Voltage rating of control cables in explosion-proof areas
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In accordance with GB50257-2014, Code for Construction and Acceptance of Electrical Installations in Explosive and Fire-Hazardous Environments, clause 5.1.3 states that the rated voltage of low-voltage cables and insulated wires used in explosive hazard environments must be higher than the operating voltage of the circuit, and shall not be lower than 500V. However, when purchasing such cables, manufacturers only offer control cables with a rated voltage of 450/750V. How does everyone think about this?
450/750V means that the AC voltage withstand rating is 450V, with a peak value of 750V. As long as the maximum voltage of the control cable is 400V, cables with a rating of 450/750V fully meet the requirements. But I don’t know why it has to be at least 500V.
Control cables with voltages above 500V are also common
It can be used; explosion-proof cables need to have an armor layer and flame-retardant properties as well
Ordinary cables are not explosion-proof cables; it has nothing to do with whether they are armored or not
The standard probably doesn’t mention the concept of explosion-proof cables. It’s just that if explosion protection is required, it is made in an armored version. Intrinsic safety types do not require shielding.
Now I also have questions about the option of using cables and wires rated for over 500V? What’s been written is complete nonsense; standard GB50257-2014 is based on GB 50058-1992, not GB 50058-2014. This term is no longer used in GB 50058-2014. For insulated wires, I haven’t seen any with voltages higher than 500V; cables of 0.6/1 KV can use YJV type.