Dry Contact RIB Relays Stop Voltage Drop

Tech Tuesday Dry Contact RIB Relays Stop Voltage Drop

Wireless technology is a fantastic thing. It allows people to control devices that are hundreds, if not thousands, of feet away. But what if wireless isn’t reliable enough? What if wireless is too expensive? What if you want a hardwired solution? No one wants to run thousands of feet of wire. That’s expensive both in labor and parts, not to mention the voltage drop that occurs across that span of distance. Enter Functional Devices’ Dry Contact RIB Relays.

Fortunately, as I’ve previously mentioned, RIB® relays are perfect for many niche applications. They require constant voltage, but the relay activation is controlled by the closing of a Class 2 dry contact. That’s right – no conduit needed. We have 10A, 20A and 30A models with this dry contact input feature, and they come in SPDT, DPDT and 3PDT configurations. There are also a couple models with time delay options.


A customer wanted a switch in an airport control tower to open a fire station’s garage doors. The tower itself was around 300 feet tall, and the distance to the fire station was more than that. The customer was looking at a total distance of a minimum of 1,000 feet. They didn’t want wireless communication for reliability reasons and already had existing wiring between the tower and the airport fire station.

Solution: Dry Contact RIB Relays

RIB01BDC Dry Contact RIB RelaysOur RIB01BDC was the perfect solution! Because they had existing wiring, and the dry contact RIBs can be put in parallel, only one run of wire was needed for all the relays. Opening a few garage doors from a thousand feet away for about $100? I’d take that!

I have personally hooked up 10,000 feet of wire (5,000 feet down and 5,000 feet back) for testing purposes, and there was no difference in operation from closing the contact at the RIB®. Imagine activating a 24V load 5,000 feet away without any voltage drop. Also, imagine activating a 480V 3-phase 7.5HP motor from that distance just by closing a Class 2 switch. With a RIB® relay, it’s possible!

David Mackey
David Mackey

David Mackey is an Engineer for Functional Devices. He is a husband of one, a father of three, and a servant of Christ Jesus. David graduated from Purdue University with an Electrical Engineering Technology degree. He enjoys working with his hands on things like woodworking, cars and, of course, electronics. He is 5' 13" and wears glasses, unless he wears contacts. He is also a self-made hundredaire.

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