18 Aug The Hidden Specter of Loose Connections
Often, many a telecommunications person will proudly admire the bright cheerful telecommunications spaces, data centers, entrance facilities, and workspace locations. They’ll marvel at how well everything is organized, color-coded, and distributed to meet the needs for the site as well as for the users who function there. But did you know there resides dark and sinister forces behind the walls that can quickly erode that gleaming façade of high-tech gadgetry and well-groomed cable pathways?
They are loose connections! And they can hide in every ac outlet, panelboard, junction box, transformer, and many other locations within the ac electrical system. The International Association of Electrical Inspectors (IAEI) had an article several years ago talking about the impact of loose connection for personnel safety and fire hazards. The facts were sobering but so was the revelation that most people couldn’t tell you the torque specification of many of the electrical terminations, regardless of how simple it is to acquire it.
In this day and age of ‘install it and move on’, preventative maintenance (PM) has seemed to be a thing of the past; especially within the ac electrical system. With the exception of some military/government entities, it is rare to encounter a company who has a regimented program. Simply put, most people will not establish a PM program because it depletes money & manpower. I would be the first to admit that inspecting everything is time-consuming based on my personal site survey experience.
Loose connections are unforgiving and hidden from view. They have such a negative impact on nearly everything related to the safe and efficient operation of your equipment, including:
- Exposing your site to electrical shock and fire hazards.
- Lack of high frequency (HF) noise mitigation.
- Improper application of power conditioning equipment.
- Uninterruptible power supply (UPS) efficiency (or lack thereof).
- Little to no equalization during lightning and electrostatic discharge issues.
- Poor end-use equipment operation.
And while there is no time to visually inspect the connections, some effort should be made to use test equipment to ‘see’ behind the walls. Some of the testers that could be useful are:
- Ground impedance testers (for polarity AND integrity of the wires).
- Micro-ohmmeters (for telecommunications bonding).
Whatever you decide to use to test your ac circuits, (a) follow the IEEE recommended practices and (b) stay away from the three-lamp circuit testers you get at your favorite hardware store! They are notoriously inaccurate. Why, you ask? Maybe that’s another episode for this blog…
To get started on a good PM plan; consult NFPA-70B (Electrical Equipment Maintenance) to get some background on what would need to be done. Then, engage a properly trained and licensed electrician to assist and implement a PM plan that works best for you.
Once you find a deficiency (you and your equipment will be glad you did, trust me), then you can focus the electrician’s efforts exactly where it should be…that is, becoming proactive to correct problems without waiting for something to go wrong. It is important to remember that one loose connection in a hot, neutral, equipment ground, or bonding conductor will impact EVERYTHING in the room so they must be inspected periodically; at least once per year.
Telecommunications bonding should be inspected, as well. There are many types of wiring lugs, connectors, bolts, nuts, and other hardware that is used in a telecommunications bonding infrastructure. Every connection is a potential point of failure…so every one of them must be inspected.
The best advice I can give you for inspecting telecommunications connections is to:
- Be thorough.
- I strongly recommend measuring all connections with a micro-ohmmeter, NOT an earth ground resistance tester. I have used an EGT in the not-too-distant past and encountered a few instances where they are unreliable or lack the resolution needed to check compliance.
- Recognize that each bolt and termination has a torque requirement. To simply state that everything should be ‘as tight as possible’ is ignoring the fact that bonding connections can be too tight, thus distorting the desired ‘metal-to-metal’ contact. Consult the manufacturers of your terminals, lugs, and nuts/bolts to find out exactly what is required.
Finally, if you are measuring your bonding resistance, make sure to retain that data for comparison a year or so down the road. Even if the connection is good today, it could be next year’s problem area.
Good luck and stay grounded!