bighills
Member
- Location
- Mooresville NC
8" deep trench.... 3/4 rigid from back of house to shed..... Inspector says check 300.5 column 4, should be 12"..... I always thought 6" and column 2.....Is he wrong?
Not always column 2 - read column 48" deep trench.... 3/4 rigid from back of house to shed..... Inspector says check 300.5 column 4, should be 12"..... I always thought 6" and column 2.....Is he wrong?
If yours meets this criteria it's 12". If yours is 240V then it's 18" (interesting?)Column 4 Residential Brach Circuits Rated 120 Volts or Less with GFCI Protection and Maximum Overcurrent Protection of 20 Amperes
8" deep trench.... 3/4 rigid from back of house to shed..... Inspector says check 300.5 column 4, should be 12"..... I always thought 6" and column 2.....Is he wrong?
Have the inspector explain note 4 of table 300.5
"wiring methods types listed in columns 1-3 is used for one of the circuit types in column 4 & 5 the shallowest depth of burial shall be permitted"
So by this even if it is a method used in column 4 it will allow the depth of column 2 which would be 6''
In light of note 4 I understand it as there are 2 possible choices in the "One - and two - family dwelling" row 18" or 12". With this I believe the criteria of column 4 would have to be met entirely before its 12" would count, and if this criterion is not met 18" would apply.
BUT
Maybe I do not understand the table row definitions, is this row only for residential driveways and parking areas? If it is and the two former items do not apply then the top row “All locations not specified below” would be used and the comparison really is 6” vs 12”, that’s bizarre a 240v feeder would be 6” with no Note 4 issue at all (higher voltage shallower ditch lower voltage & GFCI protected deeper ditch??).
The rows are the location of the buried conductors, the columns 1-3 are the type of wiring method, 4&5 are special allowance for circuits that meet these columns requirements, in no case does column 4 or 5 require a deeper depth the 1-3, ...Only work in the column and row that applies to your installation, then add 4 or 5 if it applies, or you will confuse yourself.
Inspector is incorrect.
I am the inspector, and I was wrong. I called the contractor and told him so. I also told him that Mike Holt was a good place to ask his question because this inspector found it while researching his concerns.
I am the inspector, and I was wrong. I called the contractor and told him so. I also told him that Mike Holt was a good place to ask his question because this inspector found it while researching his concerns.
8" deep trench.... 3/4 rigid from back of house to shed..... Inspector says check 300.5 column 4, should be 12"..... I always thought 6" and column 2.....Is he wrong?
We don't have enough information to answer the question. By "3/4 rigid" do you mean rigid metallic or rigid nonmetallic? And, as Augie asked, any drive way or parking areas involved?