Electrical cables in Hazardous Classified Area

[Histor]

Hi,
Is there any standard stating that we need to use Fire resistant cable on Hazardous classified area (Zone 21 and Zone 22)?

Thanks.

 

[waross]

There are cables rated for hazardous locations.
Fire resistance comes under the fire codes rather than the electrical codes.
Fire resistance has to do more with the generation of generation of noxious fumes and the spread of those fumes.
The fire rating may apply to the overall jacket.
We did an addition in a shopping mall where a new feeder had to be run in a return air plenum.
Our original cable of choice was a jacketed, armoured cable.
The inspection department turned the installation down as the cable jacket was not fire rated.
However, the location was dry and the inspector suggested that we strip the jacket from the metal armoured cable in the plenum.
Under the electrical code, any cable with an interlocking metal armour is acceptable for use in return air plenums.

Hazardous location cable:
Some cable constructions have voids between the conductors.
One aspect of hazardous location cable is the addition of fillers so that there are no void spaces where potentially explosive gasses may migrate.


--------------------
Ohm's law
Not just a good idea;
It's the LAW!

 

[PersonalProfile]

AS/NZS 60079.14, that is generally according to IEC 60079.14, states a fire specification in Cl 9.3.9 Resistance to Flame Propagation.

 

[waross]

The markings for wires and cables meeting the flame spread requirements of the National Building Code of Canada
(without additional fire protection) are
(a) FT1* — wires and cables that are suitable for installation in buildings of combustible construction;
(b) FT4† — wires and cables that are suitable for installation in
(i) buildings of non-combustible and combustible construction;
(ii) spaces between a ceiling and floor, or ceiling and roof, that may be used as a plenum in buildings of
combustible construction; and
(c) FT6‡ — wires and cables that are suitable for installation in
(i) buildings of non-combustible and combustible construction; and
(ii) spaces between a ceiling and floor, or ceiling and roof, that may be used as a plenum in buildings of
combustible or non-combustible construction.
*Communication and optical fiber cables marked CMP, CMR, CMG, CM,

--------------------
Ohm's law
Not just a good idea;
It's the LAW!