This indicates the solenoid’s ability to create or
increase energy beyond what is supplied.
When applying an intrinsically safe valve in a hazardous location,
a proper barrier must first be selected. The barrier selection
process must first take into account the parameters the valve was
approved for and compared in the following way :
What this means is that the intrinsically safe valves were tested
against each atmosphere with up to 30 VDC and 175
ma of current across the solenoid and found to still be safe. The other
two parameters are values to indicate how
• Vmax must be greater than or equal to Voc of the barrier.
Voc = Voltage open circuit or maximum allowed out of the barrier
• Imax must be greater than or equal to Isc of the barrier.
Isc = Current short circuit or the maximum current allowed out of the barrier
• Ci plus field wiring must be less than Ca of the barrier.
much energy can be stored or created by the valve :
Ci : Internal capacitance of the solenoid.
This indicates how much energy the solenoid is capable of storing.
Li : Internal inductance of the solenoid.