You're on the right track with your research, and it's great that you're focusing on safety in a Class 1 Division 1 location! Here's a breakdown of what you need to consider regarding rubber cord for your portable mixer, along with some key points and resources

Key Considerations for Rubber Cord in Class 1 Div 1 Locations

1. Suitability of Equipment

The

entire portable mixer must be approved for Class 1 Division 1 environments. This means the motor, switches, and enclosure are all intrinsically safe or explosion-proof. Simply using appropriate cord isn't enough. If the mixer itself isn't rated, it cannot be used in this location. Look for markings on the equipment that explicitly state the hazardous location rating (e.g., "Class I, Division 1, Groups C & D").2. Cord Type and Requirements

You are correct that the cord needs to be

extra-hard usage and continuous. This means no splices or junctions are permitted along the cord's length. Equipment Grounding Conductor

Absolutely essential. The grounding conductor must be properly connected to the mixer's chassis and the power source's ground.

Type SOOW

is often recommended for this type of application, as it is rated for hard usage and is oil and water resistant. Other types like SJOOW may also be acceptable but verify that they meet the "extra-hard usage" requirement.

UL Listing

The cord must be UL listed or have another nationally recognized testing laboratory (NRTL) certification. The listing will specify its voltage and temperature rating.3.

Maximum Length

There isn't a specific maximum length dictated by the NEC for Class 1 Division 1 regarding cord length. However, the length should be kept as short as reasonably practical to minimize voltage drop and the risk of physical damage.

Voltage Drop

Long cord lengths cause voltage drop, which can reduce the mixer's performance and potentially damage the motor over time. Calculate the voltage drop based on the mixer's current draw, the cord's gauge (AWG), and the cord length. Ensure the voltage drop remains within acceptable limits (typically 3-5%).4.

Strain Relief

Proper strain relief must be provided at both ends of the cord (where it connects to the mixer and the power source). This prevents stress on the wire connections and ensures the cord is securely anchored.5.

Power Source

The power source must be compatible with the Class 1 Division 1 location. This typically means explosion-proof receptacles and plugs. The plug must be of the grounding type, and the receptacle must be properly grounded.

Where to Find Specific Requirements (NEC and Other Standards) NEC (National Electrical Code)



Article 500-505

Contains the general requirements for hazardous (classified) locations. Pay close attention to Article 501 for Class I locations.

Article 400

Covers flexible cords and cables.

Article 250

Grounding and Bonding. Extremely important for safety.

NFPA 70E (Standard for Electrical Safety in the Workplace)

Addresses safety-related work practices for electrical hazards, including those in hazardous locations.

Manufacturer's Instructions

Always follow the manufacturer's instructions for the portable mixer and the cord.

Important Considerations and Warnings Competent Person

The selection, installation, and maintenance of electrical equipment in hazardous locations must be performed by qualified and competent individuals who are thoroughly familiar with the applicable codes and standards.

Permitting and Inspections

Consult with your local authority having jurisdiction (AHJ) regarding permitting and inspection requirements. They may have specific local amendments or interpretations of the NEC.

Intrinsically Safe Barriers

Consider the use of intrinsically safe (IS) barriers where applicable. IS barriers limit the energy available in the circuit, preventing ignition.*

Regular Inspections and Maintenance

Implement a regular inspection and maintenance program for the portable mixer and its cord to identify and address any potential issues (e.g., damage to the cord, loose connections) promptly.

In summary


Verify that the entire mixer is approved for Class 1 Div 1.2. Use extra-hard usage, continuous cord with an equipment grounding conductor (SOOW is often recommended).
3. Keep the cord length as short as practical, considering voltage drop.4. Ensure proper strain relief at both ends.
5. Use an appropriate power source (explosion-proof receptacle and plug).6. Consult the NEC, NFPA 70E, and the manufacturer's instructions.
7. Use competent personnel for installation and maintenance.This is a complex topic, and it's essential to err on the side of caution. Consulting with a qualified electrical engineer or a certified hazardous locations specialist is highly recommended to ensure the safety of your installation. Flag for review