Step 1: Pick Load. There are five different categories of load ratings that are used for most underground enclosures, depending on the type of traffic and how much traffic the enclosure will be exposed to.
1) Greenbelt (Light Duty & Tier 5) — For enclosures that will be protected from vehicular traffic, such as in golf courses, parks, and lawns. Injection Molded Plastic is traditionally used for such enclosures, but all NewBasis enclosures will work in greenbelt environments. Minimum test loads for these enclosures are 3,000 pounds for light duty and 7,500 pounds for Tier 5.
2) Non-deliberate vehicular traffic (Tier 8) — For enclosures that get limited vehicular traffic, such as sidewalks. These enclosures have a safety factor for some non-deliberate vehicular traffic use. All NewBasis fiberglass and polymer concrete enclosures work well for this application. These products are tested per ANSI/SCTE 77 Tier 8 protocol. All include polymer concrete covers. Minimum test loads for these enclosures are 12,000 pounds.
NewBasis does not offer Light Duty, Tier 5 or Tier 8 rated enclosures however our entire line of enclosures can be used for these load categories.
3) Incidental or occasional non-deliberate heavy vehicular traffic (Tier 15)— For enclosures that get occasional heavy vehicular traffic, such as non-deliberate traffic areas of parking lots, alleys and sidewalks. All NewBasis fiberglass and polymer concrete enclosures work well for these applications. These products are sometimes referred to as “20k” and are tested per ANSI/SCTE 77 Tier 15 protocol. Minimum test loads for these enclosures are 22,500 pounds.
4) Incidental or occasional non-deliberate heavy vehicular traffic (Tier 22)— For enclosures that get occasional heavy vehicular traffic, such as non-deliberate traffic areas of parking lots, alleys, sidewalks and off the roadway/highway applications. All NewBasis polymer concrete enclosures work well for these applications. These products are tested per ANSI/SCTE 77 Tier 22 protocol. Minimum test loads for these enclosures are 33,750 pounds.
5) Deliberate vehicular traffic or full heavy traffic use (AASHTO materials and loads) — For enclosures directly in roadways and freeways. This application only allows for pre-cast concrete, cast-iron and other recognized building materials. Polymer concrete and fiberglass enclosures are not recognized by AASHTO and NewBasis does not supply products that meet these requirements.
Step 2: Pick material.
Incidental, non-deliberate vehicular traffic and non-deliberate heavy vehicular traffic applications can use either fiberglass or polymer concrete. The choice is usually governed by local standard and tradition. When installed and used as designed there is no performance difference.
Fiberglass – Highest strength to weight ratio. Most sizes can be lifted by hand for setting and installation. Best for field modification; holes can be cut easily with reciprocating saw.
Polymer Concrete – Traditional composite replacement for precast concrete.
Step 3: Pick Shape.
Round or Rectangular. Round boxes are best for looping extra cable; rectangular boxes are more traditional. Round covers can never fall in the box!
Straight sided or Tapered. Tapered boxes nest to reduce shipping costs. Tapered boxes also help resist frost heave. Straight boxes require less digging because they need smaller holes, and they provide easier access to the bottom of the enclosure.
Step 4: Pick Size. On the product page, after you pick enclosure material, you will see a list of available sizes.
NewBasis enclosures range from 11″ X 18″ to 4′ X 8′ X 6′ and can accommodate virtually any application. If you are unsure of what size you need, please contact us at [email protected], and our engineers will help you.