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Mr. Electrician

Licensed Electrical Contractor
Wires in a hole awaiting the installation of an electrical box

Installation of an Additional Wall Dimmer and New Ceiling Light Fixture

Dear Mr. Electrician: Is it possible to install an additional dimmer next to an existing one and connect a new ceiling light to the new dimmer? Answer: Yes. However the methods used to achieve this type of installation will vary according to your building structure and the location of the switches and light fixtures. Below are photos of a simple dimmer and ceiling light installation in a condominium.
A very old style of GFCI receptacle.

Testing and Replacing a GFCI Electrical Receptacle

Dear Mr. Electrician: I push the "Test" button on my bathroom GFCI (Ground fault circuit interrupter) receptacle occasionally, but nothing seems to happen. How do I know if the GFCI receptacle is working properly? Answer: By pushing the "Test" button a simulated ground fault of approximately 6 milliamperes is shorted across the internal conductors and should cause the GFCI (Ground fault circuit interrupter) receptacle to stop working immediately. Normally you would hear a mild click sound and the "Reset" button might pop out a little. If the GFCI is not deactivated after pushing the "Test" button, the GFCI receptacle should be replaced as soon as possible because you are no longer protected against an electric shock or electrocution. Pushing in the "Reset" button should reactivate the GFCI receptacle. I have found that some "Reset" buttons need to be pushed in firmly using a blunt tool such as a screwdriver. Another method that I also use to test a ground fault circuit interrupter receptacle is with my Ideal Voltage Tester. I put one prong from the voltage tester into the ground pin opening and the other prong into the neutral side of the receptacle which should always be the larger slot. That usually trips the GFCI if it is working properly. If it doesn't trip, replacement is called for.  Unfortunately the new tamper resistant receptacles prevent me from testing this way so I use my plug-in tester instead. To replace the ground fault interrupter receptacle you should begin by shutting off the power to that particular circuit at the main circuit breaker panel or main fuse panel. Test the receptacle with a lamp, radio, or an electrical tester to make sure that the GFCI receptacle is without power. This may not be totally effective as it is possible that a non-working GFCI receptacle may not have power available regardless. Therefore you should proceed to the next step with caution and test the actual wires at the screw terminals of the GFCI receptacle using a voltage tester, a voltmeter or a pigtail light socket with a lightbulb. Remove the GFCI receptacle cover by unscrewing (Counterclockwise) the upper and lower screws on the cover plate. Next unscrew the upper and lower screws that secure the receptacle to the wall mounted electrical box. Carefully pull the GFCI receptacle straight out of the box as far as it will go. Take note of the wires connected to it. Look at the new Tamper Resistant GFCI Receptacle that you will be using to replace the old one. On the back you will see some words stamped into it. "Line" and "Load" are what you need to take notice of. Look at the back of the existing GFCI receptacle and take notice of which wires are on the "Line" and "Load" terminals. Normally the wires are white and black. Black on the "Line" side would be the hot wire that feeds into the receptacle. The white wire on the "Line" side is the neutral conductor that provides a path for the...
Bad Grounding for Telephone, TV, and Power

Grounding and Bonding For TV and Telephone

Dear Mr. Electrician: My neighbor was blown out of her chair when lightning hit her TV.  How can I prevent that from happening to me? Answer: Basically everything needs to be properly grounded and bonded in such a manner as to provide a good direct path for lightning to flow to the earth. The photos below depict an actual job of mine correcting the grounding for a 1940's single family detached house. Article 250 in the National Electrical Code concerns grounding and bonding. Some relevant sections are: 250.8, 250.52, 250.90, 250.94, 250.104. Also read article 800.100 on grounding communication circuits and 820.100 which concerns the grounding of cable TV systems. For more information on steps that can be taken to improve lightning protection, please read NFPA 780. For another article by me on the topic of grounding, click here  
A Water Pipe Ground Clamp Attached Where the Pipe Enters the Basement

