Bad wiring to upgrading; frequently asked questions about electrical issues…
Upgrading old electrical service
The second problem you may encounter is with your insurance company. They are correct to say that this is a 60 amp service. The reason is simply this. The size of your electrical service is determined by the size of the breaker or the service wire, whichever is smaller. Therefore, you have a 60 amp electrical service.
You could easily reduce the risk of fire and improve the overall safety of your electrical system by having a qualified electrical contractor change your main breaker from 100 amps to 60 amps. This will likely bring your system into compliance with Electrical Code specifications. However, your insurance company may still want you to upgrade the size of your service to 100 amps. This can only be accomplished by replacing your 60 amp service wire from the hydro pole to your distribution panel. Also, because the new 100 amp service wire has a bigger wire diameter, you will likely require a bigger service mast and conduit. Unfortunately, none of this work is the responsibility or domain of the public utility service provider. Therefore, you will need to hire a qualified electrical contractor to make these changes to your service if the insurance company requires this upgrade.
Old Knob and Tube wiring
Be sure not to bury the Knob and Tube wiring in insulation. Although there is some debate about this subject, it is generally accepted that this type of wiring works best when the heat build up in the wiring can dissipate unrestricted to the surrounding air. As well, some insurance companies are now reluctant to underwrite new insurance policies on houses with Knob and Tube wiring even though the system may be safe. This comes about with usually with change of ownership on the building.
Older electric fuse panels
When purchasing fuses, look for type “Type P” fuses. They are designed to sense high temperatures around the fuse and blow even though the current draw is low. Appliances with large electric motors like refrigerators and freezers should be fused with “Type D” fuses that permit extra current to flow on a demand start-up without “nuisance” blowing the fuse. This will help limit the number of times your tenants need to replace fuses. Fortunately, for the safety of you and your tenants most modern fuses are designated “Type D and Type P”.
We own an older heritage home and most of the electric receptacles are two prong outlets
However, you can install a ground wire for the receptacle. It may be connected to a nearby water pipe or carried back to the main electric panel. You can also replace the outlet with a GFI receptacle. This is not as good as a fully grounded circuit because in some circumstances you can still get a very brief shock before the GFI interrupts the circuit. With a fully grounded circuit you will not get any shock. Still, a GFI outlet is better protection and often easier to install than a fully grounded circuit. Remember that any appliance (including computer equipment) that comes equipped with three-prong plug relies on the grounded outlet to function safely. Home computers for example, dissipate static charges through the ground wire. The GFI solution will not help in this case because it is not a grounded outlet. Consider consulting with a certified electrician if you are in doubt about the ground requirements for certain appliances. A tradesperson may recommend installing some fully grounded branch circuits if you.
Figure out approximate age of wiring in house
Knob & Tube: rubber casing 1920 – 1950 (also identified by their distinctive porcelain knobs & tubes supporting the branch wiring.)
Two or three wire cables with no ground wire – 1945 to early 1960’s
Cloth Sheathed: two or three wire with an integral ground wire – Early 1960’s to early 1970’s
Cloth sheathed aluminum wire with an integral ground: – 1964 to 1978
Plastic sheathed aluminum cable with an integral ground wire: – 1974 to 1978
Plastic sheathed copper cable with an intragal ground wire: – 1974 to date
Be cautious when opening your electric panel. Remember your dealing with a potential killer. Consider completing this investigation in the company of a qualified electrician. Happy sleuthing!
Higher amperage outlets
These outlets and their branch circuit wiring have a unique configuration because they are designed to handle higher amounts of amperage required to operate electrical equipment that demands more than a “normal” 15-amp outlet can provide. For instance some 20-amp receptacles have a neutral slot set at right angles to the hot slot. Conventional plugs will not fit into these slots. Some outlets have one t-shaped slot that will accept either 15 or 20 amp plugs. Some jurisdictions now require new homes to be equipped with one or two of these 20-amp circuits. Often these circuits are located in kitchens and dining rooms. Another common place to find one of these higher amperage outlets is in a workshop or garage where the previous owner may have installed the outlet(s) and heavier gauge branch circuit wiring to run a welder, compressor or other large demand workshop industrial equipment. Remember that these “unconventional” outlets are rated for larger amp loads and should not be installed on wiring that is designed for 15-amp circuits.
Aluminum wiring was introduced in the 1960’s because it was a less expensive alternative to copper wiring, even though larger wire gauge sizes were required and it was not as good a conductor as copper. Some problems associated with aluminum wiring are that the wire tends to creep out from under the terminal screws, the wire can oxidize reducing conductivity, and the wires can be easily damaged during installation. Several house fires were attributed to this wiring as a result of these deficiencies. Industry then responded to these concerns by designing connectors, receptacles and switches better suited to this wiring. Not all houses were retrofitted with this hardware so you should confirm that your receptacles, switches, connectors and fixtures are labeled CUAL and / or CO/ALR. The latter designation was introduced in the early 1970’s and used tin-plated terminals. This hardware more effectively controlled over-heating problems than the earlier CUAL hardware.
