Cable instead of conduit for trench?

[NetNathan]

I am installing wiring in a trench from the distribution panel to the equipment. It is all inside the building.
The feeds are:
(1) 400 A / 3 ph / 400 V
(1) 250 A / 3 ph / 400 V
(1) 100 A / 3 ph / 400 V
The trench is 12" wide and 8" deep with a cover on top.

Is there an easier way of running the wiring in the trench without using conduit? I assume I cannot just put THHN in the trench?
Is there trench rated cable or wire?

 

[jusme123]

...hire a qualified electrician

 

[NetNathan]

How about a qualified electrician answer my question?

 

[NetNathan]

The problem comes from if I use conduit, The 90 degrees sweep coming up will mean my trench has to be deeper to keep the bent section of the 90 in the trench.
I don't really want to have to do that, that is why I was trying to use cable.

The distribution panel is wallmount with the trench coming under it.
Customer want it done this way because the is a crane rail that prevents me from coming out the top of the Distribution Panel and running it in the ceiling.
I can change the size of the trench.

 

[charlie b]

How about a qualified electrician answer my question?

We have any number of qualified electricians who know the answer to your question. But forum rules do not allow us to provide assistance in the design, installation, testing, maintenance, or operation of electrical systems to a person who is not an electrician. The concern is that you might get an answer to the one question you did ask, but not get answers to the dozens of other questions you were unaware that you needed to ask. The owner of this forum does not wish to put you or your fellow employees at risk as a result of your receiving too little information to do the work safely.

With that being said, I am closing this thread.