mshields
Senior Member
- Location
- Boston, MA
Ordinarily we specify concrete encased PVC for incoming services to a building.
I've got a client who would like to utilize directional boring to install a 1600A, 480Y/277V service from the service pad mounted transformer to the new service switchboard. I had no knowledge of this technology previously but have learned that this equipment bores a whole large enough for 4 - 4 inch conduits.
I told him I wanted 6 (to provide 2 spare) so he'll bore those two in a second hole immediately adjacent to the first. I think they need to be something like 18 inches apart. Once the holes are bored this guy will pull back through the hole 4 Schedule 40 HDPE conduits in the one whole and 2 sched 40 HDPE in the second hole.
The directional boring guy has told me that he does a lot of work for NStar and that this is the technique that they use. I don't have any immediate concern with it. But as I've never done it before and as I know full well the NStar can do what ever it wants and I can'ts, I wanted to take the temperature of this approach with this erudite group.
What do you think? Obviously we need to adhere to the depths in Chapter 3. Other than that, I don't see any code issues. Do you?
Thanks,
Mike
I've got a client who would like to utilize directional boring to install a 1600A, 480Y/277V service from the service pad mounted transformer to the new service switchboard. I had no knowledge of this technology previously but have learned that this equipment bores a whole large enough for 4 - 4 inch conduits.
I told him I wanted 6 (to provide 2 spare) so he'll bore those two in a second hole immediately adjacent to the first. I think they need to be something like 18 inches apart. Once the holes are bored this guy will pull back through the hole 4 Schedule 40 HDPE conduits in the one whole and 2 sched 40 HDPE in the second hole.
The directional boring guy has told me that he does a lot of work for NStar and that this is the technique that they use. I don't have any immediate concern with it. But as I've never done it before and as I know full well the NStar can do what ever it wants and I can'ts, I wanted to take the temperature of this approach with this erudite group.
What do you think? Obviously we need to adhere to the depths in Chapter 3. Other than that, I don't see any code issues. Do you?
Thanks,
Mike