Grounding Electrode System

Dear Mr. Electrician: I recently hired an electrician to fix something in my very old house.  He told me that the electrical service to my house did not have a good grounding electrode system and gave me a ball park price to fix it up.  Why do I need this and what is involved with fixing or installing a grounding electrode system? Answer: The primary function of the grounding electrode system is voltage stabilization and lightning protection.  The grounding electrode system consists of a wire or two that originate on the grounding terminal in your main electrical panel or disconnect switch.  From there the wire(s) will connect to the home's water pipes and to one or more grounding electrodes.  The grounding electrodes can be ground rods, concrete encased rebar, copper plates, copper wire in the footings. concrete embedded steel or other means that provide an approved electrical path to earth. The main grounding electrode connection for many houses is at the metal water pipe at the point where it enters the home before the water meter.  Look at this area and you should see a copper or aluminum wire; bare, insulated, metal armor jacketed, enclosed in conduit, or taped green. It should be connected to the water pipe using an approved ground clamp usually of bronze construction.  The connection should be tight and free of corrosion. If the ground clamp and wire appear corroded or feels loose you should remedy this right away. A new ground clamp costs only a few dollars and can be purchased at any electrical supply company and at many home improvement stores. You will also need some emery cloth or sandpaper to clean the pipe.  A good precaution when doing this would be to shut off the main circuit breaker or pull the main fuse in your electrical panel.  It is possible that a tiny amount of current may be traveling over your grounding conductor.  I also suggest wearing gloves and avoid touching the bare wire and the water pipe at the same time. If your home gets its water supply from a private well or through a plastic pipe, your primary ground connection should be a ground rod or two.  In many cases the ground rod(s) are completely buried and therefore are not easy to inspect.  According to published data, a copper plated ground rod can have a life expectancy beyond 40 years.  However I have found when working on customers homes, loose ground rod clamps, incorrectly installed ground rod clamps, cut grounding electrode conductors, ground rods that have been damaged from landscaping and construction excavation, and galvanized pipes driven in the earth instead of an approved ground rod. Something to consider at this time is upgrading your grounding electrode system to the latest "National Electrical Code" requirements.  The current code requires that new installations have at least one supplementary ground rod installed and to also have all interior metal piping connected (Bonded) to the grounding electrode system. In some jurisdictions the requirement to bond the interior gas pipes...
The Backside of a Residential Telephone Jack

Telephone Wiring Color Code

Tip + Ring - Cat 3 Green Red Cat 3 Black Yellow Pair 1 White with blue stripe Blue Pair 2 White with orange stripe Orange Pair 3 White with green stripe Green Pair 4 White with brown stripe Brown  
Front and Rear of an Old Style Pancake Box for Knob and Tube Wiring

Replacing a Very Old Style Ceiling Electrical Junction Box

Dear Mr. Electrician: I want to replace a very old ceiling light fixture in a very old house. After removing the existing light fixture ceiling canopy cover that hides all of the wiring, I found that there isn't a standard ceiling electrical outlet box. Instead, there is a black round disc (about 3 inches in diameter) which has a 1 inch long screw type rod sticking out of it. The wires are around it.  The light fixture that I want to install comes with a flat hanger bracket and the instructions tell me to install the hanger bracket onto the outlet box. Since there is no outlet box, I don't know what to do. What are my options? Answer: I suspect that the round disc is actually an old black enameled metal pancake box.  It's approximately the diameter and thickness of a hockey puck and made out of metal.  Sometimes an old gas pipe protrudes from the middle of this pancake box instead of a fixture stud.  A setscrew tightens the box to the gas pipe. (adsbygoogle = window.adsbygoogle || ).push({}); That was how old houses that originally had gas lighting converted over to electric lighting.  The pancake box was mounted onto to an existing disconnected gas pipe.  The cables were attached to the pancake box and splices were made.  An additional fitting or two was threaded onto the gas pipe to support the light fixture which was made for this type of installation.  The canopy of the old style ceiling light fixture acted as the junction box for the spliced wires. Other types of old pancake boxes were mounted directly onto ceiling joists using wood screws.  Instead of an opening for a gas pipe, they would have their own fixture stud for attaching a light fixture to.  The fixture stud had the same size thread as a gas pipe of the same diameter. Around the pancake box are four holes, each with a setscrew or clamp which engages the cable, preventing it from being pulled out, and provides electrical continuity for the equipment ground for the armored cable. The wiring is most likely armored cable (BX).  However ungrounded non-metallic cable (The Type Before Romex), or knob and tube type wiring is possible as well. Beware if the gas pipe has a cap on it. Usually the caps are removed when the gas line is taken out of service.  However, until you can verify that the gas line is dead you should not remove the cap. In a situation where the original wiring insulation has degraded, the best thing would be to install new wiring.  However that not only could be expensive, but damaging as well.  Walls and ceilings may need to be broken open to re-route or remove old dried and brittle cables and install new wiring. Turn off the power. You will need to remove the old pancake junction box.  Do it carefully so as to not damage the existing wiring.  Often, wiring from that era of home construction now has dry, brittle insulation...
The existing 2' x 4' fluorescent kitchen light fixture

