My last article provided a history and background on Article 400, dealing with flexible cords and cables. This month, I delve further into whether flexible cords and cables could or should be installed in concealed locations.
Concealment of flexible cords and cables that are installed as an integral part of appliances—or when used for connecting other electrical equipment—is an ongoing issue for the electrical industry. The history of the National Electrical Code (NEC) provides some insight.
The last two columns covered fiber optic power meters, test sources and the reference cables you need to test the loss of installed fiber optic cable plants. This month, I discuss using these instruments properly and how to determine if a tested cable plant passes or fails the test.