As well, if your home is equipped with aluminum wiring you should check for aluminum compatible equipment at the main panel. First, you or your electrician can check that the panel and circuit breakers have the aluminum designations (CUAL). There are even specially designed aluminum wire twist-on connectors, which continue to create controversy concerning their safety. These wire nuts are not easily identified, so again, consult your electrician. In the main panel all larger stranded wires in contact with terminals should be coated with an anti-oxidant paste to prevent aluminum oxide from forming where the aluminum comes in contact with the air.
If you have aluminum wiring here are a few tips. Watch for signs of overheating especially at receptacles that are used for large demand appliances like clothes dryers, hair dryers and portable heaters. Have your local electrician do a detailed inspection, including a review of circuit wiring for loose wires at terminals. In the big picture, aluminum wiring can be safe if it has compatible receptacles, switches and fixtures and the wiring is maintained and serviced regularly.
Bad wiring in electrical panel
The circuit ground wires should be idle and should be used to carry current only in emergencies. When you connect these ground wires to the neutral bus bar, the ground wire is more likely to carry everyday household electricity instead of emergency power from situations like short circuits. So, its’ ability to handle these emergencies is diminished. As well, since the ground wire is a bare wire people don’t expect it to be carrying electricity. So there is a potential for shock. The bare copper ground wires in branch circuits are connected to outlet boxes and equipment cases. If these ground wires are bonded with the neutral wires at the panel, the outlet boxes and equipment cases can become energized, which can also lead to shocks.
The simple solution is to shut off the main power to the building and then remove the ground wires from the neutral bus bar. Relocate them on the panel ground terminal where they belong. Whenever these types of problems are detected in a panel, it is a good idea to get a qualified electrician involved in the repairs. Often when you see ground wires that are located on the neutral bus bar, other problems also exist. So while the electrician is present, ask the person to look for other potential wiring problems like over-sized breakers, circuit wires crossing over the main bus bars, double taps and bonding issues.
“Load miser” and 70-amp service at full capacity
Another indication of your electrical capacity is the fact that your home is equipped with a “load miser”. Often, when a house lacks sufficient 240 volt circuits in the main panel for the number of major appliances in the house, a load miser is installed. This usually indicates that the electrical capacity in the house is marginal for the number of major appliances in use. For example, commonly, a clothes dryer and an electric hot water heater are served by their own dedicated 240 volt circuits. In your home it is likely that they share the same circuit with a single 30 amp breaker and a single 10 gauge wire.
The load miser is a switching devise that supplies current to one of these two appliances at a time since there isn’t enough current carrying capacity in the 10 gauge wire to operate both appliances simultaneously. Therefore, the load miser gives one of the appliances priority. The load miser cuts off power to the non-preferred appliance when the current flowing through the miser reaches 80% of the upstream fuse or breaker rating.
For instance, in the example of the hot water tank and clothes dryer, the hot water heater may be drawing power most of the time. But, when the clothes dryer is in use, the load miser will cut electrical flow to the hot water tank and supply only to the clothes dryer.
It is very unlikely that you will have enough electrical capacity to heat a hot tub given that there are apparently not enough circuits or capacity for your existing appliances. You may be faced with an upgrade to your electrical service. This will probably entail installation of a new 100 amp service wire and main panel. However, before you begin this project, I recommend that you consult with a certified electrician who will be able to assess your electrical loads and corresponding service size.
Buzzing sound from electrical panel
The least likely source may be a small low voltage transformer attached to or near your main panel. The most common of these would be a doorbell transformer. Look for a small metal box with light gauge wiring running from and to it. These transformers often hum, but this is not the most probable source of the annoyance.
A more likely source of the problem is a loose breaker. Often, the contact point between a main or circuit breaker and one of the power supply buss bars will loosen and a small gap will occur between the two contact points. The gap or loose contact point will hum when electricity flows across the contact points. There is a possible simple cure for the problem. Open the panel door when you hear the humming. Do not remove the main panel cover. You will be looking at the main and circuit breakers. With your finger on a breaker, press each breaker in turn pushing it toward the back of the panel. If the humming stops when you press a particular breaker, you have found the loose contact point.
However, if the humming continues after you release pressure on the breaker, the contact points on the breaker or the harness that holds the breaker is worn to the extent that new a breaker, breaker harness or buss bar(s) may be required. If the humming cannot be eliminated by simply pressing on the breaker, I suggest that you contact a qualified electrical contractor for any further investigation because loose contact points and loose wires attached to breakers can cause short circuits and electrical fires.