Recessed Lighting in a Condominium Kitchen

Dear Mr. Electrician: I would like to replace the existing fluorescent light fixture in my condominium kitchen.  How difficult is it to install recessed lighting in a condominium and will it make a difference in appearance? Answer: The most challenging aspect of installing retrofitted recessed lights is the measuring and laying out of the location for each light.  With a finished ceiling there is no simple way of knowing what obstacles might be in the way of your light installation.  Therefore you must probe the ceiling ahead of time to see if there are any utilities where a light was planned.  Something to be mindful of is the fire rating of the ceiling if there is another condominium above yours.  Remodeling type recessed lights are usually not fire rated.  An alternative would be to install surface mounted LED disks on the ceiling which have a similar appearance to recessed, but mount directly onto a standard round electrical box.  Below are some photos of a recessed lighting installation in a condominium kitchen.
Universal Motor Wiring Diagram

Fractional Horsepower Electric Motor Diagrams

Wiring Diagrams of Fractional Horsepower Electric Motors Split Phase Induction Split Phase Permanently Connected Capacitor Split Phase Capacitor Start Split Phase Capacitor Run Another Split Phase Capacitor Run Split Phase Capacitor Run Induction (Reversible) Reactor Start Split Phase Single Value Capacitor (Dual Voltage Type) Repulsion Repulsion Start Induction (Reversible) Shaded Pole Skeleton Type Shaded Pole Universal    

Aluminum Wiring

Dear Mr. Electrician: I am planning to have the electrical service to my house upgraded and the licensed electrical contractor that I am using told me that he will be installing aluminum wire for this.  Is aluminum wire safe to use? Answer: Yes it is safe to use aluminum wire for new installations and for upgrades.  Aluminum wire does have a questionable past, and problems still occasionally surface to this day from improper installations that date back to the 1960's and 1970's.  However new types of wires, wiring devices and equipment with an aluminum wire approval have all been tested to be safe.  Click here to read "Aluminum Building Wire" published by Southwire. If you own a house that was built in the 1960's or 1970's and it was wired with aluminum wiring throughout, there is no need to panic. However you will need to take some steps to be sure that the wiring is currently in good operating condition and is properly installed. It is possible that a previous owner took the necessary precautionary measures, but you have no idea if they were done correctly unless you investigate. The simplest thing to do is to have a look at your electrical switches and receptacles from inside. This entails removing them from the wall with the POWER TURNED OFF. This must be done very carefully where aluminum wire is installed. The old aluminum wire does not have the flexibility of copper. Consequently it can break very easily upon the removal of a wiring device from the wall and make matters worse. If you are not comfortable with doing this, please call a licensed electrical contractor to have a look. The correct procedure to make your existing aluminum wiring safe at every electrical receptacle and switch is to pigtail the aluminum conductors with copper wire. This can be accomplished using one or more methods. The best and most recommended technique is called the Copalum method. Basically it is a specifically designed crimper for aluminum conductors. It uses a crimp sleeve designed and approved for use with this tool and for the aluminum wire to copper connection. Unfortunately the Copalum method is proprietary and the user must be trained and licensed by the manufacturer to use the tool and purchase the necessary supplies. Consequently you must call a licensed electrical contractor who has been factory approved to do the necessary corrections to make your wiring safe using the Copalum method. Not all electrical contractors have taken the time to get approved to use the Copalum method so it may take several phone calls to find someone to do the work. Another technique is to use twist-on aluminum wire connectors that are specifically designed for aluminum connections. I think that connecting stranded copper wire to the aluminum wire is the best because it allows more flexibility for installing a wiring device and puts less strain on the aluminum conductors in the process. The aluminum wire connectors are more expensive than standard twist-on wire connectors, but they are tested and approved for the...

Generator Sub-Panel Installation

Dear Mr. Electrician: I want to have a portable generator connection for circuits in my house such as the furnace, the sump pump, and the refrigerator.  How can I install this? Answer: One simple installation is a stand-alone generator sub-panel for some previously selected circuits to be powered when the generator is on.  Below are photos of a generator sub-panel installation with a PB-30 generator inlet.  Some of the applicable articles from the National Electrical Code concerning the installation of generator sub-panels are: 210, 230, 250, 300, 310, 314, 334 and 702. You can see photos of an interlock kit installation on a Cutler Hammer Load Center here.