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NORA Oilheat Technicians Manual

8-28 Basic Electricity Twist Cut Here Clockwise Snip and Remove, Trim Sharp Ends Figure 8-29: Cutting armored cable Chapter 8 Basic Electricity Bend and Squeeze Bonding Strip Bushing Basic Concepts about Electric Circuits • Electricity must have a complete path from an electrical source through a load and back to the source. • Conductors offer less resistance to electric current than insulators. • Voltage is the electrical pressure difference between two points in a circuit that causes electricity to flow. • Current is the rate of flow as measured in amps. • Resistance is the opposition to flow measured in ohms or pressure drop. • A load offers resistance to an electrical current. It determines the current draw for any voltage applied. • The load will only draw enough current to overcome that resistance. • Voltage applied is voltage consumed. • It takes one volt to push one amp through one ohm. Grasp the cable firmly on each side of the break and twist the waste end clockwise until the armor comes apart enough for you to slip in cutters. If you have trouble doing this with your hands, use two pairs of pliers. Cut through one rib of the armor with a pair of side-cutting pliers. Slide the waste armor off the wires. Remove the paper wrapping and plastic strips. Leave the thin metal bonding strip alone. Use side-cut pliers to trim away pointed ends of the sheathing that could nick a wire. The next step is to slip the plastic bushing over the wires. Slide it down into the armor so it protects the wires from the sharp edges of the armor. If there is a bonding strip, cut it to about two inches and wrap it over the bushing and around the armor to ensure conductive contact between the armor and the box. Option: If you plan to do a great deal of wiring, you might want to buy an armored wire cutter to speed up this job. Now attach the clamp (connector) to the cable. Remove the lock nut from the armor cable clamp and slide the clamp down over the bushing as far as it will go. Then tighten the screw. Finally remove the knockout from the junction box, and poke the wire and connector into the hole. Slide the locknut over the wires, and thread it onto the cable clamp. Use a hammer and screwdriver to tap the locknut tight.


NORA Oilheat Technicians Manual
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