of the CH
boiler and the water tank is reached. Additionally, it controls CH and DHW pump operation activating
them once a pre-defined temperature of the CH boiler has been reached.
IV.2. Stages of operation
Fire-up – this phase is initiated when the flue gas temperature reaches a pre-set value and does not
drop below this value for 30seconds (default fire-up time ).
Operation – when the fire-up phase has been completed, the controller enters operation mode and the
display shows the message ‘PID: OPERATION’. It is the primary mode of controller functioning when the
blow force and fuel feeding are regulated with PID algorithm, oscillating around the pre-set temperature
defined by the user. When the temperature increases unexpectedly by more than 5
o C above the pre-set
value, the supervision mode is activated.
Supervision mode – this mode is activated automatically when the temperature exceeds the pre-set
value by more than 5 o C in operation mode. In such a case, the controller disables PID control and uses
manual settings (according to parameters defined in the fitter's menu).The display shows the following
message: ‘
PID: SUPERVISION’
IV.3. zPID control
ST-550zPID is a controller with continuous output signal, using z PID algorithm . This type of controller
calculates the blow force on the basis of CH boiler temperature and the flue gas temperature measured
at the CH boiler outlet. The fan operates continuously and the blow force depends on the CH boiler
temperature, the flue gas temperature as well as the difference between these parameters and their pre-
set values. One of the greatest advantages of zPID regulators is their ability to maintain a stable pre-set
temperature without unnecessary overregulation and oscillations.
Apart from zPID control, the controller operation is adjusted on the basis of the the readings from
the air flow sensor mounted on the fan.
Using this type of regulator with a flue gas sensor helps to reduce fuel costs by up to several percent.
Moreover, it ensures stable temperature of output water thus prolonging the life of the heat exchanger
(of the CH boiler). Flue gas temperature control results in low emission of dust and environmentally
harmful gases. Flue gas heat is not disposed of through the chimney, but it is utilised for heating
purposes
.
TEST RESULTS - TECH controller with PID control: