It's part of an AC unit - a heat pump to be more precise. This is a portion of the electrical diagram and I'm not familiar with this symbol: (that double diode seeming part in the box)

Greater overview of the diagram:

 

I'd go for plugged connection.

 

Interlock ? Check what plugs into CN1 itself on that display board.

 

There was a time when such a symbol was used on transistors to denote that they are Darlingtons (so expect to diode drops base to emitter). It may have been a dual diode.

 

I'm just guessing, but I suspect the "CN's" are connectors. CN 10 and CN 10A goes through that symbol to the display board CN 1. CN 32 likewise goes to CN 1. The unit is on the wall and would have to be disassembled in order to find out exactly what is connected in those locations. The only external connection to the display board from the main board is a single cable with small connectors on either end. The OPTIONAL components are just that - options that are not utilized at present.

I'm working with the HVAC installer to figure out how to control the temperature output via something other than the IR Remote. The remote will only go as low as 60˚ F (15.6˚ C), so I can't set the low heat temperature below that. I'd LIKE to set it as low as 45˚ but that's not possible via the remote. Perhaps via Wi-Fi or a hard wired controller will.

You may wonder why I want the low temp that low over night. This is a new woodshop. There is no plumbing. No water, no sewage. The only things in the shop I'd like to keep from freezing would be paints, stains and glues. No need to keep those above 60˚, no need to run that much electricity over night. A programmable thermostat can warm the shop at - say - 7:00 AM to 70˚. And in the summer time Cool the shop down to 70 in the morning, letting the natural temperature vary during the night. Via the remote I can not set ON / OFF times, so I can't just set it that way and forget about how cold it might get in there over night. The shop IS insulated, so overnight temperatures have not dropped below 40˚. But overnight temperatures have not fallen into the 20's yet. Those days are coming. And colder. Winters here can get down to and below zero degrees, but typically overnight lows see the teens and even single digit temperatures. Shop temperatures in the freezing can ruin paints and stains and stuff.

Back to this symbol: I don't know what it is. The optional wired controller connected to CN 2 would be a good starting place. I just don't know what that symbol is. I'm also wondering what the slash and number represent.

Anyway, thanks for your input. It's not important. Just curios I suppose.

 

Slash and number means that line path represents 5 conductors to the multipin connector CN2.

 

Slash and number means that line path represents 5 conductors to the multipin connector CN2.

That makes sense. Thank you.