With the increasing demand for electrical power today many times a 100 Amp service is not enough. There are still some homes with 60 Amp services. What many People who don't know any better do is install a sub panel and overload the existing service. The truth is you cant just keep adding to an already overloaded service. The service entrance conductors can only handle the amperage they were originally sized to handle, and sometimes less because of deteriorating insulation. This means you cant just keep adding circuits with out upgrading the Service entrance.
Hazards Caused by an Open Neutral Conductor
Another problem is a deteriorating neutral conductor like the picture to the right. You can eventually loose the neutral conductor completely if you let it go too long before replacing the service entrance. This creates a very hazardous condition. If the grounded "neutral" service conductor is open, an objectionable current will flow on metal parts of the electrical system. A dangerous voltage will be present on the metal parts causing an electric shock Hazard. This is especially dangerous in buildings with pools or hot tubs. Also when the grounded (neutral) conductor from the secondary of the transformer is open, the operating voltage for the loads on one line will rise, while the operating voltage for the other line will drop. This causes potential for excessive heat and poses a fire hazard. If the grounded (neutral) service conductor is open, neutral current will flow onto the metal parts of the electrical system. When this occurs in a wood frame construction building, neutral current seeking a return path to the supply will travel into the moist wood framing members. After a few years of this wood will be converted into charcoal, and it can eventually result in a fire. The condition is called pyroforic-carbonization. If you have deteriorating service entrance cable its a good idea to get your service entrance replaced ASAP.
Opportunity For an Upgrade
If you have made the decision to replace your old service why not upgrade to a 200 Amp Service? A 200 Amp service is not a lot more expensive than a hundred amp service. A 200 Amp service gives you room for future expansion and new circuits. Why install a new 100 Amp service only to discover, that you don't have the capacity to add new circuits for that new addition you were planning? Maybe you were planning to ad a hot tub, swimming pool, or central air. Suddenly that 100 Amp Service is not enough. We always recommend going with the 200 Amp Service you will be glad you did.
Whole House Surge Protector Installation
We can also install a whole house surge protector. This can provide some protection to your appliances and electronics in the event of a surge. We Still recommend installing surge receptacles for your expensive electronics for extra protection. Many of the surge protective devices offer replacement for your devices up to a certain amount if the device fails to protect your TV, Stereo, etc...