Electrical Module Section 3

INSPECTION TECHNIQUES AND METHODOLOGIES

Now that we have learned some basics about electricity, it’s time to examine the electrical inspection process for residential settings.

NOTE: The most common wire sizes the Inspector will encounter in a residential setting are #14, #12, and #10. Be advised that copper and aluminum wires will most likely be observed. In some instances, what may appear to be aluminum wiring could be seen, but in reality it may be tinned copper wiring. The only way to determine if this wire is not aluminum would be to remove a conductor, and scrape some of the tinning away, which would reveal the copper core. This would exceed most inspection Standards of Practice, including InterNACHI’s, and is not recommended.

ELECTRICAL SYSTEM INSPECTION: Where to start.

The following information is for illustrative purposes only. It touches on many items which should be examined during an electrical nspection. It is not meant to be technically exhaustive or all inclusive. Nor is it meant to suggest that the sequence depicted is the only way to perform an electrical inspection.

INSPECTING EXTERIOR ELEMENTS:

Depending upon where the house is geographically located, and when it was constructed, the Inspector could encounter differing electrical installation methodologies, materials, and standards.

DROP WIRES AND SERVICE CONNECTION POINTS

The first items for the Inspector to examine will exist on the home’s exterior. First, it is important to establish the path the utility company, or electrical supplier, took to deliver power to the dwelling. In many cases the cables come from a utility pole, via overhead (aerial) routing. Examine the number of cables present. If two wires are present, the dwelling most likely is powered with 110 or 120 volts of alternating current (AC. Where three (3) wires are present, the home is most likely powered with 220 or 240 volts of alternating current. The three physical cables bring in 1110 or 120 volts between each hot leg, and ground. The combination of the two legs equal 220 or 240 volts.

The next item to examine is the physical connection to the structure. The cables should be securely anchored, and a weather-head should be present. Electrical cables should also physically loop upwards to the weather-head. From this point, examine how closely these cables are physically located to any window. Height is also important, and the minimum height to the earth should be 10’, and a minimum of 12’ if above a driveway.. They should also not be within 3’ of any window.

Examine the service drop wire next. This is the cable, which extends from the weather-head to the electrical meter. In some older installations, the meter may exist on the interior of the dwelling. Other installations include electrical meter and pan located on te home’s exterior. Carefully examine the exterior of the cable for signs of wear, including fraying, cracking, or the appearance of individual conductors. The cable should be smooth and intact. Even older cloth wrapped cables should be intact. If not, it may need replacement. Examine the entry point to the top of the meter. It is properly sealed to prevent moisture intrusion? If not, note it, as it is a defect. Examine where the cable protrudes from the meter pan, and continues to the homes interior or to the main electrical panel. On the West Coast, it is relatively common to see this panel on the home’s exterior, while in the Midwest and East, installations on the home’s interior are more prevalent.

Some dwellings are fed via underground conductors, known as service laterals. In these instances, examination of the conductors will be limited.

This cable s referred to as the service entry cable, and it, too, should be relatively smooth and intact. If the electrical panel is on the home’s exterior, make sure it is rated for outdoor use. 

INTERIOR ELEMENTS OF COMMON ELECTRICAL SYSTEMS

THE MAIN ELECTRICAL PANEL
Examine the panel, whether interior mounted, or on the exterior. Look for signs of rust, or burn marks. Look for excessive moisture, loose or protruding wires, missing screws, or any other sighs that there may be problems lurking. Your life may depend on it.

With a voltage detector, or Tic Tracer, check the panel cover and casing for signs of voltage. DO NOT touch the panel before ensuring that the box or cover is not energized with stray voltages.

Ensure that you are wearing appropriate Personal Protection Equipment (PPE) before proceeding. Open the panel door, and look for a main fuse or circuit breaker. Older fused panels utilized main cartridge-style fuses on the entry, while modern panels use a conventional main circuit breaker. Regardless, either should be marked as “Service Disconnect”.

Note the size of this breaker or fuse. It will be marked as 60, 100, 150, or 200 in most instances. Older homes were sometimes equipped with 60-amp service, but with the popularity of modern appliances, such as dishwashers, air conditioners, electric stoves or ovens, computers, and so on, 60-ampere installations may be inadequate. As such, a minimum of 100 amperes is recommended, with a trend towards 150 or 200-amperes as the emerging standard. Houses which have only 110-120 volt main services are underpowered, and a service upgrade, with new meter, pan, and main panel should be recommended. This is due to the fact that most major appliances, such as central air conditioning units, electric heat, electric clothes dryers, and electric ranges use 220-240 volts.

Next question: Is the panel properly marked? Are all branch circuits properly identified? It should be.

