In the main panel you'll see the main disconnect for the entire electrical system in the house. The main disconnect is similar to the water and gas main shutoff valves. Sometimes the main disconnect is located outside the house, next to the electrical meter. The main disconnect should be at least 30 inches above the ground and no more than seven feet high for safety. This will enable it to be safely turned off in case of an emergency.
Check the main disconnect for an amperage rating number. It should be written right on the circuit breaker or fuse. Fuse systems have either a pullout use box or a cartridge fuse for a main disconnect. A pullout fuse box is simply a cartridge fuse inside a small box that's pulled out to shut off all the electrical power to the house. A cartridge fuse is a fuse that looks like a miniature stick of dynamite that has metal blades at the top and bottom.
Do not pull out the main disconnect box or touch the cartridge fuse if you can't see their rating number!! Just tell the client that you can't determine the amperage on these disconnects due to the type of system it is. Tell them to have a licensed electrician find out the amps.
After checking the amperage rating of the main disconnect, check the main electrical panel for an amperage rating number. It should be listed on the sticker glued to the panel cover door. If it's not on the door, then the amperage rating should be listed inside the main panel cover. Do not remove any electrical panel covers unless you are a licensed electrician!! Just tell the client that you can't determine the amperage on the main panel due to the lack of a visible data sticker. Tell them to have a licensed electrician find out the amperage for them.
The purpose of checking these amperage ratings is so that you can learn what the maximum amperage is for the house electrical system. The house maximum amperage is the lowest of these three items:
Number 1 is the capacity of the service entrance lines.
Number 2 is the capacity of the main electrical panel.
Number 3 is the capacity of the main panel disconnect switch.
Make sure the system has the proper amperage ratings for safety. For example, if the size of the service entrance lines has a capacity for only 60 amps and the main disconnect capacity is 100 amps; then the main disconnect won't provide the overload protection required for safety. It will be just like you installed a 30 amp fuse on a 15 amp branch circuit line. The wire could become overloaded and start a fire. The same is true if the main electrical panel has a capacity for only 100 amps and the main disconnect capacity is 150 amps. Here again, the main disconnect won't provide the overload protection required for safety.
The National Electric Code recommends that the minimum amperage for a house be 100 amps.
The National Electric Code recommends that the minimum amperage for a house or condo be 100 amps. This is because the older 30 and 60 amp electrical systems can't handle the extra usage more common today with air-conditioners, computers, appliances, etc. A 60 amp electrical service will generally be a nuisance for the homeowner due to blown fuses or tripped circuit breakers with the typical electrical usage.
If you recommend to the client that the electrical system be upgraded from its present amperage capacity; then tell them to get a price quote for installing a 200 amp circuit breaker system in the house. There usually isn't a big price difference between 100 amp and 200 amp electrical installations and the benefits of 200 amps far outweigh the costs. Some of the benefits are:
Central air-conditioning can be installed with 200 amps.
Additions and more branch circuits can be added to the house with 200 amps.
You don't have as many problems with overloaded branch circuits with 200 amp service.
Overall, it's much more convenient to have 200 amp service.
It's extremely important that the electrical system be grounded to a properly working grounding cable attached to the water main line or a grounding rod in the soil. Make sure the client understands the importance of maintaining a properly operating grounding system of the electrical service for safety. Review the plumbing section of this book which details the electrical ground cable attachment near the water meter.
As you go through the interior and exterior of the house check for any loose wiring that needs to be secured or any electrical hazards. Make sure you warn the client and the homeowner of any hazards. Remember, electricity can kill people so be very thorough and careful during the inspection.
In very old houses you might see some Knob and Tube wiring. This can be detected by the existence of white ceramic holders that were used many years ago to hold the electrical lines. All knob and tube wiring should be upgraded with modern electrical wiring by a licensed electrician for safety.
Check for loose switches and outlets that need to be secured. Also, check for any do-it-yourself work in the house. All electrical repairs must be performed by a licensed electrician. All valid permits and building department approvals must be obtained for any work done. As a safety precaution, check to make sure that the outlets and switches in the bathroom are not reachable from the tub or shower. Remember that water and electricity don't mix! Remind your client of this.
You should use an electrical outlet tester to spot check outlets throughout the house for proper wiring and current. These are hand held devices that plug into outlets to check for reversed wiring or improper grounding. Improper wiring can be caused by having the hot and neutral wires reversed in the back of the outlet or a false ground wire. Outlets with these conditions may still provide electrical current but they're an electrical safety hazard and must be repaired by a licensed electrician. Almost all houses you inspect will have some outlets with improper wiring. Just inform the client of the condition so it can be repaired.
Older houses will have the two pronged outlets as opposed to the modern three prong types. The third prong is used for the grounding prong in electrical cord plugs. The purpose of this grounding prong is that most appliances today have an internal ground. For example, let's say a wire came loose inside a washing machine and touched the metal parts. Well, if there was no internal ground or three pronged outlet then the metal casing of this appliance would become electrified. When someone touched the washer, they'd get an electrical shock. The purpose of the internal ground is that it would carry the current through the grounding wire to the third prong. This would then ground the circuit and the fuse should blow or the circuit breaker should trip off. This would prevent the electrical shock caused by touching the metal washing machine.
All two prong outlets should be upgraded to the modern three prong grounded outlets by a licensed electrician.
All two prong outlets should be upgraded to the modern three prong grounded outlets by a licensed electrician. If the homeowner is using plug adaptors to install a three prong appliance into a two prong outlet, then make sure that the pig tail is connected to the screw of the outlet cover plate. The pig tail is the small wire on the plug adaptor. The pig tail is used to help create the same effect as the use of a third grounding prong, if the two prong outlet is installed properly. However, don't use a plug adaptor and leave the pig tail wire hanging loose and don't use an adaptor that doesn't have a pig tail at all. This will defeat the whole purpose of the grounding prong on the appliance and create a false ground that is an electrical safety hazard.