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The electrical service box is the first thing that is important in any electrical job. It might sound like it is a herculean task to install electrical service at your house, but it is a necessary evil, and nothing can go forward without it. If you need to install an electrical service at your house/dwelling, following these general instructions can help make things easier and make the process more pleasing for those looking to get the value for their dollar in electrical work. Generally, the electrical regulations (and they vary from state to state) allow for a service that is as big as you want but not as small. Generally, in this case, the bigger, the safer – if that can be attributed to electricity – in terms of passing inspection! There is always a definitive minimum, which is usually based on the area of your house above the ground. This post was delivered to you by:Residential Electricians San Antonio

In more detail, the service size usually requires 2 considerations:
1) The Load (Calculated) – This is the sum of all your potential loads after general demand factors are applied to the calculation. An average dwelling (about 1076 sq.ft.) has an electric stove and electric dyer, but for gas heating, the demand on the service is around 5000 watts, plus another 7000 watts for the stove (6000) and the dryer (1000). Again this is the load calculation, not the actual number of watts the appliance is rated on. For example, the dryer load is 1000 watts on the system if the dryer is a 4000-watt piece. This is referred to as the basic load of the system. Naturally, adding those watts up (5000+7000) is the 12000-watt load you need. Furthermore, we need to find amperes in our consideration. This is found by dividing the total amount of watts by the service voltage size. In physics, the formula is represented by a = w/v. Surprisingly, although we use 120 volts in the plugs in North America, the service voltage size coming to your panel is 2 wires by 120 each. Thus, the service voltage size total is 240v. Remember, Volts and Watts add up; amps do not! So our minimum amperage required would be 12,000 / 240 = 50 amps. Please remember that this is calculated amperage and not the minimum service size because there is a HUGE DIFFERENCE!
2) The Minimums Service Size – this is the number based on the floor area of your dwelling. Generally – 60 amp – for any dwelling which is LESS THAN 861 sq. ft. The area calculation also includes all the areas of all the floors except the basement / or underground section of the dwelling. The underground/basement area is ignored for the minimum amperes requirement. For any place which is MORE THAN or EQUAL to 861 sq. ft. – you generally need 100 amp service. As mentioned above, this includes all the floors except the basement/underground. San Antonio Residential Electricians
Considerations: Even if your total actual load is way below the service size based on your floor space – i.e., if your calculated load is 50 amps, and your floor space requires 100 amps – you need to install the service size based on your floor space, and not your calculated load amount. This is why you can have a serving size as large as you want but not as small as you’d like. The extra capacity (the difference between 50 and 100) is for future use. Even if you are never going to use it, you might one day sell the dwelling, or your kids will inherit the property, and they might want to do something with it; the extra service size has to be there to allow for this future need. In any case, most jurisdictions will not let you get away with using a service size that is too small for the area/space that you have in your house/dwelling.

60 Amp Service Size – (reminder: can only be used if total floor space is < 861 sq. ft.)- Service switch, fuse, or breaker rating – 60 amps- Hot Wire (Black) – x 2 #6 AWG 90 copper – (other colors can be red or blue)- Neutral (White) - x 1 #6 AWG 90 copper- Service Raceway – 1 inch. Or use #6 TECK Cable.- Meter Base Rating – 100 amps.- Service ground wire – #6 or larger – (this is a bare copper, twisted strand)- Service Panel Size – minimum 16 circuits. This panel can generally supply the usual plugs and central gas/oil heating. 100 Amp Service Size – (reminder: can be used for any property that is less than, equal, or more than 1076 sq.ft.)- Service switch, fuse, or breaker rating – 100 amps- Hot Wire (Black) – x 2 #3 AWG 90 copper – (other colors can be red or blue)- Neutral (White) - x 1 #2 AWG 90 copper- Service Raceway – 11/4 inch. Or use #3 TECK Cable.- Meter Base Rating – 100 amps.- Service ground wire – #6 or larger – (this is a bare copper, twisted strand) Service Panel Size – minimum 24 circuits. This panel can generally supply all the usual plugs, a central electric furnace, a boiler, and a baseboard heater.* Please remember that you need twice as much hot wire as the neutral wire.

Considerations:
At least 2 Spare Circuits are usually required to be left in the panel after you’ve connected all of your circuits. This is for future use.
The Minimum Panel Size – is used only as a guideline for the minimum size as to your needs. A project/house/dwelling might require more circuits or a bigger panel amp rating. Always ensure you have the necessary amount of circuit space in your panel. Neutral AWG Size: – some jurisdictions require one to use the same neutral wire size as the hot (feed) wire. Check with your local authorities. Usually, it’s a good idea to use the same AWG for both the hot and neutral wires.
Fused Switches: – are rarely used in residential settings, but if you plan to install a fused service switch, it must comply with your local authority regulations. Usually, the regulations require that the service conductor ampacity be equal to the calculated service load or around 80% of the switch rating, whichever is greater. For example, if your calculated service load is 120 amps, the service switch must be 200 amps. In this example, the minimum service conductor ampacity is 160 amps (80% of 200), not 120; the load conductors from the switch to the panel must also be the same 160 amps. Neutral – Can, at times, be bare; some jurisdictions will allow a Neutral wire in the service panel pipe to come from the service meter into the service panel. Something else to consider in regards to this is that using a bare wire saves you money and is easier to work with / form when pushing it through PVC piping with tight corners. On the other hand, the insulated wire can be greased easier. When a bare neutral wire is entered into the meter base, switch, or panel, it must be insulated to protect against contact with any live wires. Usually, this is not a problem as the live wires are separated widely enough for any contact with the neutral. Still, in cases where it isn’t, one must insulate the neutral wire (electrical tape) to the same thickness as the insulation of the hot wire. Also, you would insulate from the entrance until the connecting coupling (any exposed sections).