NFPA 70E Compliance and 120V Solenoid Valves

What is the general thought of using 120V solenoid valves while maintaining NFPA 70E guidelines? I would think that as long as the connections and cables are hermetically sealed and the wires run to a box designated for >50 voltage, there should be no problem.


There are some opinions about mixing voltages, but sometimes, logistics, supply availability, and existing designs mandate the use of 120V solenoids. Therefore, using <50 for the entire control system except for the valves should be acceptable. There are 6mm "slim" relays that make it easy to design a compact interface box that handles the >50 devices and distribution.

DaDaDadeo said:

What is the general thought of using 120V solenoid valves while maintaining NFPA 70E guidelines? I would think that as long as the connections and cables are hermetically sealed and the wires run to a box designated for >50 voltage, there should be no problem.

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Not sure what your situation is but my job is at a 24/7/365 facility. Down time is a very real problem. Anything that can be done to minimize downtime is welcomed. When 70E became a necessity, designs had to rethought. Any 120V items needed to have disconnects so they could be maintained without shutting down the production line.


We use a large quantity of AB 889 cordsets to accomplish most of the isolation needs

Sometimes the grouping of the 120 volt items was needed to prevent an overwhelming volume of disconnects. Most of our production is linear with a few branch lines. So if one item did fail, quite often the item preceding and the item following the defective item can be shut down at the same time.

DaDaDadeo said:

There are some opinions about mixing voltages, but sometimes, logistics, supply availability, and existing designs mandate the use of 120V solenoids. Therefore, using <50 for the entire control system except for the valves should be acceptable. There are 6mm "slim" relays that make it easy to design a compact interface box that handles the >50 devices and distribution.

Click to expand...

We have chosen to deploy Point I/O instead of slim relays, and label the J boxes as 24 V for those that have only 24 volt items and the ones that have 120 V as "< 1.2 cal" (yes arc flash studies have been done) and they also have an external disconnect to disconnect the 120V for the entire Jbox.