When an IT Network Cable Kept Tripping the Building's Electricity

Not every IT problem is an IT problem. Some sit at the boundary between networking, infrastructure and electrical engineering — and finding the right answer depends on knowing where to look.

The Problem

A customer contacted us after experiencing a strange and disruptive issue. Their building's electrical supply would randomly trip — but only under certain conditions. After some investigation, staff noticed the problem almost always occurred when a particular network switch was connected to the LAN.

On the surface it looked like either faulty networking equipment or an electrical fault. Replacing the hardware hadn't solved the problem.

Our Investigation

Rather than assuming the switch itself was defective, we stepped back and looked at the wider picture.

By testing different combinations of equipment and tracing how the network was connected throughout the building, a pattern emerged.

The building had two separate electrical supplies feeding different areas. Although the electrical systems were separate, the copper Ethernet cabling between the network switches created an electrical path between the two sections of the building.

Connecting the network cable effectively bonded the two earth systems together. The network wasn't carrying the problem — the copper cable itself was providing an unwanted electrical connection.

Root Cause: Copper Cable Creating an Unwanted Electrical Path

Copper Ethernet cabling doesn't just carry data — it also provides a conductive path between devices. Where two parts of a building are supplied from different electrical systems, differences in earth potential can cause current to flow through that copper connection.

In this case, connecting the switch completed the circuit and caused the building's protection systems to operate, tripping the electricity.

This wasn't an IT equipment fault. It was an interaction between the building's electrical infrastructure and the network design.

The Solution

Once the cause had been identified, we recommended separating the network using fibre optic cabling between the affected sections of the building.

Unlike copper Ethernet, fibre carries light rather than electricity, providing electrical isolation while maintaining full network connectivity.

Results:

• No further electrical trips.
• A more resilient network design.
• Improved protection against electrical faults and surges.
• A solution aligned with networking best practice for larger buildings.

Why This Matters

Many IT problems aren't purely IT problems. They sit somewhere between networking, infrastructure and electrical engineering.

Finding the answer required experience, logical troubleshooting and a willingness to challenge the obvious assumptions rather than simply replacing equipment.

At Altitude IT Support, we believe solving the real problem is more important than replacing parts until something works. Sometimes the most valuable tool isn't a new switch — it's knowing where to look.

We work with businesses across Manchester, Greater Manchester and the wider North West, providing business IT support that goes beyond basic helpdesk responses.