Transmitter with Transient Protector

Based on a half dozen experiences with near-lightning strikes to instrumentation, I find that transmitters located outdoors in areas frequented by lightning are those that need surge protection. In only two cases did the transmitters have surge protection. In the one case, the surge protection blew up but saved the transmitter electronics, in the other case the transmitter was damaged beyond repair. In the other four cases, transmitters had no surge protection and the electronics were destroyed, presumably by a near lightning strike.

I work in a area where spring summer and fall have common thunder lightning storms, and lightning in the winter tends to be rare, but not unknown.

I'm sure that somewhere in the world, there are locations that rarely, if ever, get lightning.

I routinely use two RS-485 isolators on Modbus RTU RS-485 network comm lines

a. to protect the master from an electrical fault or lightning affecting the 485 network

b. to isolate and protect half the devices on a multidrop network, in case of an electrical fault or lightning affecting the 485 network.