Heavy duty explosion-proof extension cord 50 ft / 15.24 m, 10/3 AWG, 20 A / 125 V, NEMA 20A connection

Explosion-Proof 50 ft Extension Cord — 20 A / 125 V, 10/3 AWG, Explosive Atmospheres

The Allegro heavy duty explosion-proof extension cord, 50 ft / 15.24 m, is designed to safely power the explosion-proof fans and blowers used in confined spaces with an explosion hazard. It operates at 20 A / 125 V with a rugged 10/3 AWG wire gauge and is weather resistant across a wide range of -40°F to 221°F (-40°C to 105°C). Its outer jacket is flame, water and oil resistant while remaining flexible and abrasion resistant. This cord meets CSA specifications. It is classified Class I, Division 1&2 groups B, C, D and Class II, Division 1&2 groups F and G. It is ideal for use with explosion-proof fans or blowers such as the 12" explosion-proof blower kit (RA9548-25EX). Allegro Industries manufacturer's code: 9540-50EX.

Important note on group F: do not use in the presence of conductive dusts. Most coal dust is not electrically conductive, but the nature of the dusts present must be validated before use.

Cord Specifications

• Length: 50 ft / 15.24 m
• Wire type: 10/3 AWG
• Maximum amperage: 30 A
• Voltage: 125 V
• Male connector: NEMA 20 A, explosion-proof type
• Female connector: NEMA 125 VAC, 20 A, with spring-loaded protective cover
• Approval: meets CSA; classified Class I, Division 1&2 groups B, C, D and Class II, Division 1&2 groups F and G
• Operating temperature: -40°F to 221°F (-40°C to 105°C)
• Flame, water, oil and abrasion resistant jacket
• Weight: 15.5 lb / 7.03 kg
• Color: black

Advantages of the RA9540-50EX Explosion-Proof Extension Cord

Electrical Safety in Explosive Atmospheres

In a confined space classified as an explosion hazard, every electrical component must be designed to never produce a spark capable of igniting the gases, vapours or dusts present. The RA9540-50EX is classified Class I, Division 1&2 groups B, C, D (flammable gases and vapours) and Class II, Division 1&2 groups F and G (combustible dusts). Its explosion-proof connectors and certified construction make it a safe link in the power chain of an explosion-proof blower.

Heavy Duty Construction and Wide Thermal Range

The 10/3 AWG wire supports a maximum amperage of 30 A and minimizes voltage drop over 50 ft. The jacket resists flames, water, oil and abrasion, and stays operational from -40°F to 221°F — a range well above standard cords, suited to demanding industrial environments.

Protected Female Connector

The NEMA 125 VAC 20 A female connector has a spring-loaded protective cover that shields the contacts from moisture, dust and debris when the outlet is not in use — an essential detail for maintaining the explosion-proof integrity of the connection.

Grounding — Complete Instructions (Vital)

When equipment is used in explosive environments, it is essential to ensure proper grounding: the slightest spark can cause a disaster. This extension cord is part of the electrical continuity chain that must lead to ground.

To achieve proper grounding, all equipment connected together must have electrical continuity leading to ground, with zero or very low ohmic resistance. Continuity must be verified across the entire chain: from the end of the ventilation duct, through the explosion-proof blower, the explosion-proof extension cord, the explosion-proof plug, to the electrical panel. A competent electrician must validate this grounding before any use in an explosive atmosphere.

FAQ — Allegro RA9540-50EX Explosion-Proof Extension Cord

What is the difference between the RA9540-50EX and the RA9540-60EX?

The RA9540-50EX operates at 125 V, while the 220 VAC version (RA9540-60EX) powers explosion-proof equipment at higher voltage. Both use a 10/3 AWG wire and share the same explosion-proof classification. Choose the voltage matching your blower.

Can I use a standard extension cord instead?

No, never in an explosive atmosphere. A standard cord (RA9540-50) is not explosion-proof and could produce an ignition spark. Use only a cord classified for the applicable zone.

What does the group F warning mean?

Group F concerns carbon-based combustible dusts. The warning specifies not to use in the presence of conductive dusts. Most coal dust is not electrically conductive, but the exact nature of the dusts present must be assessed by a competent person before use.

Complementary Equipment Suggestions for Your Explosion-Proof Ventilation

To optimize your explosion-proof setup, first see the 12" explosion-proof axial blower kit with conductive duct (RA9548-25EX) that this cord powers, as well as the 12" antistatic explosion-proof flexible duct (RA9550X). Add the galvanized steel connector (RACONN) and the manhole entry airflow assembly (RA9510).

Under "Accessories" at the bottom of the page, complete your equipment with the Altair 4X 4-gas detector (DETEC4GC) essential before any entry, the manhole barrier (EPTBB) to secure the perimeter, and the Peakworks 6 D-ring confined space harness (FPH2000APLE) stored in its carry bag (FPBAG).

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