As an electrician with over 15 years of experience, I've learned many obscure electrical techniques that most electricians are unaware of. These tricks of the trade can make electrical work safer, more efficient, and deliver better results. In this comprehensive guide, I'll share the top obscure electrical techniques that every electrician should know.
Using Saltwater for Cable Pulling
Pulling electrical cables through conduit can be a major pain, especially with long cable runs. The cable friction causes a ton of drag, making it nearly impossible to pull the wires through by hand. But there's an easy solution - using saltwater as a lubricant.
Here's how it works:
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Fill a bucket with warm water and mix in a generous amount of table salt. Stir until the salt dissolves.
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Soak some rags in the saltwater and wrap them around the cable you'll be pulling.
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The saltwater solution will act as a lubricant, drastically reducing friction as you pull the cable through the conduit.
This technique can save hours of difficult labor on big cable pulls. The saltwater lubricant allows the cable to glide smoothly through the conduit. Just be sure to thoroughly dry the cables afterward before making connections.
Using Magnets for Fishing Wires
Sometimes you need to fish electrical wires through finished walls and ceilings where there's no easy access. Rather than cutting huge holes and making a mess, you can use magnets to grab and pull wires through small openings.
Here's how I do it:
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Take a powerful rare earth magnet and tie it to the end of a string.
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Drop the magnet down into the cavity through a small cut hole. Move the magnet around to grab onto the wire.
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Once the magnet attaches to the wire, you can pull the wire back up through the opening.
This technique works great for grabbing wires through firewalls, floors, and ceilings. The magnet provides an easy way to retrieve wires without damaging the finished surfaces.
Using Your Voltage Tester as an Improvised Tone Tracer
When wiring a large panel with multiple circuits, it can be tricky figuring out which breaker controls which outlet or light. Most electricians use a tone and probe tracer, but you can also improvise with just your voltage tester.
Here's how to trace circuits using a voltage tester:
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Start by turning off all the breakers in the panel.
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Turn on the breaker for the circuit you want to trace.
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Go around the room and touch the hot terminals in each outlet with your voltage tester. When it lights up, you've found the outlet on that circuit.
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Make note of the outlets that are hot to identify all locations on that circuit.
This technique comes in handy when you don't have access to a dedicated tone tracer. Just be sure to only touch the hot terminals with the tester and not place it inside the outlet slots.
Using Aluminum Foil to Find Breaks in Wires
Trying to find breaks in damaged or corroded wires can be extremely frustrating. But you can easily pinpoint wire breaks using some aluminum foil and tape.
Here's how to do it:
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Clean the wire you want to test by gently scraping away any corrosion.
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Wrap the wire in a strip of aluminum foil, covering about 6 inches of length.
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Secure the foil tightly to the wire using electrical or duct tape.
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Use your multimeter to check for continuity by touching the probes to opposite ends of the foil strip.
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As you slide the foil down the wire, at some point continuity will be lost, indicating the precise location of the break.
The aluminum foil bridges the damaged section of wire, making it easy to locate the break point. This simple technique has helped me troubleshoot many pesky open circuits over the years.
Shielding Sensitive Circuits from EMI with Mumetal
Electrical devices like sensors, transmitters, and controllers can malfunction or act erratically when affected by electromagnetic interference (EMI). Shielding these circuits from EMI can be challenging.
An obscure solution is to build an enclosure from Mumetal - a special nickel alloy that blocks electromagnetic and radio frequency signals.
Here's how effective Mumetal shielding works:
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Fabricate an enclosure from thin Mumetal sheets to house the sensitive circuit.
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Use Mumetal gaskets around access panels to block EMI leakage.
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Bond all seams and joints together electrically.
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Ground the enclosure to earth or system ground to dissipate interference.
Mumetal boxes provide up to 100dB attenuation of troublesome electrical noise caused by EMI/RFI. This obscure metal alloy is a great alternative to traditional steel and aluminum enclosures when shielding EMI-sensitive circuits.
Identifying Live Wires Inside Walls with an AM Radio
Trying to figure out which wires are live inside a wall cavity or junction box can be tricky - but you can easily identify energized wires using an AM radio.
Here's how it works:
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Tune an AM radio to a frequency on the low end of the band where no station comes in clearly.
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Turn the volume up halfway.
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Hold the AM radio next to each wire inside the junction box or wall cavity. Live wires will emit a buzzing sound through the radio.
The electromagnetic fields around current-carrying conductors induce signals in the AM radio. This obscure technique allows you to definitively detect live wires without removing wire nut connections or using a meter. It's especially handy in crowded junction boxes with lots of wires.
Getting Rid of Cable Aluminum Oxidation with Coke
Aluminum-bodied cables like SEU and SER often suffer from surface oxidation, which increases resistance and can cause power losses. Removing the oxidation chemically is difficult, unless you use Coca-Cola.
Here's how Coke removes stubborn aluminum oxidation:
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Soak a rag in standard Coca-Cola - don't use diet or zero versions.
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Wrap the Coke-soaked rag around the oxidized aluminum cable. Make sure the coke penetrates and wets the oxidation.
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Let it soak for 5-10 minutes. The phosphoric acid in Coke will react with the aluminum oxide.
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Wipe down the cable. The oxidation should scrub off easily, exposing clean metal underneath.
While it sounds crazy, the citric and phosphoric acid in Coca-Cola does a great job dissolving metallic aluminum oxidation. This unusual technique can restore optimal electrical contact on oxidized cables in a pinch.
Wrapping Up
Mastering obscure electrical techniques like these will make you a better, more versatile electrician. From wire pulling tricks to corrosion removal, these tips and tricks can save you substantial time and effort on the job. Knowledge of these lesser known methods separates the electrical pros from the amateurs.
So next time you run into an unusual electrical challenge, don't be afraid to think outside the box. Try one of these obscure techniques - you might just surprise yourself with how well they work! Let me know in the comments if you have any other obscure electrical tricks I should know about.