Mystery box on AC power supply

[IronWing]

I haven’t been up on the roof in quite awhile. When I got up there, I found an iPad and this black box attached to the power pedestal that feeds the AC unit. I charged up the iPad and that turned out to belong to the plumber we had here a few months ago. Any idea what the black box is?


I called the plumber and he is coming to reclaim the iPad.

 

[mindless1]

Hard to make out fine detail from that pic, does it have a brand or model or any other text on it?

First random guess would be either a fuse box or ammeter... except I don't know the details of the rest of what's in the pic, either. Is that a very low gauge power wire going into the side of it, that gray strip in the pic?

 

[IronWing]

The only marking on the box is a sticker marked C3-13 on the back. The gray strip in the background is the drain line for the AC unit that's been painted with roof coating. There are no exposed wires on the black box. It is plugged into the power box which has one big honking pull out breaker. Whatever the black box is wired to is behind the front plate. The system is 220V. I don't recall the black box being there when the system was installed. We had the system inspected a couple years ago and it may have been that long since I've been on the roof. The black plastic housing and exposed green LED doesn't look like something designed for permanent install.

 

[Greenman]

Surge arrestor?

 

[drnickriviera]

Surge arrestor?

looks like

Amazon.com

 

[IronWing]

I think that must be what it is. Thanks.

 

[herm0016]

yep. surge suppressor to protect the controls on the unit. we recommend them every time we do a service or put in large hvac units.