This article is about Hazardous Location Conduit and Cable Sealing Work Procedure of Electrical Power System Systems as per International Codes and standards for Commercial Buildings, Plants and Refinery Projects.
Hazardous Location Conduit and Cable Sealing Work Procedure
- The purpose of this procedure is to check for the detailed requirements that shall be integrated into the hazardous location conduit and cable sealing special work procedure.
- Personnel shall be qualified, trained, and approved for conduit and cable sealing prior to start of activity. NEC 110.3(B)
- Conduit and cable sealing personnel shall hold a valid Job Clearance Card (JCC) issued by ID prior to commencement of pouring conduit sealing fittings and glanding of cables. NEC 110.3(B)
- The pouring and damming crew shall be trained on the specific manufacturer’s instructions to ensure understanding of the mixing volume requirements and depth of pour. NEC 110.3(B)
- All pours of conduit seals and glanding of cables shall be witnessed by PID.
- Should conduit seal pours be deemed suspect by PID, the contractor has the option to remove the fitting and repeat the pour or radiograph the suspect pour at zero and ninety degree positions. Defective pours shall be removed and repeated.
- The sealing compound utilized shall be taken directly from the manufacturer’s original container at the pouring location.
- The sealing compound shall be from the same manufacturer as the conduit seal (i.e. Chico compound is only to be used on Crouse Hinds conduit seals).
- The same pouring team will perform all the damming and pouring activities.
- The location of conduit and cable seal installations shall be per the approved electrical area classification drawings. NEC Art. 505, SAES-J-902, and SAES-P-104.
- Prior to proceeding, the cable shall be completely tested. The fiber dam and sealing compound shall be installed in strict adherence to the manufacturer’s instructions and the manufacturer’s instructions shall be available at the pouring site. NEC 110.3(B).
- The following sequence shall be followed for all conduit seals unless specific manufacturer’s instructions state otherwise.
- Using fiber, make a dam in each conduit hub, leaving a sufficiently sized pour hole, so that fluid sealing compound cannot leak from the sealing chamber. Proceed as follows to pack proper fiber dam.
a) Position the conductors forward so they do not impede the work.
b) Pack fiber into each conduit hub behind the conductors.
c) Position the conductors backward and spread them apart.
d) Pack fiber between and around the conductors in each conduit hub.
e) Pack fiber into each conduit hub in front of the conductors. CAUTION: Remove all fibers from the sealing chamber and conductors. The completed dam and conduit stop shall be level.
f) If the conduit is of a type or size that has a separate work opening, this should be closed by its cover before pouring the seal.” - Compound:
Follow these instructions carefully.
a) Use a clean mixing vessel for every batch.
b) The manufacturer’s specified proportions by volume compound and clean water shall be strictly followed.
C) Do not mix more than the quantity that can be poured in 15 minutes after water is added.
d) Stir immediately and thoroughly.
e) Fill the conduit sealing compound to the level recommended by the manufacturer’s instructions. NEC 110.3B” - Conduit seals shall only be poured at temperatures between 35-85 degrees Fahrenheit. NEC 110.3B
If a batch has started to set, do not attempt to thin it by adding water or by stirring. Discard partially set material and make up fresh batch. After pouring, immediately close the pouring opening. NEC 110.3(B) - This procedure includes the inspection, installation, and pouring of conduit sealing fittings items stated in SAES-J-902 Sec. 6 and cable glandings in SAES-P-104 Sec. 15 .
- All jobsite conduit seals and cable glands shall be uniquely identified with permanent paint to indicate if the compound has been inserted and/or poured.
- All jobsite conduit seals and cable glands shall be uniquely identified with a tracking number and tracked in the contractors database. The database shall contain damming and pouring dates.
International Standard and Codes for Switchgear Room / Substation, Equipment Installation
- METHOD STATEMENT FOR TESTING & COMMISSIONING OF SWITCHGEAR
- Advanced Power and Energy Meters Technical Requirements
- SAES-B-068 – Electrical Area Classification, May 2003
- Manufacturer’s Instruction – Crouse Hinds, Appleton, O Z Gedney etc.
- NFPA 70 – National Electrical Code, NEC 2008
- SAES-P-104 – Wiring Methods and Materials, January 2008
- SAES-J-902 – Electrical System for Instrumentation.