Plug in and protect

There are numerous electrical appliances that use the three-pin IEC mains connectors

Problem: . From kettles to computer monitors, this type of connection is as ubiquitous as the sockets on the walls they connect to.
In certain circumstances it is desirable that the socket and the plug remain apart as an unwanted connection to power might result in damage, injury and even death. Devices exist which cap the plug so that it cannot be inserted, but the more ingenious among us would simply find another power cord for the aforementioned kettle or monitor.
Rick Gonzales, while working on the Jefferson Lab Electron Beam Accelerator in the USA, faced this very problem when trying to secure power supplies for ion pumps. "We searched catalogues and asked vendors for a good lockout device we could use on the pumps, but nothing existed for equipment with a removable power cord."
Solution: Duct tape and the words ‘Don’t plug in’ formed the first temporary solution, but since then a rather ingenious device has taken their place.
The Lockout 320 is a plug-shaped device which when inserted, set and locked is impossible to remove. Its main component is a large piece of vulcanised rubber that, squeezed by the compressive action of a metal plate, bulges sufficiently to lock against the internal walls of the socket. Once the screw, which moves the metal plate, has been turned enough to create the lock, a padlock can be inserted through two holes in the shaft and the housing and the socket is secured.
Applications: Despite initial apathy from many manufacturers the device is now available in a commercial form from Southside Safety, the company set up by Rick Gonzales and his wife.
Considering the wide usage of this type of connector, potential applications for a device such as this are many and varied. Two suggested by the inventor are safety, as per the original requirement, and security, whether it is to guard against unauthorised access or to secure uncalibrated or unserviceable hardware. In this respect power supplies and computers have been identified as two potential markets. But whatever the application there is always the need to take account of the 'idiot factor' and normal curiosity, neither of which are necessarily addressed by strongly worded warning signs, however strong the message and however bright the colours. MF
South Side Safety

Tom Shelley

This material is protected by MA Business copyright
See Terms and Conditions.
One-off usage is permitted but bulk copying is not.
For multiple copies contact the sales team.


Supporting Information
Do you have any comments about this article?

Your comments/feedback may be edited prior to publishing. Not all entries will be published.
Please view our Terms and Conditions before leaving a comment.

© MA Business Ltd (a Mark Allen Group Company) 2020