Hand hole sizing

[Rfoster66]

So I was asked by our onsite engineer (civil) what is the minimum size hand hole for a single 1-1/2” conduit (in and out straight through pull) with a 2 hour fire rated wire. Duct bank is 3’ below finished grade. Currently slated for a 2’x2’ quazite style hand hole box.

Are underground boxes same as junction boxes?
1.5”x8=12”?

What is they were to 90 up and out in the hand hole with a U bend?

What size should this box be and what NEC code should we look at. 314.30? Thanks

Note from drawing;
PULL 3#8,1#8G PRYSMAIN LIFELINE 2 HOUR FIRE
RESISTIVE RHW-2 CONDUCTORS THAT MEET
UL2196 TO SOURCE 1 CONNECTION IN FIRE PUMP
CONTROLLER. ROUTE THRU HH-FP-1

Thanks for your help and advice.


Ryan

 

[don_resqcapt19]

That cable likely has a minimum bending radius, and that limit may require an enclosure larger than what is required by the code.

 

[tom baker]

Pulling hand holes or manholes are sized much larger than pullboxes, for example look at the size of your 2x2 compared to code size

With a 2x2 quazite box the duct bank is below the box bottom. Are you using 90s up into the box, with a short nipple on end? Quazite does make box extensions, but with 90s and a nipple you can fill the bottom with peagravel
Or will the 90s put you over 360 of bends?
If straight thru you will need a much deeper handhole

 

[Rfoster66]

Pulling hand holes or manholes are sized much larger than pillboxes, for example look at the size of your 2x2 compared to code size

With a 2x2 quazite box the duct bank is below the box bottom. Are you using 90s up into the box, with a short nipple on end? Quazite does make box extensions, but with 90s and a nipple you can fill the bottom with peagravel
Or will the 90s put you over 360 of bends?
If straight thru you will need a much deeper handhole

Thanks for your reply, I’m not actually doing the work, it was just a question that was asked. I do appreciate the feedback and I will follow up with them on the actual installation.

 

[Rfoster66]

That cable likely has a minimum bending radius, and that limit may require an enclosure larger than what is required by the code.

I hadn’t thought about that, I haven’t pulled this type of cable.

 

[Rfoster66]

Thanks for your reply, I’m not actually doing the work, it was just a question that was asked. I do appreciate the feedback and I will follow up with them on the actual installation.

Do you have a code or calculation for Manhole/Handhole sizing?

 

[Rfoster66]

Pulling hand holes or manholes are sized much larger than pillboxes, for example look at the size of your 2x2 compared to code size

With a 2x2 quazite box the duct bank is below the box bottom. Are you using 90s up into the box, with a short nipple on end? Quazite does make box extensions, but with 90s and a nipple you can fill the bottom with peagravel
Or will the 90s put you over 360 of bends?
If straight thru you will need a much deeper handhole

Do you have a code or calculation for Manhole/Handhole sizing?

 

[tom baker]

Do you have a code or calculation for Manhole/Handhole sizing?

No. Smallest handhole I used was 12x18 concrete with steel lid. I don’t like the quazite boxes as the screw holes get full of dirt. They are lighter than concrete and have a traffic rating. Look in the quazite catalog to see what sizes they have.

 

[mtnelect]

When I see the word "Hand Hole" I am thinking of Public Works language. Like a hand hole for a light standard ?

 

[tom baker]

Do you have a code or calculation for Manhole/Handhole sizing?

I used to go by our WASHDOT specs for sizing. I don’t have a copy but it is available on line. https://wsdot.wa.gov/engineering-st...ations-road-bridge-and-municipal-construction

Also get the standard plan sheets for electrical