Best choices for a Zone 1 application?
Question: I am looking for an intrinsic safety barrier suggestion for a simple 2-wire float switch (open/closed) to use in a Zone 1 hazardous area. I'm trying to turn on a 24-volt signal light when the float is activated.
Answer: We have many different options for a simple 2-wire float switch, but first, a little background information. Since a float switch is considered a simple apparatus, the product itself does not need to be rated as intrinsically safe, but it still must be used with an intrinsically safe barrier to be located within the hazardous area.
The most common barrier we would recommend would be our single-channel, galvanically isolated, KCD2-SR-Ex1.LB. It comes in a slim 12.5 mm wide housing and has two Form A relay contact outputs. The output state of the relays can be changed with DIP switches on the barrier to energize with either high or low input current. The barrier itself must be powered with a 24 VDC supply.
We also have a variety of other relay output barriers that could be used in this application. Some of the options include AC powered barriers, single-channel, dual-channel and four-channel variations.