Telecom CO Spotlight: Spare Cabinet ESD (electrostatic discharge)
In everyday life, ESD or electrostatic discharge is a fairly harmless phenomenon. On a cool, dry day you may brush against something, creating a small electric charge that you then discharge with a little arc of electricity and a small, slightly painful “zap.” If you have touched a person, they may be annoyed, but if you have managed to be near delicate circuitry or other electronic equipment while charged, ESD could damage the part.
As such, in the telecommunications world, electrostatic discharge is a much more harmful issue. With both in-use cabinets controlling telecommunications switching and spare plugs stored in the building, a little zap—or even the possibility of static—can mean a lot of wasted equipment and money.
According to many organizations’ rules and operational guidelines, if a plug or cabinet holding that plug is “improperly stored," that asset must be considered defective, and in turn unusable or unfit to be kept as a working spare. Guidelines differ, but improper storage with regard to ESD can include:
- Storage without ESD mats. ESD mats are foam, vinyl, rubber, or made of another non-conductive material and are placed under and around critical equipment to diffuse ESD deriving from a person working on or around the item.
- Packaging of equipment in non-ESD bubble wrap or boxes. We will go into this in more detail in a future post, but equipment waiting to be used or waiting to be shipped to another CO as a working spare must be packaged in anti-static bubble wrap and approved boxes to be considered ESD-free and acceptable.
- Components touching each other while stored. Equipment that is touching other equipment has the potential to transmit a static discharge from one item to another if one is charged. This could create a chain-reaction of damage wherein one plug is shocked and that shock cascades to all others, damaging all. If items are far enough apart, the charge will dissipate instead of arcing from one piece of equipment to the next.
According to Alden Quality Assurance expert Suzanne Knott, “We see stacks and stacks of plugs in storage cabinets that they consider “good," and they are probably not due to improper storage.” Beyond equipment-focused precautions, there is also a human element to protecting assets from electrostatic discharge. “If you really follow the guidelines, you will notice that before you even touch one of those plugs, you are supposed to have an electrostatic discharge grounding strap on your wrist and sometimes on your feet before you even get close to the equipment.”
This is a serious “better safe than sorry” situation. Some large blades—plugs with dozens of circuit boards—can cost between $20,000 and $40,000 each, and while one benefit of a thorough inventory is to retire assets from a company’s books through weeding out items that are not useful, losing large amounts of assets due to improper storage is not acceptable.
The solution? Maintain a safe distance between stored plugs to mitigate the risk of static arcs from one cabinet to the next. Wrap and pack plugs in approved anti-static materials, and keep in mind the human aspect of the equation. ESD gloves, footwear and wrist straps are readily available and easy to use by technicians.
An ohm of prevention is worth a powerful pound of cure.