Popular Woodworking 2005-10 № 150, страница 87

FIGURE B: Here is an example of the 120V/240V wiring for a two-gang box. Leave at least a foot of cable in the box to allow for the accordion folding so the receptacles can be easily connected to the wires and then pushed into the wall box.

A single cable provides

120-volt and 240V service.

three-wire cable provides dual 120V 20-amp circuits to round out the shop installation. These principles can be extended to multiple machine circuits, including automating the dust collector. (See "Easy Automatic Dust Control" on page 85.)

If the 120V receptacles are located in an unfinished space (garage or basement), the National Electric Code requires ground fault circuit interrupter (GFCI) protection. You should check with your town's wiring inspector to see if your specific shop space requires GFCI receptacles. If it does, you will need a GFCI receptacle for each 120V outlet. If GFCI-protected 120 V circuits are required, it may be more economical to run separate, conventional two-conductor circuits; one for 240V and one for 120V. The 120V circuit can then be protected with a single GFCI breaker and employ conventional receptacles. In that case you may want to use separate wall boxes for each voltage to reduce the wiring load in a box.

Component Selection

Heavy-duty commercial, "spec" or industrial-grade duplex receptacles should be used for shop applications; avoid residential or contractor grade units. Duplex receptacles rated for 20 amps at 125V are readily available. But 250V, 20-amp receptacles commonly found at home centers only have single outlets. Duplex 250V, 20-amp receptacles are available, but you will probably have to go to an electrical supply house to obtain them.

Duplex receptacles provide twice as many outlet connections with no extra work so are well worth the effort to locate. Like clamps, you can't have too many outlets. The Leviton No. 5462 is a duplex 250V, 20-amp receptacle available in brown or ivory. You will also need 250V male plugs for your machines. These are available at home centers, and come in 15- and 20-amp versions, which have different pin shapes, but either plug will insert into a 20-amp receptacle. I recommend the 15-amp plug for maximum flexibility. You might also want

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