Majority of dynamoelectric control valve is input of 220VAC power source, 4-20mA, output. If computer terminal does not have a powerful person show, whether does the input line that needs to check 4-20mA break a string, the contact contact that inputs module is good; If dynamoelectric control valve is not moved, need to check output circuitry, output the dot of module, coil of the starting electric capacity that examines electric machinery, electric machinery is in good condition.
2. 2 inverting are controlled
(1) craft requirement
Shut above all cut off a powerful person quickly (abbreviation cuts a powerful person quickly) , cut off gas execute commutation. Its control a process to be as follows:
(2) control a principle
Gas the motive force that cuts a powerful person quickly is nitrogen or compress air, control by air cylinder gas cut a powerful person quickly. Control process is as follows:
The coil of electromagnetism a powerful person that the coil that feels a CPU315 to give out the instruction → number that involves a powerful person to measure output to feel a SM322 to output pulse → auxiliary relay when the processing central closes → often opens a dot to close → involves a powerful person gets electric → to open nitrogen to be in charge of, drive a powerful person such also.