what are the standards used for earthing instruments in the
field?
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 This Answer Correct ? | 3 Yes | 0 No |
Explain Split Range Control In Control Valve Briefly.
For an Instrumentation Engineer, is there any effect on Instruments of safety zones like zone0, zone1, zone2. As an instrumentation Engineer, what we have to consider or remember while working in these areas.( zones 0,1,2).
how u meassure room temp?is it possible 2 meassure room temp by rtd or thermocouple?between rtd n thrmocouple which is more regard?3 meassure diff. between rtd n thermocouple?
What happen if I install my pressure transmitter below the elevation of pipe in natural gas service?
Specify eight technical requirements that you would consider important, when deciding upon a particular control valve?
Foe selecting control valve if i have the min,normal & max data of flow rate,inlet pressure& outlet pressure,inlet tem.&density than how can i assure that these data are correct,pl. let me know if therew there is any method to check it.& also how we assure that the Cv we get from this data is suitable for valve for controlling require flow.
why is honed type flow orifice plate? what purpose it used? how to select this?
Draw block diagram BOILER COMBUSTION loop & Explain
1 Answers Bajaj Hindusthan, Exxaro,
how to convert % to ma
1 Answers Flour Tech Engineers (P) Ltd, Techint,
Can be operate control valve without positioning if yes ? how and why?
The Design Calculation of Level Transmitter For Different Structure open & Closed Vessel, Eg. Diff. Level Tx., Capacitance For Continous Operation
what is instrument philosophy