Direct Buried THHN/Terminations

[brittle]

I found three open underground terminations while working this past weekend. I explained to the customer this was not to code and also very dangerous. This type of termination could lead to stray voltage and electrocution to employees or customers. My customer has asked for the specific code violation but the only reference I can locate is in reference to approved underground termination in section 300 of UF and USE cables and approved termination devices. I was hoping to find something more specific to what I found vs. what is approved. Example - "all underground wet location terminations must be made in approved junction boxes" etc. but cannot locate. This is going to project managers so it needs to be clear and understandable to non-electrician types. Anyone know of another reference to make my point?

 

[infinity]

I would start with 310.10(F). Also THHN is not permitted in wet locations including inside of a raceway.

 

[Dennis Alwon]

You also have burial depth to deal with. THHN even if it is dual rated thwn cannot be terminated underground. It is not a direct brial cable.

 

[TimK]

Not what you want to hear?

Not what you want to hear?

I found three open underground terminations while working this past weekend. I explained to the customer this was not to code and also very dangerous. This type of termination could lead to stray voltage and electrocution to employees or customers. My customer has asked for the specific code violation but the only reference I can locate is in reference to approved underground termination in section 300 of UF and USE cables and approved termination devices. I was hoping to find something more specific to what I found vs. what is approved. Example - "all underground wet location terminations must be made in approved junction boxes" etc. but cannot locate. This is going to project managers so it needs to be clear and understandable to non-electrician types. Anyone know of another reference to make my point?

View attachment 7552

You are looking in the right area, 300.5(E), to 110.14(B) and 300.15(I) and (G). Now with that being said, first check and see if the THHN is dual rated, chances are yes but check anyway, NEEDs to have THWN on it, second the THHN/THHW/THWN is not approved for direct bury, must be in a conduit, conduit body, box, gutter whatever, USE/UF direct bury. Third i do not believe the tan wire nuts in the picture and electrical tape is an approved underground splice connection.:happysad: