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Description of the control system
General description of the control system
The control system consists of a microprocessor board with built-on display and push-buttons.
Electric heating control
For the electric heated version, the relays for the heating elements are controlled by a time related P.I.D.
controlled function built in the program of the processor, which has the opportunity of a quick reaction with
limited overshoot. The elements are activated by relays.
With the gas version, a PWM controlled ventilator is used, which is controlled by the microprocessor.
This ventilator blows the mix of gas and air into the burner, which means that the power of the burner is
controlled by the microprocessor. The advantage is that also here the burner is controlled with a P.I.D.
controlled function from 20-40 to 100% so that there is a quick reacting system with a low overshoot.
When the need of power is lower than 15%, the burner will be temporarily switched off.
The temperature of the roll is measured by Pt1000 elements that are mounted on a contact plate on the
roll. The Pt1000 are directly connected to the microprocessor board.
To prevent overheating when there is a malfunction of the Pt1000 or the microprocessor board,
a maximum temperature switch is placed, which switches off the power of the relay of the elements or the
power of the gas control unit.
temp2: left sensor
temp1: right sensor