Do i need to use a Flameproof RTD (in Hazardous area) when i am using a P & F make barrier in the control panel.
Or i will do with Weatherproof .

 

If you are using an intrinsically safe explosion protection method for the complete circuit, you do not need to use a certifies RTD - these are
incapable of storing or generating energy and are classified as "simple apparatus" in the commonly-used codes of practice - IE IEC and NEC.

You do need to make sure the complete circuit between the barrier in the control panel and the hazardous area complies with the requirements for
intrinsic safety.

Bruce.

 

What are the points i need to take care to ensure that the complete circuit between the barrier in the control panel and the hazardous area complies with the requirements for
intrinsic safety.

regds -

Sumit

 

Oh boy - A full answer to this is worth about 4 hours on one of my training courses ...

1. Either on the barrier itself, or printed in the documents you received with it, will be values for Cmax and Lmax. These indicate the maximum values of capacitance and inductance that can be connected to the barrier without exceeding permissible energy levels for the atmosphere you will be working in. The cable between the barrier and RTD must have total
capacitance and inductance which are below these levels.

2. The IS cable pair must be kept segregated from any non-IS circuits - at least 50 mm separation.

3. No non-IS components can be connected in to the IS circuit - eg local indicator.

But if you are at all unsure about this, obtain a copy of the applicable standards and make sure you fully understand what you are doing, and what
the requirements are.

Bruce.