Originally Posted by
Bear
Top right on the top one has two switches with a clear casing around them. I've seen those switches discussed in some thread here that discussed them having a good amount of gold on some parts inside them, but I don't remember exactly which thread, or what it was all about
I can't be hundred percent sure because the pictures are a bit blurry but those things look like relays to me. I noticed them right away because I worked in Building Automation for 4 years and relays of that type are used extensively in Roof Top Air Handlers, Chiller Control boxes, and Variable Frequency Drives.
This type of relay is usually mounted to a block and have bladed contacts but I've seen them with pinned contacts mounted to older boards as in your first image.
These two pics show the gray block they are mounted to. The screws are where the high and low voltage control wiring connects. The upper tier screws are the low voltage control connections, the lower tier screws are for the high voltage wiring. You send a low voltage signal such as 24VAC to make and break the contacts to start and stop high voltage motors such as fans and pumps.
I don't recall this type of relay having gold plated contacts but I could be wrong.
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