SITE MAP

Below Ground

  1. What is FRE®?
  2. What US and Canadian standards apply to FRE®  Below Ground products?
  3. What is NEMA TC-14?
  4. What is the difference between the UL 1684 / CSA C22.2 No. 211.3 standard and the NEMA TC-14 standard?
  5. Can we comply with both UL 1684 / CSA C22.2 No. 211.3 and NEMA TC-14 at the same time?
  6. What are the differences between the Below Ground Encased Burial (EB) and Direct Burial (DB) products?
  7. How far should the spigot (male) end be inserted into the bell (female) end to make a good connection?
  8. Is the TriSeal™joint watertight?
  9. Will FRE®  Below Ground conduit permit a cable to fuse to the conduit wall due to fault currents?
  10. Are all FRE® Below Ground products available in 10 foot lengths?
  11. Can FRE® Below Ground conduit be bent in the field?
  12. Is Thin Wall (TW) conduit acceptable for a Direct Burial (DB) application?
  13. Are there any operations needed to be performed prior to making an adhesive joint between the bell and spigot?
  14. Should you remove the TriSeal™ when using an adhesive for assembling the conduit?
  15. Can you install an expansion joint in a Direct Burial (DB) or Encased Burial (EB) application?
  16. What should you use to make joints go together when you try to mate a spigot (male) end and a bell (female) end and it is too tight to fit?
  17. What is the pullout strength of FRE® Below Ground conduit with the TriSeal™?
  18. What is the pullout strength of adhesively bonded FRE® Below Ground conduit?
  19. Should you use a radius bell end fitting when you pull cable?
  20. Can you use FRE®  Below Ground products in a Class 1 Division 2 area?
  21. What is the intended use of an FRE® sleeve?
  22. When you order a Thin Wall (TW) conduit, do you get Thin Wall fittings and accessories?
  23. What is the temperature rating for the FRE®  Below Ground products?
  24. Can other manufacturers produce FRE® products?
  25. Is FRE® recognized by the National Electrical Code (NEC®) and the Canadian Electrical Code (CEC®) as an approved conduit?
  26. Are all available ID and IPS Heavy Wall (HW) trade sizes UL Listed and CSA Certified?
  27. How does FRE®’s coefficient of thermal expansion compare to that of PVC?
  28. How does the flexural strength of the FRE® Below Ground product compare with that of PVC?

1. What is FRE®?
Owned by FRE Composites, FRE® is a registered Trademark in Canada, the United States and other countries for Reinforced Thermosetting Resin Conduit (RTRC) and Fittings.

2. What US and Canadian standards apply to FRE®  Below Ground products?
Underwriters Laboratories’ and the Canadian Standards Association’s binationally harmonized Standard for Reinforced Thermosetting Resin Conduit (RTRC) and Fittings, UL 1684 / CSA C22.2 No. 211.3, provides the requirements for both Encased Burial (EB) and Direct Burial (DB) Below Ground products.

3. What is NEMA TC-14?
NEMA TC-14 is an industry standard published by the National Electrical Manufacturers Association (NEMA) as part of the IPS 14 Technical Sub-Committee (RTRC).

4. What is the difference between the UL 1684 / CSA C22.2 No. 211.3 standard and the NEMA TC-14 standard?
None.   On October 18th, 2002 NEMA adopted the latest version of the UL 1684 / CSA C22.2 No. 211.3 standard as its own industry standard.

5. Can we comply with both UL 1684 / CSA C22.2 No. 211.3 and NEMA TC-14 at the same time?
Yes, since  the standards are the same.  However, this could change from time to time due to new developments.  It is recommended that you consult our literature for the latest information pertaining to these standards.

6. What are the differences between the Below Ground Encased Burial (EB) and Direct Burial (DB) products?
The only difference is the thinner wall thickness for EB products compared to DB products, which affects certain mechanical properties such as compression.  However, all other product characteristics are identical.

7. How far should the spigot (male) end be inserted into the bell (female) end to make a good connection?
For conduit employing the TriSeal™joining system: 5” (127mm). For conduit employing an inside tapered bell without TriSeal™: 4” (102mm).

8. Is the TriSeal™joint watertight?
Yes.  Our proprietary design, one-piece molded urethane TriSeal™ensures, when installed per manufacturer’s instructions, a watertight joint as defined by the National Electrical Code (NEC) and Canadian Electrical Code (CEC).

9. Will FRE®  Below Ground conduit permit a cable to fuse to the conduit wall due to fault currents?
No.  Since RTRC is a Rigid Nonmetallic Conduit (RNC), it is impossible for a cable to fuse to the conduit due to fault currents.  Additionally, epoxy resins can sustain high temperature exposures and, unlike PVC, will not melt under fault conditions.

