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Dear all
We have Siemens 8.6 Megawatt back pressure steam turbine, which have installed voith converter on it to control the hydraulic system and voith is controlled by 505 digital controller.
The problem is that at idle state servo/actuator valve fails to open 100%. It remains still at 75% even the mA are measured 20mA.
505 digital controller is configured for 4-20mA.
when we start the test auxilliary oil pump is switched on lube oil pressure remains at 1.9 bar(recommended is 1.5 bar) and control oil pressure remains at 7 bar (recommended is 8bar) and secondary oil pressure remains at 1 bar (recommended is 0.8 bar).
when we input 25% to 75% opening through 505 controller the measured mA signal remains okey that is 4-16mA and servo/actuator valve opens as desired. But when we input of opening 75% to 100% through 505 controller the mA reaches to 20mA but servo/actuator valve fails to open further and rests at 75%.
During the test only secondary oil pressure gradually increases from 1 bar to 3.2 bar while other oil pressure remains same.
Does anyone has the solution for that ?
We have Siemens 8.6 Megawatt back pressure steam turbine, which have installed voith converter on it to control the hydraulic system and voith is controlled by 505 digital controller.
The problem is that at idle state servo/actuator valve fails to open 100%. It remains still at 75% even the mA are measured 20mA.
505 digital controller is configured for 4-20mA.
when we start the test auxilliary oil pump is switched on lube oil pressure remains at 1.9 bar(recommended is 1.5 bar) and control oil pressure remains at 7 bar (recommended is 8bar) and secondary oil pressure remains at 1 bar (recommended is 0.8 bar).
when we input 25% to 75% opening through 505 controller the measured mA signal remains okey that is 4-16mA and servo/actuator valve opens as desired. But when we input of opening 75% to 100% through 505 controller the mA reaches to 20mA but servo/actuator valve fails to open further and rests at 75%.
During the test only secondary oil pressure gradually increases from 1 bar to 3.2 bar while other oil pressure remains same.
Does anyone has the solution for that ?
