Hi friends, from Aug 4th onwards iam getting spikes for
analog inputs in our DCS for a period of 800ms. I throughly
checked every thing, finally i found that the DI, DO's from
MCC panels shields are terminated in the Signal Earth where
Analog Input signals shields are terminated. Is there any
problem with this type of termination?. i checked the
induction voltage from MCC and getting around 25VAC, please
suggest me in this concern. Our plant is 8months old only.
DCS is Siemens Make Simatic PCS7, and the transmitters are
Yokogawa make.
- 1 Answers
- 3732 Views
- I also Faced
- E-Mail Answers
Answer Posted / sankarithi
Hi Friends only problem is due to earth pit. I throughly
checked every thing, finally i found that the Earth pit
totally became dry. I serviced the pit,Now there is no
spikes.
| Is This Answer Correct ? | 4 Yes | 1 No |
Post New Answer View All Answers
Explain the working of an enraf level gauge.
Somebody tell me in what way i need to prepare for csio pgrpe(adv instrum eng)interview?what all the quest can i expect?
i have used level transmitter in starch cooking preparation tank. tank total height 2mtr.sometime LT display shows some error value when tank is fully empty and diaphragm side i already checked okay no problem in diaphragm area. field cable checked 24volt and mA shows correct value while tank empty mA is 4mA. 4mA i needed that 0% but display showing 10% or 15% percentage values are varying continously please give any good solution for me.....
1.what is the effect of vapour presuure in orifice plate flow measurement 2.which is more effective 2 pressure sensors or one single differential pressure sensor in orifice plate measurement 3.how to design a v/i converter and i/v converter 4.how many type of thermocouple are there 5.how many leads are there in thermocouple measurement 6.how pressure sensors are connected in level measurement in differential pressure method 7.what is the output of capacitive pressure sensor (ac or dc),how its o/p is signal charactarized 8.what is the physical meaning of discharge coeeficient,why it is calculated,orifice plate what is its value,why it is less than 1,Q at upstream is equal to or not equal to Q at downstream of orifice plate why?what is vena contracta in orifice plate 9.why rotameter is called variable area flowmeter,it can measure flow even if area is not varying,why it is made tapered 10.design a 10 bit counter ,which counter you will prefer 11.how to remove self heating error in RTD 12.which is more sensitive pt100 or pt50 13.why thermocouple are connected in parallel 14.what is lead contact error in RTD,how to avoid 15.what is P,PI,PID,PD controller,why there is no ID controller 16.what is override,split range,sequential,ratio,feedforward,cascade controller 17.why we moved from SR to JK and then JK to master slave JK flipflop,give correct reason 18.how to measure level of a closed container which contains vapour and liquid,remember no vapour gas should be leaked,so ultrasonic and capacitive is not an option,design another method 19.how to design horse race counter including sensors and signal conditioning element 20.what is bevelling
when placing a vent or drain hole on an orifice plate should you measure from the center of the bore up or down for the vent placement?
why direct mounted pressure transmitters is always installed with DBB ( double bleed block) valve in process line or top of the tanks ?
Where Can i take a SPI INtools training in Mumbai? In Rolta India Ltd to whom I should approach regarding of SPI INtools Training?
what is the procedure to callibrate temp controller ,pressure controller,etc. suppose a temp controller showing error 1.5 degree centigrate how can i minimize it.
what is a vortex flow meter,mass flow meter and electromagnetic flow meter.particular use of this.means in which condition particular meter is used.
how to calibrate Necleuonic level transmitter.?
What are the uses of orifice plates?
defination of radial vibration?
What is the diffrence between ff tx and non ff tx
Instrumentation symbols interpration, P& ID, Logic diagram analysis, Electrical drawing analysis.
what is the difference between attemperator and desuperheater ?
