All you need to know about UF-B Wire before making a purchase

1. What is UF-B wire?

UF-B means Underground Feeder and Branch wiring cable. It has an added protection that allows for underground burial with no additional raceway, tray, or conduit. Generally the UF-B cable is used as a feeder and its cost is slightly higher compared to other cables; closest substitutes like the NMB and MC cables.

UF-B cables come as a two or three conductor cable which consists of the phase conductors and ground wire.

The type of conductors are THHN/THWN-2 which are insulated so that they are able to handle or pick up with high heat and excessive moisture. Below is a breakdown of what the insulation infers.

The conductors are in either solid or compressed stranded copper. The phase conductors are usually color coded for identification.

Each conductor is jacketed with dry and moisture-resistant polyvinyl chloride (PVC) and lead-free jacket. The PVC armor is color code in gray color. The lead-free, water and moisture-resistant PVC jacket also protects the conductors against, abrasion, wear, tear, ozone, UV rays and fungus.

2. General Applications of all UF-B Wires

The common use of this underground Feeder cable (UF-B) is to carry power from a distribution point of a building to an outside post which may be an outdoor lamp or pump. You can also use this UF-B copper underground feeder cable to supply power in an agricultural or a residential building.

3. Why is it a good pick for underground installation?

You can use UFB wire if you want an underground distribution system because it is designed in a way that it can be buried directly in the earth hence it is suitable for underground distribution.

Therefore, UF-B is recommended for underground application since it is able to withstand the punishing environment under the ground. The UFB cable cannot be affected by acids, ground water, any corrosive fumes, and alkalis among other harmful chemicals which they may get in contact with in the ground.

4. Outstanding features of UF-B Cables

This cable withstands temperatures of up to 90°c whereas it can handle power of up to 600 volts and 20 amps current.

Specifications

• UFB cable is UL listed for direct burial
• Minimum length you can purchase is 100 foot
• Weighs 9.51 pounds
• Its conductor gauge is 12 AWG
• UFB cable voltage is rated 600
• Maximum Amperage is 20
• Has 2 or more conductors
• Gray in color on its jacket
• Recommended for outdoor and indoor environments
• Conductor material is copper
• You can use it in both wet and dry areas

Approvals and Certifications of UF-B Cables

• UL Standard 83
• ASTM –B3 and B-8
• Federal Specification A-A-59544
• RoHS/REACH
• UL Standard 493
• National Electrical Code , NFPA 70, 2011 Edition

5. Construction of UF-B Cables

Conductors

The cable is made of annealed copper conductors which will provide you with best conductivity and stability for a longer time.

Jacketing

Each conductors are insulated with a lead-free, dryness and moisture resistant polyvinyl chloride (PVC) jacket, they are then jacketed by a gray PVC armor that protects the conductors against fungus and UV rays. Therefore, UF-B cable is able to serve you for a long time because its durability due to the insulation.

Stranding

UF-B copper conductors are designed in either compressed stranding or solid copper form. Stranding involves twisting small copper wires against each other, same thing as with ropes. It improves efficiency of transmission and flex life of the cable. You may use the stranded design in areas where flexibility is much needed and the solid design is effective in outdoor corrosive environments because less surface area is exposed here.

6. Types of UF-B cables

There are various types of these cables. What creates a difference between the cables is the sizes (because they are of different sizes), the number of conductors and the conditions in terms of temperature where individual type of UF-B cable is able to work. They also differ in prices so you may get the cables according to the cash you are willing to pay.

There are very many types of UF-B cables available for sale of Nassau Electrical. They are all developed based on the same basic principal described above. You may skim through our website and see all the options. On this post, I will review of two of the most widely used UF-B Cables