Protection of Electrical Equipment

Instrumentation, PLC, DCS, Control systems, Electric motors, VFDs, Cabling, etc.
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luca
Posts: 6
Joined: 26 Jul 2025, 14:46
Area of interest: Electrical Engineering

Protection of Electrical Equipment

Post by luca »

Please share your thoughts on necessary protection of electrical equipment in petrochemical industry.
The applicable codes, standards, and the guidelines...
tuan
Posts: 63
Joined: 27 May 2025, 14:07
Area of interest: Chemical Engineering

Re: Protection of Electrical Equipment

Post by tuan »

This starts with the calssification of hazardous area classification as this dictate the type of electrical equipment and protection methods required.

Zone 0: Explosive atmosphere present continuously or for long periods. (Requires Category 1 equipment - EPL Ga/Da)
Zone 1: Explosive atmosphere likely to occur in normal operation. (Requires Category 2 equipment - EPL Gb/Db)
Zone 2: Explosive atmosphere not likely to occur in normal operation, and if it does, only for a short period. (Requires Category 3 equipment - EPL Gc/Dc)

Then a thought is to be given to the hazardous materials present:
Groups: Classify the specific type of hazardous material (e.g., Acetylene, Hydrogen, Propane for gases; Metal dusts, Carbonaceous dusts, Flour for dusts).
Temperature Classes (T-Codes): Indicate the maximum surface temperature of the equipment, which must be below the auto-ignition temperature of the specific hazardous material present.

This would then be connected with the type of protection of electric equipemt.

Looking at the governing body, the International Electrotechnical Commission (IEC) develops global standards for electrical and electronic products, including those for hazardous areas. Key standards include the IEC 60079 series for explosive atmospheres.
IEC 60079-10-1: Classification of explosive gas atmospheres.
IEC 60079-10-2: Classification of explosive dust atmospheres.
IEC 60079 series (various parts): Cover different protection techniques (Ex d, Ex e, Ex i, etc.).

API 500 and API 540 provides some good inputs as well.
luca
Posts: 6
Joined: 26 Jul 2025, 14:46
Area of interest: Electrical Engineering

Re: Protection of Electrical Equipment

Post by luca »

What about API 505 as a reference here?
ww2i
Posts: 8
Joined: 20 Nov 2025, 21:06
Area of interest: Petroleum Engineering

Re: Protection of Electrical Equipment

Post by ww2i »

The scope itself is different however addresses the same issue.
API 500 & 505 addresses the hazardous area classification on division & zone wise basis.
API 540 itself addresses the details on the design, selection etc. part.
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