Today is...
Monday, March 18, 2019
The Automation Safety Community Forum.
Intrinsic Safety Barrier Selection
Calculation methodolgy for IS barrier entity parameters.

I need to evaluate the intrinsic barrier entity ratings for a loop having a DVC 6200 positioner in series with a field communicator connected in parallel. Following are the entity parameters of the devices:

DVC 6200:
Vmax = 30VDC
Imax = 226 mA
Ci = 5nF
Li = 0.55mH

Field Communicator:
Vmax = 30VDC
Imax = 200 mA
Ci = 0nF
Li = 0mH
Voc = 1.9VDC
Isc = 32uA
Ca = 100uF
La = 5600mH

What will be the values of Voc, Isc, Ca and La of the barrier?