The following section needs to be carefully read, and the Inspector should use
extreme caution before proceeding. Removing the dead front cover of electrical panels is necessary in most cases, to examine how the individual branch circuit conductors are connected, and to help determining the condition of the panel and wiring. This is one of the most hazardous actions the Inspector can take during the inspection process. EXTREME CAUTION must be taken at all times.

Close the panel cover and carefully remove the panel screws. Place the screws in a safe location, and carefully remove the panel cover. Place the panel cover out of reach, and proceed back to the panel. Under no circumstances should anyone place their hands or any object inside the electrical panel. Electrocution can easily result.

Examine the service entry conductors. Try and determine of they are the proper size for the amperage rating of the main breaker. They can be rated HIGHER than the breaker, but NOT lower. Simple plastic gauges are available to assist with this process. Use extreme caution when around any live conductor. Electrocution can occur. Examine the condition of the cables, and the manner of connection. Also examine the position of the main breaker. “On” should always be “Up”. Some manufacturers mount the main breaker sideways, which is also acceptable. Many times, the main conductors will be made of stranded aluminum cabling. If this is the case, be sure and look for the presence of anti-oxidizing compound at the main terminal lugs. It is a black, greasy appearing substance, and should be present on aluminum connections, unless the panel is properly rated for connections absent of this compound> these panels typically have markings indicating whether it is rated or not.

Look at the panel’s overall rating. If it is equipped with a 200-ampere main breaker, make sure that the panel is rated for it.

Count the number of breakers in the panel. A good rule of thumb to remember is 20 breakers for 100-amp service, 30 breakers for 150-amp service, and 40 breakers for 200-amp service.

ONE BIG PARALLEL CIRCUIT

In the previous section, we spoke of series and parallel circuits. Ths is an important concept to grasp. If you look at the physical construction and connections to an electrical panel, one can see that it is a big parallel circuit. Although individual circuit breakers control a branch circuit, all breakers share common electrical paths. The circuit breakers attached on the left side of the panel are all commode to one hot feed leg, while the breakers connected on the right side share the 2nd hot leg.

With all parallel circuits, Ohm’s law comes into play. Every branch circuit has some resistive value when a device or appliance is attached to it. Each successive device connected n parallel reduces the overall resistive value, as it is connected in PARLLEL. As resistance drops, current flow increases. This is why connecting too many devices to a circuit can overload it. Considering that circuit breakers will trip at a sustained draw equaling 80% of the actual rating, this helps explain how and why breakers trip or fuses blow.

As we stated, not only are individual devices connected to single branch circuit wired in parallel, so then are multiple breakers. As each branch circuit is connected to the power bus behind the breakers, the overall resistance of circuits connected to the panel also decreases. This allows the current needed to feed all these circuits to increase. This helps to explain how and why the panel functions.

GROUND SOURCES

Next, examine the grounding sources. The panel will have a grounding conductor supplied from the power company. It is typically un-insulated and is stranded. It may connect to the neutral bus bar in the panel. There should also be a secondary wire connected to this same bar. It will likely trace back to the water meter. On older installations, this cable would attach to the street-side of the water meter. Current installation practices have a connection to BOTH sides of the water meter. Look for a third cable. This may be connected to a driven ground rod.

Other installation practices include bonding the hot and cold water sides of the water heater to each other, and bonding any metallic ductwork in the home to ground. These are more modern practices, and may or may not have been an Electrical Code requirement at the time the home was constructed. This would be the difference between a defect and a recommended upgrade or improvement.

Next item would be to examine the inside of the main panel. Look at the bottom of the panel interior. Is it wet or rusted? How about the circuit breakers? Are there any signs of rust colored powder or streaking in the vicinity of the breakers? If so, it may be an indication of water intrusion. This would be a significant find, as water is an electrical panel’s enemy. Where any of these conditions exist, it is sometimes best to call for further evaluation by a licenses electrical contractor.

RULE OF SIXES

There is something known as the Rule of Sixes, which simply means that an electrical panel must be able to completely de-energize all branch circuits with the throw of a hand, or no more than 6 individual circuit breakers. This is the reason for main disconnecting fuses or breakers. If there are more than 6 breakers present in a panel, and the panel has no main disconnect fuse or breaker, it is considered a defect. Condominiums, homes, and apartments with the main disconnect on the exterior, do not require a main disconnect in the panel, as it can be disconnected at a main location before building entry.

DOUBLE TAPS

Next, look for circuits which utilize a common neutral and ground conductor. This is where a single physical cable s used to feed two branch circuits (2 circuit breakers involved. This is accomplished where a 3 conductor with ground cable is utilized. One conductor, which is usually black, is connected to a circuit breaker. Another conductor, which may be red, is connected to an adjacent breaker. The two circuits share a single common neutral conductor, and a single ground conductor. The danger in circuits wired in this fashion is in the fact that, when one of the circuit breakers is de-energized, the neutral conductor is still carrying current from the send, still energized, circuit. There should be a common trip mechanism, between each breaker, which is connected in this fashion.

