Ugrade a service

[dt4gotten1]

When installing a 200amp single phase sub panel with a load of 175amps, can the sub panel be tapped off the 200amp single phase main service using a tap rule, or is a bigger service required, and feed it with a 200amp breaker. Also the distance from the main to the sub panel is 50 ft. One more thing, is rigid pipe burial depth still 6 in. under a concrete driveway.

 

[don_resqcapt19]

What is the load on the original service? It is very unlikely you could add an additional 175 amp load to an existing 200 amp service. You will need to do the load calculations to determine how large the new service needs to be.

 

[Bang]

When installing a 200amp single phase sub panel with a load of 175amps, can the sub panel be tapped off the 200amp single phase main service using a tap rule, or is a bigger service required, and feed it with a 200amp breaker. Also the distance from the main to the sub panel is 50 ft. One more thing, is rigid pipe burial depth still 6 in. under a concrete driveway.

If you have a 200A sub, you can only load that to 80%........now you have to go back to what's feeding the sub panel and see if you aren't overloading that breaker as well.

 

[JFletcher]

When installing a 200amp single phase sub panel with a load of 175amps, can the sub panel be tapped off the 200amp single phase main service using a tap rule, or is a bigger service required, and feed it with a 200amp breaker. Also the distance from the main to the sub panel is 50 ft. One more thing, is rigid pipe burial depth still 6 in. under a concrete driveway.

Table 300.5 gives the burial depths. altho it states 6" depth for rigid under 2" of concrete in a trench, it also states 6-24" depending on what is run thru the rigid, single family dwelling, etc.

 

[roger]

One more thing, is rigid pipe burial depth still 6 in. under a concrete driveway.

Since this is a feeder Table 300.5 requires 18" depth for one and two family dwellings. If it were a 120V 20A GFCI protected branch circuit you could get by with 12"

Roger