Answer / jp

Normally, all instruments to be grounded to clean earth (should be less than 2 Ohms). Whereas Electrical earth resistance might be more than this. So Instrument earth pit to be seperate from electrical earthpit.

Answer / sam

The internal screen is always floating at the instrument.
This means we just put some heat shrink on it to seal it and
then tie it off inside the instrument and just let it lie
there. The overall screen (braiding surrounding the cable
just below the pvc outside)will be in contact with the gland
once you have installed the gland. On the gland thread you
install a copper gland ring and a red IP washer, and the
gland then are attached to the instrument. From the gland
ring you use a six mm bolt and nut with copper washers to
attached a small diameter earth wire (about 4 to 6mm is
fine). This earth wire is then attached to the outside of
the instrument at the earth connection point on it's
housing. Every instrument will have this earth connector on
the outside of it's housing. From there you attached another
earth wire to the earth boss nearby. This boss is normally
just a piece of round bar about 40mm in diameter and about
30mm long and tapped in the middle that is welded to the
structure close by, specially for this earthing of the
instruments. Again it is better to use copper washers. If no
boss is available you can use some other point on the
structure as well like a stainless steel cable tray for
instance but the earth boss should really be part of the design.
On the other side of the instrument cable at the RTU the
internal screen in attached the instrumentation clean earth.
The dirty earth is used only for electrical equipment.
Good luck

is motorized valve closed when power shutoff?

0 Answers   Unilever,

---

why using negative supply for bentley nevada vibration system ?

0 Answers  

---

what is linerity and non-linearity?

2 Answers  

---

Can any body help me,The GE Mark V control system is windows based or Dos based?

3 Answers  

---

i have done DAE in Instrumentation and Process Control. i have applied for an apprentice training in chemical company after three day my interview will be conduct but i need more information about industrial process control and controller. my e mail is imran_dilsetu@yahoo.com please tell me interview question relative to instrumentation ?

0 Answers  

---

how to calculate density?

2 Answers  

---

why I need valve guard and whats different between guard and positioner ??

0 Answers  

---

hello i'am samad.Any one Can help me! How to calibrate Vaccum Transmitter DP Type range 0 - 50 mbar abs by hand pump calibrator.

4 Answers   Bharathi Cement,

---

can we use a control valve without positioner

19 Answers  

---

Please anyone answer my question, what is the difference between single acting and double acting control valve, in what condition we better choose single acting rather than double acting

2 Answers  

---

What is rated capacity in Control valve

3 Answers  

---

What is Hysteresis mean in Instrument?

11 Answers  

---