Tandem breakers

This is a general question for any electrical experts out there regarding tandem breakers. I know the "rule" to follow to determine if tandem breakers are allowed, or in what locations, in an electrical panel. For example if the model number is something like G3030B...., that indicates 30 circuits and breakers allowed. It would indicate that there are no locations allowed for tandem breakers. My question is this: Are there times when this rule can be broken? Or have improvements in the design of tandem breakers since the manufacturing of the panel box allowed their installation in certain boxes or brands? I question it because I see so many installed in boxes that they apparently are not allowed, with no apparent problems, that I hesitate to mention it every time. I just want to get the issue correct and not create extra headaches for me or others involved in the transaction.

Jamie,

Check out this article below, on inspecting tandem breakers:

http://m.startribune.com/local/yourvoices/140688183.html

-Stay safe man.

I wouldn't break a "rule" given in the panel's instructions.

SheehanThomson wrote:I wouldn't break a "rule" given in the panel's instructions.

Agreed.