As I’m in the process of wiring everything in my observatory, I finally decided to make use of Anderson Powerpole connectors to connect up the DC power. These connectors are widely used for applications requiring high capacity DC power, originally (and still) used for ham radio rigs. The full range of connectors is available from PowerWerx, and here I’ll be using the most common 15/30/45A connectors (this is what people usually mean when they refer to Anderson Powerpole).

The connectors consist of a plastic housing which contains a stainless steel spring (more on that later) and a lug which is crimped onto the cable before being pushed into the housing. The housings have dovetails on the side which allow them to be joined together, usually in pairs, but in any number of configurations if you need more conductors.

Powerpole connectors are genderless (meaning both sides of the connection are identical, and you connect them together by turning one of them upside down) but polarized (meaning that once you have clipped together a pair of a positive and negative connector, they can’t be connected the wrong way round). These connectors are popular because they’re robust, high capacity, easy to connect up in the dark, and inexpensive.

The 15/30/45A connectors all use the same housing, but have different sizes of crimp lug that are crimped onto the wire before being pushed into the housing. I’m using the 45A connectors, because I’m using very heavy gauge cable (10 AWG) to minimize voltage drops; I’m going to have a few feet of cable between my control bay and the telescope, so I’m over-specifying the cables.

I have a bunch of cables that I’m making up, most of which are the heavy gauge 12V, but I also need a 5V cable to power a USB hub. There’s nothing substantial hanging off the hub that is USB powered, so I’m not really concerned about voltage drops for this one. I’m using a black and yellow convention for the connector housings in this case to distinguish from the black and red that I’m using for 12V; naturally Powerpole connector housings are available in many different colors.

Treating the side of the connector housing containing the spring as “down”, the lug needs to be inserted with the flat part at the bottom, as shown below.

Once the lugs are crimped onto the wires, they just push into the housing, and there should be a soft click once they are in place (more on this below). For smaller gauge wire, this should be no problem, but you definitely want to have a good quality crimp tool to compress the lug correctly, and you might need a pair of needle nose pliers to push the lug all the way in (the telephone pliers shown at left below are barely adequate for this, but will do in a pinch).

To check that the lug is inserted correctly, look at the front of the connector. The lip of the lug should overhang the front edge of the spring; if you don’t see it overhanging, it isn’t all the way in yet, and may come loose and will not make a good connection until this is fixed.

In the picture below you can see the spring, but no lug, in the black housing on the right, and at left, a correctly inserted lug with the lip overhanging the end of the spring.

Getting these correctly installed with thinner wires should be no problem, but is much more difficult with 10 AWG cable (the maximum size that the 45A lugs will support). If you are having trouble getting these to go all the way in, the likely culprit is the crush part of the lug enclosing the wires – that is, the part highlighted in red. Go back and crush this down some more – it might take a few tries, but the cable will not be reliable until this goes all the way in.

That’s it! Hopefully these will prove to be a good addition to the observatory setup.