![]() ![]() I ended up getting 2 and will be replacing my 20 year old Crouse-Hinds main panel too. I was just about to buy an 8 slot panel with lugs and a 100A main and realized I could pay less for a really nice panel that includes the 200A main and three 20A and two 2-pole 30A breakers. Once you move to THHN you'd pay so much more per foot that it's more a "I really don't want a splice box on the side of the house" thing than the economical decision.įYI, the Square D HOM3060M200PQCVP is $99 right now. The wire size for 100 amp service is 4 AWG copper wire or 2 AWG aluminum wire. ![]() The cost savings vs other wire types and not needing conduit should offset the need for exterior splice box since that type of wire can't enter the structure (should be fine to terminate in a shed panel, just the house side needs a box).įor a bit of a step up in price you can get mobile home service wire which can enter the structure but I'm fairly sure also requires conduit to bury and possibly isn't rated for burial. Once there, click on their link to free access to the 2017 NEC ® edition of NFPA 70.You can do direct bury 2-2-2-4 URD which will cover you for 155A and be inexpensive. ![]() See the actual NEC ® text at NFPA.ORG for the complete code section. A 100 amp subpanel installation requires 4 AWG copper wire or an equivalent of 2 AWG aluminum wires. The same change occurred in 250.66(B & C) which applies to concrete encased electrodes and ground rings.īelow is a preview of Article 250. This provides a safe path for electricity to flow in the event of a fault, preventing equipment damage or electrical shock. At 24' you could use direct bury cable but putting it in conduit is the right way to do it. Technically, you can cram all that in a 1' conduit, but go with a min of 1-1/2'. Aluminum has a higher resistance than copper, so it needs to be one size larger than copper to carry the same amperage. The NEC recommends 3 voltage drop for either the feeder or the branch circuit and 5 total for both. Running 2 - 100 amp sub-panels you should run 3 THHN wire to each panel with a 100 amp breaker to feed each one. ![]() The National Electrical Code (NEC) specifies that a ground wire of at least 8-gauge should be used for a 100-amp sub panel. Assuming a 100A feeder breaker, use 8 copper. For a 100 amp service using aluminum wiring, the recommended size is 2 AWG aluminum wire. 20 feet is a short run and voltage drop is not a problem in that short of a distance. The above principle was an example of the code change to 250.66(A). When installing a 100-amp sub panel, the size of the ground wire is a crucial factor to consider. If the GEC continues from the rod to another electrode of a different type that requires a larger GEC, then the GEC from the service to the first rod will be under sized for the furthest grounding electrode. It would not be code compliant to run a 6 AWG copper GEC from the service to a ground rod, and then run a GEC bond jumper from the rod to another grounding electrode that required a larger GEC such as a concrete encased electrode.Ĭonsider a ground rod for example If the GEC starts at the service and goes to a ground rod or group of ground rods and stops there, the GEC is never required to be larger than 6 AWG copper or 4 AWG aluminum. Building steel and metal underground water piping that qualifies as a grounding electrode may require a larger GEC since the GEC to these electrodes is sized based on the size of the service entrance conductors and Table 250.66. The minimum size GEC permitted to connect a concrete encased electrode is 4 AWG copper. The minimum ground wire size for 100 amp service is 8 AWG copper or 6 AWG aluminum wire. For the 100-amp service, the ground wire size should be 4 AWG. While looking for the ground wire for 100 amp service, it can be as thin as 10 AWG or as thick as 2/0 AWG. Today, we will talk about the ground wire of 100 amp service. The previous code language seemed to be pretty clear before but for some reason, many people were still confused by the wording.Ī grounding electrode conductor (GEC) from an electrical service to a ground rod, pipe or plate type electrode is never required to be larger than 6 AWG copper or 4 AWG aluminum unless the GEC continues on from the rod, pipe or plate to connect another electrode that may require a larger GEC such as a concrete encased electrode, building steel or metal underground water pipe that qualifies as a grounding electrode. The AWG for ground wire can be similar to the hot and neutral wires or slightly higher. Code Change Summary: A revision was made to clarify the proper way to size certain grounding electrode conductors (GEC’s). ![]()
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |