This article is about Innerduct Installation and Identification for Telecom Duct Bank of OSP Telecom Distribution System as per International Codes and standards.
Innerduct Installation and Identification | Telecom Duct Bank
Underground Installation
- Verify and ensure that the proper work permit has been obtained prior commencing the work activity.
- Verify that before entering manholes, tests is made for detection of hazardous gases using the appropriate gas testing equipment as outlined in GI-0002.708, Gas Testing Procedures and SAES-T-603.
- Verify Prior to pre-entry tests, place warning devices, such as traffic cones, men-working signs, flags, and manhole guards, at the manhole. The work area protection setup operation shall be done with promptness to minimize exposure of personnel to traffic. (See SAES-T-603).
- Verify that prior to MH entry, the MH is purged with power blower having a minimum output capacity of 14.1 cubic meters per minute for the period of time shown on the manhole ventilation chart (Table 1) of SAES-T-628 prior to entry. Minimum ventilation time in all situations must not be less than 5 minutes.
- General: Ensure that it is strictly prohibited to take matches, lighters, storage batteries or any items capable of producing a spark or flame (other than approved items or tools) into a manhole, or to use torches, lanterns, lighted cigars, cigarettes, pipes, furnaces, or other types of open flame within 3 meters of an open manhole even though tests indicate the absence of gas. Refer to GI-0002.100, Work Permit Procedures.
- Verify and ensure that hard hats, safety shoes and approved eye protection must be worn by all persons working in the manhole.
Underground Installation – Setting Up Equipment
- General: In all cases, where cable is to be placed in main conduit, verify and ensure that the ducts is thoroughly cleaned before the pull line or cable is placed.
- General: Verify that care is taken to prevent damage to existing cables in manholes when setting up the pulling apparatus or placing tools of any kind. Ensure that workers not stepping on cables or rack hooks when entering or leaving a manhole; always ensure the use of an approved ladder.
- General: Verify that existing conduits is tested in both directions with an appropriate size mandrel prior to placing an underground subduct.
- Verify and insure that the number of sub-ducts to be installed contain:
1. Three sub-ducts, two 1 ½ in (inside diameter) and one (1”) in (inside diameter) or,
2. Four one (1”) in (inside diameter) sub-ducts.
3. Sub-ducts shall have pull rope or pulling tape inside.” - Verify and insure that the sub-duct color which are provided to be placed inside a four inch conduit, shall be different colors.
- Ensure that subduct reels are position so that the subduct is alternately pulled from the top of one reel and the bottom of the next reel to keep the subducts from twisting during installation. (Refer to GTE 624-622-000, para. 5.1, issue 3 April 1992).
- Ensure that Portable two-way radios (minimum of two) or other reliable communications ability is provided in addition to the standard underground placing tools.
- Verify and insure that all sub-ducts are sealed to prevent the entry of dirt, water or debris.
Underground Installation – Placing the Subducts
- Verify and insure before starting underground placing work, all personnel shall know the communication signals that will be used. Personnel shall be stationed at the reel location during pulling activities to maintain proper reel rotation. (Ref. SAES-T-628, para. 4.7)
- Verify that the first 20 feet of subduct is generously lubricated to reduce initial duct friction. Lubricate the sub-duct throughout the pull by applying generous amounts of lubricant (use lubricant recommended by sub-duct manufacturer).
- Verify that subducts pull start slowly until at least two feet of it has entered the duct. From this point, the subducts may be pulled, steadily and continuously, at the rate of 80 to 100 feet per minute. (Ref. SAES-T-628, para. 4.7.5.2)
- Verify and insure when placing sub-duct that the pulling length of underground sub-duct do not exceed 455 meters.
- Ensure that additional personnel is stationed at pull-through manholes to:
a) Help guide subduct into the opposing duct.
b) Alert the pulling personnel in the event of a mishap.
c) Help with lubricating the subduct as it is pulled in.” - Verify that the subduct ends in the manhole upon completion of subduct pulling are plugged and placed on manhole hooks or tied to the racks.
- Ensure that unnecessary bending of the subducts in attaching them to cable hooks or racks is avoided and all subduct bends radii are 380 mm (15 in.) or greater.
- Verify and insure that the sub-duct cutting and splicing shall not be cut or spliced for a minimum of 24 hours after placement to allow for sub-duct shrinkage. Sub-duct splices shall only be made inside the manhole between the cable vertical racks. Threaded, self-tapping type sub-duct couplers shall be used to splice sub-ducts.
Direct Buried Installation
If subduct is to be direct buried, ensure that rigid PVC or heavy-walled polyethylene subduct is provided.
Standards Codes and References for Telecom Ductbank, Innerduct Installation and Identification
1. SAES-T-624,Telecommunication Outside Plant- Fiber Optics.
2. SAES-T-628. Telecommunications – Underground Cable Issue.
3. GI-0002.100, Work Permits
Telecom Closet / Telecom Equipment Room Size And Location.
Telecommunications Infrastructure Design Process.
ANSI/TIA/EIA 568-B Commercial Building Telecommunications Cabling Standard.
Telecommunications Outside Plant Systems Design SAES-T-938 Download.