Mike Dolt Enterprises
Mike Dolt Enterprises
User: DM2-Inc, Location: Houston, Texas
Asked on: Saturday, March 19, 2011 at 2:51 pm EDT
Answered on: Tuesday, May 14, 2024 at 3:01 am EDT
Question: I'm trying to determine the type of cable to spec for an electrician who is doing the installation for us. The installation is for a floating roof tank, fire detection system. The cable/cord will have one end attached to a platform at the top of the tank which is fixed. The other end will attach to the roof of the tank which floats on the liquid inside of the tank. This isn't the "Heat Detection" cable but rather a cable that connects the "Heat Detection" cable to the fire alarm IDC.The area is considered hazardous. This cord I'm talking about will have to have labels every 25' with "Intrinsically Safe Circuit" printed on the label because I don't think I can get a cable rated as a "Cord", which is light blue in color (ref NFPA 70, 504.80(C).I hope I've explained this correctly, but what I'm looking for is the "Type" of cable to use for this "Cord".Everyone's help is appreciated.
Type of Cable
Based on the hazardous area requirement, the cable you need is an
Intrinsically Safe (IS) Cable.
Construction
Copper conductors
Stranded or solid
Insulation
Heat-resistant and flame-retardant material, such as XLPE or FEP
Shielding
Optional, but recommended for added protection against electromagnetic interference (EMI)
Jacket
Durable and flame-retardant material, such as PVC or polyurethane
Labels
Every 25 feet, the cable must be labeled with "Intrinsically Safe Circuit."
Additional Considerations
Certification
Ensure the cable is certified by a recognized testing laboratory, such as UL or CSA, for use in hazardous areas.
Hazardous Area Classification
Determine the specific hazardous area classification (e.g., Class I, Division 1, Group D) where the cable will be installed.
Bend Radius
Consider the flexibility of the cable and the bend radius required for the application.
Temperature Rating
Ensure the cable is rated for the temperature range it will be exposed to.
Commonly Used IS Cable Types
Belden 8451 Alpha Wire XHHW-2 IS Rockbestos S-630 ITC EPR-IS Pirelli General Dtorque
Note: It is highly recommended to consult with a qualified electrician to ensure proper selection and installation of the cable. Flag for review