ALUMNUM BRANCH CONDUCTORS

In much older homes, the Inspector may encounter knob and tube  (K&T) wiring. This older methodology utilized electrical cable, which was run through, porcelain attachment knobs and looms, attached to, and through structural components of the building. This wiring is pretty easy to identify, as it looks quite different than all other types of electrical wiring you will likely encounter. Some of these older installations are in working order, while many others are not. Should you see this type of wring in a home, use a Tic-tracer to try and determine if the conductors are energized. Examine the condition of porcelain insulators. Look for cracks or broken pieces. See if they are properly secured. Examine the conductors. Look for cracks in the insulation. Any signs of fatigue should be noted. Where this wire passes through wooden members, there should be a ceramic sleeve present, which the physical wire passes through. Pay particular attention to areas where K&T transitions to other cable types, such as metallic and non-metallic sheathed cabling. Many insurance companies are reluctant to underwrite dwellings with this type of wiring, and for good reason, so use caution during the entire inspection process. When in doubt, don’t hesitate to recommend further evaluation by a licensed electrical contractor.

CABLE ROUTING OUTSIDE THE PANEL

Next, examine how the branch cables are routed. Are they neat, or does the installation resemble a rat’s nest? This may be an indication whether a licensed professional did the installation, or an unqualified individual. It may also be an indication as to whether any electrical work was properly inspected, as many inspectors do not want to see a tangle of wires. Make sure the cables are properly supported. Examine how they are run through structural elements. Look for hanging wires, with extra slack.

CRAWLSPACES AND OTHER CONFINED AREAS

Should the home have a crawlspace, or any other confined space, use EXTREME CAUTION when entering or inspecting. Follow OSHA guidelines and your own common sense. In many of these areas, electrical cables may be fatigued or can be otherwise damaged. If the space is exposed to high humidity, and armor sheathed cables are installed, the sheathing can be rusted, jagged, or broken. Junction boxes could be open or uncovered, and live wiring exposed. The inspector will likely be crawling, or on his/her back, and be in full contact with earth. Should a human come in contact with energized wiring under these conditions, there could be grave consequences. An inspector should NEVER enter a wet crawlspace.

JUNCTION BOXES

Look for uncovered junction boxes. This is a common defect. Look for unclamped cables, which enter these boxes through raw and open knockouts. There should be a clamp or grommet present at each penetration. Look for junction boxes with uncapped conductors, or which are overloaded with wires. Look for wall switches and receptacles with no covers. Look for loose, protruding, or unsecured wall switches and receptacles. Pay particular attention to these elements in unfinished garages and basements. Many times, homeowners install lighting fixtures in these spaces. Though many are installed in a quality manner, many are not. Be sure and look at the connection and mounting methodologies.

2 AND 3-PRONG RECEPTACLES

Pay attention to whether the home may have been originally equipped with 2-prong or 3-prong receptacles. If it is equipped with 2-prong units, ensure that the branch cables are equipped with 3 conductors (hot, neutral, and ground). This will typically indicate whether the receptacles can be upgraded. Remember, if the branch cables are metallic sheathed, the ground will be extended from the electrical panel to the receptacle box via that metallic sheathing.

Two prong receptacles should be the polarized type, with one slot being larger than the other. If not, most modern 2-prong electrical cords will not fit in the slot. Should 2-prong receptacles be present, the Inspector may want to check to see if the receptacle is grounded. An easy way to do this is to turn the power of to the receptacle, and with a multi-meter set to continuity, touch one lead to the center screw of the receptacle cover, and the other to a cold water pipe. There should be continuity, with little resistance. If not, there may be serious problems, as the system may not be grounded.

WALL SWITCHES

If wall switch handles feel loose, they may be fatigues to the point of needing replacement. “Feel” activated dimmer switches to try and determining if they get warm or hot. Of they do, they may be defective.

GFCIs      (GROUND-FAULT CIRCUIT INTERRUPTERS)

Be sure and test all GFCI receptacles ad breakers you observe. Follow the manufacturer’s recommended testing procedure.

In newly constructed homes, look for GFCI’s in all basement, garage, exterior, bathroom, whirlpool, kitchen island, and kitchen counter locations. Recommend that they be installed n these locations, even in older homes. In older homes, absence of these devices may not be considered a defect (depending on the age), and would be considered a recommended upgrade. Of course, and non-functioning GFCI would be considered a defect, regardless of the age of the home. In some instances, where electrical receptacles are ungrounded, GFCI’s can be installed. It does not provide a grounded system, but can provide some limited protection. Contact a licensed electrician for advice and recommendations, or for further evaluation.

