After passing through the electric meter, the local electrical utility provides electricity to your house through the service panel (also called the distribution center). The panel, which is usually located in a garage, basement or utility room, distributes electricity through individual circuits that run throughout your house.
The service panel in most homes contains circuit breakers, which look like little switches. Older homes may contain fuses, but they serve the same purpose as circuit breakersto stop the flow of electricity when there is a problem.
As a homeowner, you need access to the panel for three tasks:
to shut off power to the whole house if needed (you do this by switching off the large breaker),
to reset a circuit breaker that trips, and
to turn off power to individual circuits when you are doing electrical work somewhere in the house.
You can also add new circuits to the panel box if there is room, but this is usually a job for a licensed electrician.
When inspecting this service panel it is important to ensure safety. After donning the appropriate protective equipment, I then check the dead front for signs of moisture, arching, and signs of current flowing through the cover. Next I prefer to check the perimeter of the box to make sure there are no hazards that might catch fire such as paper or rodent nests. Next I check for any open knockouts and proper wire size for each breaker, proper breakers being used in the panel, proper bonding, and no signs of any other dangerous wiring issues.
The article I read was entitled Electrical Service Panels. This article stresses the importance of safety when inspecting service panels. Areas to watch for when inspecting these components are: insufficient clearance, aluminum branch wiring, sharp-tipped panel box screws or wires damaged by these screws, circuit breakers that are not properly sized, oxidation or corrosion, damage caused by rodents, evidence of electrical failures, evidence of water entry inside the electrical panel, evidence of missing or improper bonding, panel manufactured by Zinsco or Federal Pacific Electric (FPE).
In this course we learned how to perform an electrical inspection. Above is a picture of an electrical panel. From just what can be seen in the picture there are several issues that can be pointed out. One of the biggest is that double tapping occurs several times on the panel.
In the inspection and writing assignment I chose a picture of an electrical panel that had several double tapped breakers. I chose to write about a picture from the gallery of double tapped breakers. This is considered a serious concern and should be fixed immediately.
Cutler Hammer panel has 150 Amp main breaker, 1/0 service entrance conductors and proper grounding. Panel legend is clear and complete. Internal wiring is text book perfect and well organized except a couple of white wires being used as hot wires aren’t re-designated with black tape as they enter the breakers, and many neutrals are doubled clamped in the buss bar.
In the photo, it is clear that there was excessive contaminants inside the electrical panel at the time of the inspection. In this photo in particular, there is over-sprayed paint inside the panel. These could negatively affect the functionality of electrical components and connections. A licensed electrical contractor should evaluate and make the necessary corrections.
Article on electrical service panels stressed the safety concerns with removing a panel cover even noting an episode that electricuted someone. Definitely thinking about getting the magnetic cover handles. The article mentioned the location of the panel, many of the older homes we inspect have a panel in the bedroom closet, I understand it isn’t up to current code, should I make a recommendation that the panel be replaced and relocated?.
I have read https://www.nachi.org/electrical-service-panels.htm - this article makes it clear that safety is very important in removing electrical panel covers. One can die from removing them. It’s important to know the space around you when removing them. All screws should not have sharp tips. There should be proper clearance around the panel.
pictured here is a double bonded screw on the neutral bus bar. It appears as though a neutral wire and a ground wire have been connected to the same terminal. There are plenty of open slots on this bar and there is recommended that each wire have it’s own slot. This 100 amp main service panel’s only other issues were that one yellow “romex” wire was going through a hole not intended for a wire, and the wire was not protected from the sheet metal with clamp or bushing.
Ohms Law states that Current (amps) = potential(votls)/resistance(ohms). Watt’s law states that power(watts) = potential*current. A circuit can feed appliances whose total consumed power is less than the maximum load allowed by the breaker. For example if I had 4 outlets wired onto a single 20 amp 120volt circuit, I would be able to draw no more than 2400 watts combined at any one time without tripping the circuit (theoretically). It is interesting to note that certain electrical devices pull more power than they are rated for when under a heavy physical load, such as an fan blade becoming blocked or a saw cutting through something very hard. Since voltage supplied is constant, this would imply that more current flows through the electrical system when a device is under heavy load accompanied by a decrease in electrical resistance.
In the photo of this 200 amp service electrical panel there was a couple of double lugged wires. Also there was a white wire that should have been taped coming from a breaker. There was also a large jumper wire between the bus bars running over open live hot parts of the panel. Panel should be further evaluated by licensed electrical contractor.
This is a photo of two electrical panels in a home. The panel on the right is a 200 amp main panel and the panel on the left is a 100 amp subpanel. The subpanel is fed from a 100 amp two pole breaker in the main panel.
A ground rod should be a minimum of 8’ long. A minimum #6 ground wire should be connected to it with a listed clamp that is rated for direct burial. The top of the rod should not be left exposed to damage.
This power meter is rated for 200 amps. It is in the proper rectangular housing that is secured to the structure. The service lateral pipe is secured to the housing and does not move with moderate effort. The grounding conductor is protected with a PVC pipe in this installation.
Lock boxes, the new hide a key. We’ve come along way from placing the key under the third rock from the left in the back yard. Now we can let you in to a house from the office in another city and change the combination after you leave.
In the picture we can see 8, 120/240 V electrical meters for 8 town homes. The meters do not have any labeling on them to which unit each one goes. In addition, there was no lightning rods installed in the ground.
