4.. What is the difference between Fire resistant cable and Flame retardant cable?
Fire resistant cable is cable which will continue to operate normally in the presence of prolonged fire for a specified time under defined conditions. Fire resistance cable shall pass test as per IEC 60331.
Flame retardant cable are not rated to continue to operate under fire circumstance but it will resist the propagate of fire into a new area by having behavior in fire under defined conditions which is proven by passing the test as per IEC 60332.
Fire resistant cable is applied to critical circuit which operates on energized to trip or energized to operate and circuit which needs to still operate during fire such as:
Instrument Cable related to signal for activating ESD2, ESD1, abandon platform.
Instrument Cable for fire fighting equipment such as deluge valve solenoid valve.
Cable for safety evacuation and emergency service.
Flame retardant cable is applied to circuit other than mention above. It serve for instrument loop which operates in fail safe mode.
In term of cable construction, it is essential to distinguish the outer sheath colour between flame retardant cable and fire resistant cable. Commonly, fire resistant cable has red outer sheath/jacket while flame retardant may have grey or black outer sheath/jacket.