In bathrooms, switches and receptacles should not e located next to tubs or showers, where a person standing in the shower can touch the switch or receptacle.

FIXTURES, RECEPTACLES, AND SWITCH CONTROLLED DEVICES

Observe all permanently installed lighting fixtures. If a hanging chandelier is noted, ensure tat the wiring is intact, with no visible cracks or splices. Turn on as many light switches as possible. See if they activate something. If the homeowner is present, and nothing activates, be sure and ask what the switch controls. Note any that may not function or are marked “do not turn off” or “do not turn on”. Note three way switches. Lighting controls for stairwells should control the lights via switches located at the top and bottom of the stairs. Operate all permanently installed appliances. Test a representative number of electrical receptacles. If 3-prong receptacles are present, test with a simple receptacle tester for ground, reverse polarity, etc. Be sure and note if receptacles are installed above electric heating units (baseboards) in rooms. There are rules associated with these installations. Look for a GFCI where whirlpool tubs are plugged in. If none is present, look for a centrally installed GFCI in the electrical panel. Protected receptacles should be marked as such.

Be sure and note if outlets and switches are not accessible, or are blocked by furniture.

EXTERIOR LIGHTING

Examine exterior lighting fixtures. Make sure that they are securely mounted, and properly affixed to prevent rainwater or runoff from entering in or behind the fixture, itself.

Look for tripping hazards, especially with low-voltage landscape lighting.

ELECTRIC WATER HEATERS

Examine connections to electric water heaters. Ensure that there is a service disconnect adjacent to the unit.

HEATING SYSTEM

Ensure that the heating system has an emergency shutoff switch. Test the switch to ensure that it actually shuts the system down.

For forced air systems, including central air conditioning systems, look for a bond between the metallic ductwork and ground. If the ducts should somehow become energized, the ground connection can save someone’s life. If no ground is observed, recommend one be installed.

CENTRAL AIR CONDITIONING SYSTEMS

Ensure that a shutoff switch exists adjacent to any air handlers. Each air handler should have its own shutoff switch.

Ensure that each central air conditioning compressor unit is also equipped with a service disconnect. Carefully remove cover from unit, and if disconnect is fused, ensure that it is properly rated, according to the specification tag located on the housing of the AC unit. Do not be surprised if you observe a hot, hot and ground connection to the unit, with no neutral. This is considered a proper installation, unless 110-120 volts will be taken for a convenience outlet, in which case a neutral will be required. If that case, a slightly different configuration will be required.

SUB PANELS AND ISOLATED (OR FLOATING) NEUTRALS

In sub panel installations, isolated neutrals are a requirement. What this means is that the neutral conductor, which tracks back to the neutral of the main electrical panel, is bonded to a bus bar in the sub panel which is electrically isolated from the sub panel casing. The grounding conductor, which tracks back to the main electrical panel, is bonded to the ground bus bar ad the sub panel casing. Branch conductors are connected normally, but are segregated, with only neutrals going to the neutral bus bar, and only ground conductors connected to the ground bar. The came rules apply, with each neutral conductor having its own terminal lug on the neutral bus bar.

The only place in which the neutral and ground conductors can be commoned is at the main panel.

APARTMENTS AND CONDOMINIUMS

Many apartments and condominiums have electric maters installed far away from the unit, or from the main electrical panel. In fact, if the main electrical panel is on the interior of the dwelling, and is further that 8’ from the meter, an electrical disconnect must be installed. An exception to this rule may apply if a conduit is provided, which is buried or encased in concrete. This disconnect is commonly installed below or adjacent to the meter, itself. Note the rating of this breaker, as it will indicate the service rating to the unit. This configuration means that the disconnect functions as the man panel, and the panel in the dwelling, itself, is actually a sub panel. As such, an isolated neutral is required.

ATTICS

When entering an attic pay particular attention to the routing of electrical cables.  No cable should be mounted within 4’ of an attic scuttle or pull-down stair opening. If one is, it must be protected against mechanical damage. Examine all wiring. Ensure that junction boxes are properly covered, and that any switches or receptacles have faceplates. Ensure that all cables are properly secured. Pay close attention to wired in this space. Extreme temperatures in summer may fatigue a cable’s sheathing. UV rays entering the attic from windows or vents can also have an affect on any cable which is continually exposed to the sun’s light.

Extension cords should not be used to connect garage door openers, nor should common household extension cords be staples in place, nor run under carpeting.

Single-pole switches should be mounted so that “up” designates the “on” position.

If you notice sparking when you operate a switch, it may be defective.