Answer / banerjeenandan

Normally there should be different grounds in control room.
DCS or PLC vendor generally gives the drawing.

Mostly it is taken as convension that there should be 3
different grounding busbars in control room.

1. One is for the power earth. This will give the earthing
to the power distribution panel of the DCS or PLC.

2. Second is the Signal earth. All the shield cables will be
connected to this earthing busbar to minimize the
interference in the analog signal cables.

3. Thrd is Panel earth. This will be connected to the panel
body.

All these 3 busbars should be connected to 3 different
earthpits by 3 different Copper cables. Redundancy of
earthpits or copper cables may be there if possible.

how can we caliberate interface level troll

2 Answers   Grasim, IOCL, KOC, Sankyu,

---

If an Instrument has 550 ohm internal resistance and the cable used for that instrument is 0.5 ohm per meter resistance. If the voltage is 12volt.How much length cable can be used? Please tell me its Calculation formula.

5 Answers   MOL,

---

1. How many output signals do wew have in process control? 2. Could you write down the names of the pre-commissioning and commissioning stage test instruments and explain them (more than 5 items)? 3. What is the first step to commission a transmitter on service? 4. What is RTD? 5. Find the output value in MA of a temperature transmitter (RTD Type) at 120degree celius? 6. What is the O/P signal of a pneumatic transmitter? 7. What is the O/P signal of an elctronic transmitter? 8. What is the close loop and open loon?

4 Answers  

---

What is difference between radial vibration and axial vibration explain in detail .

0 Answers   Emerson,

---

I have 0.75mm sq multicore cable (IS type) , can use instead of same type but 1.5 sq mm cable ? Note : The distance is around about 150 meter.

0 Answers  

---

What is the purpose of LO overhead tank in turbines.

1 Answers   ADMA OPCO,

---

hi this is noor i wnt know the procedure and precations errection for PRESSURE AND DP transmitters? how to take impusle line for level and flow?(water and steam) impulse line sizes? and type of material ? plz give me answer / reffer any website ? to me "mail2noor.hyd@gmail.com"

1 Answers  

---

in which mode of the zener diode act when load voltage is approximately constant

1 Answers  

---

dear friends, i have seen flow as the selection critriea in presure guage (bourdon tube) and i would like to know what is the relation between flow and performance of pressure guage other parameters i found in the data sheet are pressure max. 1ksc temperature max. - 50 deg c line size - 80NB operating range - 1ksc pr. guage range - 0-2 ksc thank u,

0 Answers  

---

Specific gravity.

0 Answers   CCIE,

---

what is the use of shield cable?

2 Answers  

---

How can we test a bently nevda 3500/42M accelerometer monitor card by simulating it with test equipment?. what king od of signal (milli volts or volts or or resistance ) we should feed in the terminals of the card?

0 Answers  

---