This solar controller came in for recycling.

Notice the New Zealand mains plug used as part of the wiring.  This is potentially dangerous.  There is a possibility that it could be plugged into 230V AC mains power.  At best it would just blow up the controller and at worst it could electrocute someone.  These solar controllers only work up to about 20V.

This reminds me of the time I was repairing TVs back in the early 1980s.  Someone came in with a Pye Vidmatic portable colour TV (they were made by Sharp) that could run on 230V AC and 12V DC.  It had a mains plug on the 12V input.  The customer said he wired up 12V DC on his boat using mains plugs and sockets!  He said the TV would no longer work on 12V.  Funnily enough the 12V DC input fuse was blown!  It must have had 230V AC fed into the 12V DC input.

The lesson here is that the appropriate connectors should be used.  Mains plugs and sockets should only be used for mains voltages.