On Sat, 11 Jul 2009 12:54:49 +1000, Tony wrote:

but MOVs can have vastly higher
ratings, and can also provide good lifetime when de-rated in lower energy circuits, so
they shouldn't be dismissed without proper consideration.

They certainly should if the originally designed in devices are
transzorbs, which every evidence says they are.

You also should examine the application. There will be a maximum
expected spike potential, and energy. The energy component of which is
pretty low. So big, monster MOVs is overkill, if you want to look at it
that way. Still points toward Transzorbs being the right choice.

Do you need to see it on a Silver Platter?