What is the effect of loose connection in electrical wiring system?

Answer 1

I would like to add two cents to the below answer on loose connections and that is where they can be overlooked. I recently bought some security flood lights from an Ebay seller. I installed one on the corner of my house and when i screwed the bulb in I noticed that it seemed to be loose in the bezel holder. I then examined the inside and found that the bezel is riveted to the insulator with a yellow brass rivet which is very thin. This rivet was loose in the bezel allowing the neutral wire to rock back and forth in the rivet. Now, no need to explain further what this loose connection can do so my advise is to check out fully the rivets that hold the bezel inside the ceramic insulators for loose connections, especially after you insert and tighten the bulb because they are not strong enough to resist the bulb be tight enough to make sure the centre of the bulb or the hot line is tight so that no looseness is there. If you tighten it up to hold most likely the rivets will loosen up after changing out the bulbs over time. If you buy a good floodlight or security light make sure the bezel in the insulator is held together with tight screws instead of rivets. Your home will be worth it.

A loose neutral wire can cause abnormal arcing around its point of connection, usually resulting in the neutral wire becoming unusually hot, burning its insulation off and even causing damage to its surroundings.

A loose neutral wire is also the cause of the majority of electrical fires.

Arcing occurs because the loose wire does not make consistent contact. Sometimes it does make contact and sometimes it doesn't. This can happen due to a variety of factors, such as an outside supply wire swaying in the breeze (if the wire or its connections are damaged), or it can happen inside due to changes in temperature, electrical load, or mechanical disturbance.

Every time the connection is made or broken, an arc forms. Usually this arc is very brief, but it is very hot and so it causes some damage every time. Thus the condition of the connection gets worse over time. At some time that can't be predicted, a large long-lasting arc may occur. This can cause damage to the surroundings, and it can start a fire.

A resistive neutral is closely related to a loose neutral. A resistive neutral occurs when the neutral is connected, but it's not a very good connection. Good connections have extremely low electrical resistance, but a resistive neutral condition has an intermediate resistance -- its resistance is low enough to conduct some electricity, but too high to conduct as well as it's supposed to. This poor connection has several damaging and dangerous effects.

One effect is that a loose or resistive neutral can cause abnormally high and low voltages to occur in the house wiring. For example, a cardinal sign of a resistive neutral is that lights will get brighter than normal at odd times, such as when another circuit is turned on, or when an appliance cycles on. A resistive neutral won't always cause the lights to get abnormally bright, but when it happens, it's a pretty reliable indication that you have a resistive neutral. If you are aware of a situation in which the lights get abnormally bright when other circuits are used, you should call the power company and report that you believe that there is a problem with the neutral connection. They know this can be very dangerous, so they will likely treat it as a high-priority situation.

Another effect of a resistive neutral connection is that the connection becomes hot. As a result, it can overheat its surroundings and even start a fire. Even if it doesn't do either of these right away, it will tend to get worse over time because heat accelerates the ageing of the wire, its insulation, and surrounding materials.

Another very dangerous effect of a loose or resistive neutral is that it can can lead to electrical shocks and even electrocution. The ways this can happen are extremely unpredictable and depend on exactly how your house is wired and the exact condition of the wiring. Here is a real example: if one resident of a certain house was in the shower when another resident used the garbage disposal, the first resident would feel a mild electrical tingle. No one else in the house could feel it. This turned out to be due to neutral wire at the electrical pole that was nearly broken. Only three strands of wire were still connected. Had the remaining strands been allowed to deteriorate further, someone would have been electrocuted. This is just one example of why it's important to get immediate attention for problems with neutral connections.

Answer 2

A loose hot wire is potentially dangerous because it could touch the external enclosure of an appliance. Provided the enclosure is properly earthed this will trip the circuit breaker or fuse, but without proper earthing it is a lethal situation.

Answer 3

The effect, of a loose "hot" conductor at a terminal point, is generated unwanted heat. Any point of a circuit that creates a higher that normal resistance above the rest of the circuit will generate heat. The load current is the same throughout the circuit so the load that flows through the load also flows through the loose joint. If this type of fault is caught soon enough and is corrected by tightening the loose connection, no harm is done.

If not caught in time the symptoms will start with nuisance breaker tripping. If the heating burns off the conductor's insulation then a short circuit fault can occur.

If the loose terminal current is not high enough to trip the breaker and a gradual heat build-up occurs, the temperature can get high enough to create a spontaneous combustion situation to surrounding flammable materials.

This is how electrical fires usually start and why electrical code requirements state that all joint or splices must be made in an approved junction box to contain the spread of flames.

Answer 4

At best intermittent unreliable operation, at worst a fire.