Surge Protection on flowmeter mounted outside

Hello,

I am doing a bit of electrical design and had a flowmeter that is going to be mounted outside. The area is prone to lightning so I am going to have surge protection on the flow 4-20mA analogue output before the PLC card, also there is a totaliser digital output that I am going to have a surge protector before the PLC input card.

My question is:-

the flowmeter is 24VDC powered, do I need a surge protection on the flowmeter 24VDC power? I assume I dont as this is connected to a powersupply that is not sensitive like PLC cards?


Thanks for advise

Matt

I use signal isolators for my external mounted flowmeters for the very same reason. Red Lion, and Pheonix Contact.

Thanks for the reply, but I take it you use a signal isolator on the 4-20ma flow analogue output,

what about the power of the flowmeter or is it assumed that no protection is needed as the power supply (not the flowmeter one, the one mounted in the building would be harder to damage?

It's my personal preference to protect 'em all. Others say I tend to overdo the lightning protection, but I do it because it's so expensive to repair/replace instrumentation. A little protection goes a long way.

I put protection on outside mounted power lines, as well as the signal line.

Dan