Whatever your local electrical inspector wants, and don’t even think of arguing with him or her!  I can tell you what is typical, but your local inspector can demand anything.

Generally, you’ll want a 20 amp 110 volt dedicated circuit with a Ground Fault Circuit Interrupter (GFCI), and a twist-lock outlet.  The outlet goes right next to the filter and the pool.  You’ll probably also need a copper ground wire around the pool, touching every vertical post – most pools have a screw at the bottom of the post to receive the wire.  The wire normally also goes to the ground screw on the filter, on to a bond in contact with the water (often in the skimmer or in the filter piping), and sometimes also to the ladder.  Then, the ground goes back to the house or right into the earth via a stake.  That water bond can be pretty pricy, and it’s a new regulation.  Electrical inspectors currently differ widely on what will make them happy.  Hopefully, your electrician has figured out what to use in your town – or ask the inspector.

The twist-lock plug is to keep you from using an extension cord someday – it’s very difficult to find twist-lock extension cords.  The inspector wants the plug that he or she inspected to be the only one that you’ll ever use.  Often, they will also require you to have a normal outdoor electric outlet between ten and twenty feet from the pool – though they normally won’t mind if you put it on the same circuit as the filter.  This is also a matter of trust – if you‘re going to use a TV, radio, or other appliance out there, they don’t want you to try to plug it in right next to the pool.

The ground wire around the pool is to protect the pool, equipment, and you from stray currents building up to dangerous levels.

Most of the filters sold inNew Englandwon’t even pass U.L. (Underwriters Laboratory) inspection, let alone the local electrical inspection.  Your electrician will probably have to apply some slight modifications to the filter before the inspection unless it is U.L. approved.