NEC 314 - Minimum Dimensions

[NYHouse]

All,

I am a little basic when it comes to these things as it is not my field.

I will try to keep the questions short....

1. Does NEC distinguish a difference between handholes / manholes? i.e. contract drawings show handholes and final implemented works were 1.2m x 1.2m manholes.... however base drawing showed 600mm x 600mm handholes with a minimum size caveat.

2. Would sizing calculation for handhole / manhole be different?

Thanks!

 

[Dale001289]

For manholes see Art 110.75; for handholes see 314.29. The two are very different in their construction. As the name implies, manholes are large enough for personnel to enter and may contain a high volume of large underground cables. Manhole construction is quite involved requiring coordination with Civil group i.e. rebar, covers, pulling irons, fixed ladders, and grounding. They may also contain a pump and lighting. Locations have to be carefully planned. (I've seen manholes larger than your master bedroom).
Handholes on the other hand are quite simplistic in nature and can usually be purchased off the shelf through several vendors. They are usually quite small and do not allow for personnel to enter.