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浙大中控dcs卡件XP313:DCS係統無法操作調節閥怎麽辦?

2021-01-11 16:58:49 來源:http://www.qistar-garment.net/ 53

故障現象
Fault phenomenon
PIC708從DCS操作站上無法控製調節閥。操作界麵顯示該點為“初始化”狀態。
Pic708 can not control the control valve from DCS operation station. The operation interface shows that the point is in "initialization" state.
故障分析
fault analysis 
出現此現象,一般為DCS輸出回路開路所致。如定位器損壞,接線鬆動,斷電、安全柵損壞等均能引起此故障。由於現場環境惡劣,震動較大,首先考慮是否為定位器接線鬆動所致。
This phenomenon is generally caused by open circuit of DCS output circuit. If the positioner is damaged, the wiring is loose, the power is cut off, and the safety barrier is damaged, the fault can be caused. Because of the bad environment and large vibration, the first consideration is whether it is caused by the loose wiring of the positioner.
處理過程
Treatment process
1.辦理好在線檢修作業票後,到現場檢查,發現定位器接線無鬆動。測量定位器工作電壓為4.95V,該定位器為FISHER公司DVC6010型智能定位器,工作電壓應該在10V左右。斷開定位器的接線,測開路電壓為17.5V,正常。再測其短路電流(因該定位器為有源隔離柵供電,所以現場短路測量不會影響其本安特性),隻有0.78mA,正常值應大於20mA。看來供電不正常。為確定是單純供電問題,還是因為定位器損壞造成的供電異常,用一台信號發生器給定位器加入電流信號,調節閥工作正常。由此可以斷定故障出在定位器之前。
1. After handling the online maintenance work order, the on-site inspection found that the locator wiring was not loose. The working voltage of the positioner is 4.95v. The positioner is Fisher dvc6010 intelligent positioner, and the working voltage should be about 10V. Disconnect the wiring of the positioner and measure the open circuit voltage to be 17.5V, which is normal. The short-circuit current is only 0.78ma, and the normal value should be greater than 20mA. It seems that the power supply is abnormal. In order to determine whether it is the simple power supply problem or the abnormal power supply caused by the damage of the positioner, a signal generator is used to add the current signal to the positioner, and the regulating valve works normally. It can be concluded that the fault is before the positioner.
                       浙大中控dcs卡件XP313
2.檢查定位器至中間接線箱至機房的電纜,線路電阻均正常。由此,故障縮小到DCS輸出卡件到機房端子排之間。
2. Check the cable from the positioner to the middle junction box to the machine room, and the line resistance is normal. Thus, the fault is reduced to between the DCS output card and the computer room terminal block.
短接DCS輸出卡端子,DCS界麵的故障消失,排除卡件故障。在短接安全柵的輸出側,故障不消失,將此處端子鬆開後重新壓緊,短接故障可以消失,但不短接,故障仍然存在,說明故障不止一處。短接安全柵的輸出側,故障沒有消失。但是這一側直接連接現場的定位器,從這一側到定位器之間的線路已經測試過,沒有問題。會不會是安全柵性能變劣,帶載能力下降所致呢?
If the terminal of DCS output card is short circuited, the fault of DCS interface disappears and the card fault is eliminated. In the output side of the short circuit barrier, the fault does not disappear. If the terminal is loosened and pressed again, the short circuit fault can disappear, but if it is not short circuited, the fault still exists, indicating that there is more than one fault. Short circuit the output side of the safety barrier, and the fault does not disappear. But this side is directly connected to the field positioner, and the circuit from this side to the positioner has been tested, and there is no problem. Can it be caused by the deterioration of barrier performance and load carrying capacity?
3.將安全柵輸出側接線斷開,在此處接入一個250歐姆的負載電阻,此時故障消失,電壓為1V,電流為4mA,將250歐姆的負載電阻拆下,將接線複原,儀表故障消失,定位器電壓為9.6V。由此可以看出,安全柵的輸出側也存在接觸不良的情況,當斷開又重新壓緊後,故障排除了。
3. Disconnect the wiring at the output side of the safety barrier and connect a 250 ohm load resistor here. At this time, the fault disappears. The voltage is 1V and the current is 4mA. Remove the 250 ohm load resistor and restore the wiring. The instrument fault disappears and the locator voltage is 9.6V. It can be seen that the output side of the safety barrier also has poor contact. When it is disconnected and pressed again, the fault is eliminated.
結語,本例中,故障是因為安全柵的輸入端同時存在接觸不良的情況所致。由於接線均壓有針型接線端子,上緊後,經過一段時間,由於金屬材料的形變及氧化,使得接頭出現鬆動及接觸電阻變大的現象,從而引起儀表的故障。查明原因後,利用裝置停車消缺的時機,將機房內所有接線端子緊固一遍,查出多處線頭鬆動的問題,及時消除了隱患。
Conclusion: in this case, the fault is caused by poor contact at the input end of the safety barrier. Because there are needle terminals in the wiring, after a period of time, due to the deformation and oxidation of metal materials, the joints become loose and the contact resistance becomes larger, resulting in the failure of the instrument. After finding out the causes, the device was used to stop and eliminate the defects, and all the wiring terminals in the machine room were fastened once. The problems of loose wire ends in many places were found out, and the hidden dangers were eliminated in time.
建議,裝置在檢修期間,應當檢查控製係統接線櫃、中間接線箱和現場儀表接線,並且進行清灰和緊固端子工作,尤其是振動比較大的區域。
It is suggested that the wiring of control system wiring cabinet, intermediate wiring box and field instrument should be checked during the maintenance of the device, and the dust cleaning and terminal fastening should be carried out, especially in the area with large vibration.
以上是浙大中控dcs卡件XP313對DCS無法操作調節閥的原因介紹,希望對大家有所幫助,如想了解更多精彩資訊請點擊丝瓜视频免费下载的網站:http://www.qistar-garment.net
The above is the reason why the DCS card xp313 of Zhejiang University central control can not operate the control valve. I hope it can help you. For more wonderful information, please click our website: http://www.qistar-garment.net
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