Electrical Wire Insulation Melting Temperature

During recent years there has been some consolidation.

Electrical wire insulation melting temperature.

The operating temperature of an electrical cable normally refers to the minimum and maximum temperature that the cable can safely operate at for a sustained period of time. The temperature rating of a wire or cable is generally the maximum safe temperature that the wire can carry full load power without the cable insulation melting oxidizing or self igniting. Melt temperature o c 140 140 140 140. If the wires are buried in attic insulation pass over light fixtures or worst of all are arranged in tight bundles they get even hotter than if they re out in the open air.

Melting combinations ithe nfpa notes that electrical fires often occur due to one small incident leading to another which results in a combination of things that cause. Wire temperature limits sets first for safety reasons then to ensure circuit operation. During the historical development of cables numerous types of insulation have been employed. Pvc wire features an extruded insulation that is applied while running it through a die onto the wire strand package.

Cross linked is designed to handle higher temperatures. Once exposed to operating heat this insulation is more easily melted. Whilst this particular problem can be caused by a range of issues the damage to the cable itself would attract as a minimum a c2 potentially dangerous code on an electrical inspection. Insulation degrade each time that the temperature over the specs maximum temperature shorten their life.

A full load wire does heat up due to the metallic resistance of the wire. Wires so hot you can t touch them aren t good. This could even give rise to a c1 danger present code if the. Any thermal damage melting or scorching within an electrical installation is very serious and should be rectified as a matter of urgency.

The wire then gets hotter making the outer plastic coating soft and therefore weaker which strengthens the electrical field eventually causing the coating to melt. The cda research has shown that temperatures of open wires in attics can get perilously close to the 194 f limit.