So the date-code shown above indicates that the panel was manufactured on December 15th of 1967 or 1988, by operator #924, on the first shift. Since the letter indicating year of manufacture can be one of several that are 21-years apart, you should evaluate the condition of the panel to determine which one that is most likely correct. Year of construction of the home, along with the year of any remodeling or electrical upgrades can further clarify it.
Here’s another example, below, that was manufactured on September 29th of 1952, 1973, or 1994, by operator #462, on the first shift. In this case, since we knew that the home was built in 1995, it was easy to establish that 1994 was the year of manufacture.
Panels from the late 1990s until the present most commonly use a five or six digit code, where the first two digits are the year, second two digits are the week. So “991731” would have been manufactured in 1999, on the 17th week of the year.
To get date-code sequences for panels earlier than 1956, download the Schneider Electric pdf from this link: SquareDDate.pdf.
While we hope you find this series of articles about home inspection helpful, they should not be considered an alternative to an actual home inspection by a local inspector. Also, construction standards vary in different parts of the country and it is possible that important issues related to your area may not be covered here.
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