10. Are all FRE® Below Ground products available in 10 foot lengths?
The standard length for all our 2” (51 mm) and larger trade sizes in both IPS and ID dimensions is 19.68 feet (6 meters).  However, to accommodate specific project requirements, all such products are also available in 9.84 foot (3 meter) lengths.
11. Can FRE® Below Ground conduit be bent in the field?
In the U.S. FRE® Below Ground conduit can be bent in the field for larger radius elbows using standard RNC bending equipment and carefully following our manufacturer’s instructions, in accordance with 352.24 of the National Electrical Code (NEC).  This installation advantage is made possible because of our 68 ± 3% glass to resin content.  RTRC products with a higher glass content will severely restrict this capability. However, in Canada, rule 12-1208 of the Canadian Electrical Code (CEC) prohibits all types of RTRC from being field bent.

12. Is Thin Wall (TW) conduit acceptable for a Direct Burial (DB) application?
No.  Thin Wall conduit does not offer sufficient compression strength to withstand typical Direct Burial (DB) loads without the possibility of ovalizing beyond acceptable levels. This could severely impair cable pulling operations.

13. Are there any operations needed to be performed prior to making an adhesive joint between the bell and spigot?
A light sanding of both the inside of the bell and the outside of the spigot is necessary to increase the adherence of the adhesive. (See manufacturer’s adhesive instructions.)

14. Should you remove the TriSeal™ when using an adhesive for assembling the conduit?
It is recommended that the TriSeal™    joint system not be used with adhesive. If too much adhesive is utilized it can cause build-ups inside the conduit during assembly, creating obstructions which could impair cable pulling operations.

15. Can you install an expansion joint in a Direct Burial (DB) or Encased Burial (EB) application?
In normal circumstances, expansion fittings are not needed for Encased Burial (EB) installations since the movement of the conduit will coincide with the expansion and contraction of the concrete.  The only location where an expansion fitting should be utilized is where the concrete itself has an expansion fitting.  In Direct Burial (DB) situations, expansion fittings are not needed because the ground has relatively constant temperatures.  However in cold areas, conduit must be installed below the frost line to prevent damage during freezing and thawing cycles.

16. What should you use to make joints go together when you try to mate a spigot (male) end and a bell (female) end and it is too tight to fit?
The use of a little wire lube or soapy water on the spigot end will ease the drive of the spigot into the bell.

17. What is the pullout strength of FRE® Below Ground conduit with the TriSeal™?
The minimum pullout strength of our TriSeal™   joint design is 500 lbs (227 kg) for all trade sizes.
18. What is the pullout strength of adhesively bonded FRE® Below Ground conduit?
The minimum pullout strength of an adhesively bonded joint is 1500 lbs per inch trade size (e.g. 4” trade size = 4 x 1500lbs = 6000 lbs) or 680 kgs per mm trade size.                    

19. Should you use a radius bell end fitting when you pull cable?
The use of a radius bell end fitting is highly recommended to prevent damage to the cable during pulling operations.

20. Can you use FRE®  Below Ground products in a Class 1 Division 2 area?
In the U.S., FRE® Below Ground products can be used in a Class 1, Division 2 location if they are encased in a minimum of 2” (51 mm) of concrete and provided with not less than 24” (610 mm) of cover, in accordance with 501.10(B) of the National Electrical Code (NEC). However, in Canada, the Canadian Electrical Code does not permit any type of Rigid Nonmetallic Conduit (RNC) to be used in these locations.

21. What is the intended use of an FRE® sleeve?
An FRE® sleeve is intended to allow conduit to pass easily through pillars, concrete abutments, walls, etc. or to repair a damaged conduit section. It is not intended for joining lengths of conduit.

22. When you order a Thin Wall (TW) conduit, do you get Thin Wall fittings and accessories?
No, it is not always possible to reduce fittings to Thin Wall (TW) dimensions.

23. What is the temperature rating for the FRE®  Below Ground products?
Although  Listed  and  Certified  for  a  temperature range of -40°F to 230°F (-40°C to 110°C), FRE® is intended for 90°C installations in accordance with the National Electrical Code (NEC) and the Canadian Electrical Code (CEC).  However, epoxies are known to perform well in high temperatures (up to 275°F or 135°C).

24. Can other manufacturers produce FRE® products?
No.  FRE®  is a registered trademark owned by FRE Composites and therefore no other manufacturer can make FRE®  products.

25. Is FRE® recognized by the National Electrical Code (NEC®) and the Canadian Electrical Code (CEC®) as an approved conduit?
Yes, FRE® is a Rigid Nonmetallic Conduit (RNC) that is covered by Article 352 of the NEC and as a Rigid RTRC Conduit that is covered by Rules 12-1200 – 12-1220 of the CEC.

26. Are all available ID and IPS Heavy Wall (HW) trade sizes UL Listed and CSA Certified?
No, in accordance with UL 1684 / CSA C22.2 No. 211.3, only  4” (102mm) Heavy Wall (HW) conduit and fittings are currently eligible for Listing and Certification in both IPS and ID trade sizes.

27. How does FRE®’s coefficient of thermal expansion compare to that of PVC?
FRE®’s coefficient of thermal expansion and contraction is 50% lower than that of PVC.

28. How does the flexural strength of the FRE® Below Ground product compare with that of PVC?
FRE®  Below Ground products offer twice the strength to weight ratio of PVC. The higher flexural strength allows FRE® to be used at the maximum spacing distance between supports permitted by the National Electrical Code (NEC) and the Canadian Electrical Code (CEC).