A 100-A sub-panel would be fed from a 100-A breaker.
AWG # 3/0 copper.
Yes, the wire size has to be increased. The existing 100 amp service will now probably have a #3 conductor with an insulation factor of 75 or 90 degrees C which is rated for 100 and 105 amps respectively. Increasing to a 150 amp service will use a #1/0 wire size. If you are thinking of an upgrade, skip the 150 amp service and go to a 200 amp panel. New homes are installing 200 amp 42 circuit panels. The extra cost is only reflected in the materials as the labour costs will be the same regardless whether a 150 amp or a 200 amp panel is installed. The wire size for a 200 amp panel is #3/0. With an insulation factor of 75 or 90 degrees C the rating is 200 or 210 amps respectively.
A #3 copper conductor with an insulation factor of 90 degrees C is rated at 115 amps. Even though the panel is rated at a higher amperage it is the main breaker that governs the wire size.
i just left lowes an they told me to run 100 amp to my building i would need wire size 2-2-2-4 alumninum and run it in conduit the lowes around here does not sell copper wire that size
#2 Copper with TW insulation is required for 100 amp loads #3 Copper with R90 insulation is rated at 105 amps.
A 100-A sub-panel would be fed from a 100-A breaker.
Yes, they are the same size wire.
#2 aluminum for 100 amp
AWG # 3/0 copper.
If what you state in this question is accurate this is an illegal installation. A 100 amp service can not have any equipment connected to it less that that of the service size. The 60 amp main panel must be a 100 amp panel to be a legal installation.
In the service distribution panel there are termination points at the top of the panel. Two of the utilities "hot" conductors terminate on the main breaker. The neutral utility termination point is on a terminal block usually off to the side near the main hot terminations. It is in this neutral termination block where the system ground connects from the ground rods to the distribution panel. For a 100 amp panel the wire size will be a #6 bare copper conductor.
20Sqmm
Yes, but at every reduction in wire size there has to be a breaker sized to the smaller wire size. The wire size for 100 amp panels is recommended at #3 copper conductor. From the 200 amp feeder panel you will require a 100 amp two pole breaker for each of the two 100 amp services. Keep in mind that if you run the 100 amp services close to maximum this will take away the capacity of the 200 amp service for other branch circuits coming off of it. Also keep in mind that if the panels are located, not in the same building as the 200 amp service that the 100 amp panels will be treated as separate services and will have to be constructed like a 100 amp service. This includes ground rods. Also the bonding screw will have to be removed that connects the neutral buss to the panel enclosure.
The wire size in a meter stack is governed by the size of the first over current device.
It is not in parallel. You put a breaker in existing panel and use that to feed the subpanel. The Amperage of this subfeed breaker should match the rating of the new panel. For example a 100A breaker might be typical. Remember that ground and neutral are only "bonded" at the main panel. Usually a subpanel has a means to separate the neutral and ground in a subpanel. Be careful since everything about doing this is dangerous.Another AnswerYes, you can have two breaker panels in parallel. If you had a 100 amp panel on a 200 amp service (or increase the size of the service, check with your power company on the size of your service, you could add a second 100 amp panel in parallel with the first. You can have up to 6 disconnects per service, but they must be located adjacent to each other or in the same enclosure. So either install the second panel beside the first or a 100 amp disconnect beside the first panel and feed out of the disconnect to the new panel located where you need it.
Look to see if the 30 amp panel is fed with a two wire or a three wire. If it is a two wire then you are out of luck. If the panel is fed with a three wire then the panel should have the neutral terminated in the panel. It is this neutral that you need for 120 volt connections. You didn't state how many panel slots there are in the panel. If you are able install a 15 amp breaker into the panel and connect the wires going to the load. The black wire will go to the breaker and the white wire will go to the neutral bar in the panel.