RE: High-Current Terminal Blocks: Powering the Future of Industry

Umuju — Tue, 17 Sep 2024 11:55:00 GMT

I’ve had pretty good experiences with your products in low voltage applications, but some of the issues I’ve run into would be compounded by higher current loads. I am curious of the ways this technology can simplify installation and troubleshooting, but I would like to know if/how some of these concerns have been addressed.

The first concern would be if sufficient force can be applied to the wire when terminating larger conductors such as a 350 kcmil. Typically, the amount of force necessary to ensure a solid connection will deform the wire and flatten it to the sidewall of the lug. In instances where sufficient force was not applied, the heat generated at the point of termination was enough to melt the insulation on the conductors back to the raceway and caused a short.

My second concern would be the method for installing or removing the conductors. If sufficient force is being applied to ensure a good connection, greater force would need to be applied to release the tension allowing the conductor to move. My past experience with DIN rail mounted connections has given me doubts as to the ease or reliability of the options available. In using lever type WAGO connectors, I have had the lever used snap on the first attempt to open the block for termination. On screw type mounts, the plastic housing will often try to twist or even break. The slot type releases have similar issues as the housings are affected by the force necessary to release the pressure on the termination.

My final question would be of longevity. Over time, connections can become loose. Many companies have employed IR scanning of their equipment to map potential hot-spots and schedule maintenance. While this would require a shutdown, the only cost would be the manpower to tighten the lugs to spec and inspect the conductors for damage. In most cases, this can be accomplished at the time of the IR scan. If the pressure being applied is from a spring, I would be concerned how quickly the spring loses its ability to apply the required pressure and if this is adjustable, or would the full unit need to be replaced to be able to apply the appropriate amount of force. As most of the structure or the units are plastic, would they hold up to not only the force being applied to hold the conductors stable, but also to the force needed to install and remove the conductors? As plastics are exposed to different temperatures, they can become soft and/or brittle. When fluctuating between these states over time, the overall integrity degrades.

I do like the convenience that WAGO offers with their connections and have been impressed with the improvements I’ve seen, but the issues I have encountered with spring pressure wire connections have limited my willingness to use them in my trade. My largest concern is with the reliability of the connection over time, and I haven’t seen a method of connection that I trust with the higher current demands that require larger wire.

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RE: High-Current Terminal Blocks: Powering the Future of Industry