Tip #39: Wiring Basics
Electric wiring comes in two basic types, solid wire and stranded (many thin wires bound together by the insulation). Electricity tends to run along the surface of things, so stranded wire is much more efficient than a single wire of the same diameter. Single wires are stronger than stranded and are used in the heavier diameters.
The diameter of wire is measured by its relationship to the inch. #1 wire is one inch thick. The most common wire size for pump motors and lights is #12 or 12 wires to the inch, good for carrying up to 20 amps which is all the power you'll ever need for a residential installation.
Errant ends of splayed wire can make contact with other wires or metal objects which is never a good thing, and there are two ways to avoid this problem.
(top right) The wire terminal. This device contains a soft metal sleeve that, when compressed with a proper, color coded terminal wrench, keeps the multiple small wires together in the sleeve. The trick to properly securing terminals is to catch a bit of the insulation in the crimp, which makes the connection secure. Slide the female wire terminal over the male receiver every motor offers and you have a safe and long lived connection.
(left) The insulation collar. Ground connection on the typical motor is by a single securing screw. To keep stranded wire organized, use this old school trick: You will typically strip 3/4" of insulation from the end of your wire to make your connection. When you've done this, use your wire stripper (or razor blade) to cut another 1/8" of insulation and slide this collar down to the end of the wire.
This collar will hold the ends of stranded wire together even under the cruelest compression of a grounding screw.
Tip #40: D.E. Grid Spacing
The most efficient filter for a commercial pool is the Vacuum DE filtering system. It works by a pump pulling water through fiberglass grids set inside an open filtering tank . The cleaned water is then pushed back into the pool and dirt and filter powder are left in the filtering tank. (What most people don't realize is that the DE filter powder IS the actual filter. Everything else is just to keep the powder in place).
When you notice that one or two of the grids stay unusually clean, you can assume it's because they're not working.
The manifold is a 2" pipe with multiple, circumferencial, suction holes drilled for each filter grid. If the grid doesn't sit directly over these suction holes, it can't draw water.
Draw the water level down in the tank, exposing the grids. By health code, manifolds should be easy to remove. Hose the grids clean and set the array in the sun. Look down the manifold to find the suctions hole that don't shine with sunlight. These are the misplaced grids.
Pull the fewest grids it takes to get to and remove the misplaced grids. Measure the distance between the last plastic spacer and the middle of the exposed suction hole. Deduct 3/8" from this measurement and cut a slice of 2.5" pipe for a new spacer.
Drop your spacer over the manifold and slip the grid back in position.
Use the sunlight test to check your work
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