How do I choose an arc flash suit?
Your arc flash PPE should contain a tag that has an arc thermal protective value (ATPV) rating (also listed in cal/cm2). The ATPV rating means that the rated PPE will protect the wearer from arc flash energies up to that ATPV value.
What is arc flash suit?
Arc flash suits protect electrical workers from serious injuries or sicknesses that are caused from electrical and other common at-work hazards. Arc flash suits consist of a variety of electrical safety clothing including coveralls, leggings, aprons, footwear, smocks, gloves, pants, hoods, jackets, and vests.
When should you wear an arc flash suit?
Employees shall wear arc-rated clothing wherever there is possible exposure to an electric arc flash above the threshold incident energy level for a second degree burn of 1.2 calories per square centimeter (cal/cm2).
What voltage is arc flash PPE?
Each piece of equipment operating at 50 volts or more and not put into a deenergized state must be evaluated for arc flash and shock protection. This evaluation will determine the actual boundaries (i.e. prohibited, limited, restricted etc) and will inform the employee of what PPE must be worn.
What are the 4 categories of PPE?
A brief overview of each of these 4 PPE Categories is listed below:
- PPE Category 1: Minimum Arc Rating 4 cal/cm2
- PPE Category 2: Minimum Arc Rating 8 cal/cm. …
- PPE Category 3: Minimum Arc Rating 25 cal/cm. …
- PPE Category 4: Minimum Arc Rating 40 cal/cm.
How many arc flash PPE categories are there?
four Arc Flash PPE Categories
The National Fire Protection Association (NFPA) uses four Arc Flash PPE Categories to classify ranges of arc flash hazards, and the corresponding requirements for PPE.
What is arc resistant?
Arc resistance is defined as the ability of an insulating material to withstand a high voltage electric arc and resist the formation of a conducting path along its surface. This conducting path is the result of thermal and chemical decomposition and erosion of the material.
What voltage is needed for PPE?
If this is infeasible, then some level of PPE will be required before removing covers, depending on the voltage. Most common voltages in the United States are 120/240 volts single phase and 120/208 and 277/480 volts 3 phase, and in Canada the 575 volts is the most common 3 phase power system.
What does 4 cal cm2 mean?
The ATPV is measured in cal/cm2, and it’s defined as the maximum incident heat energy that a fabric can absorb and lessen the injury to a 2nd degree burn. If the worker is exposed to a potential incident heat energy level of less than 4.0 cal/cm2, the proper ATPV clothing system is 4 cal/cm2.
How do you determine PPE category?
The Arc Flash Personal Protective Equipment (PPE) Category is determined by consulting the PPE tables in article 130.7 of the NFPA 70E standard. PPE categories range from 1 to 4 (with four having the highest incident energy rating and requiring the most protective gear).
What PPE should be worn when the incident energy is less than 1.2 cal cm 2?
NFPA 70E 130.7(C)(6), Body Protection, states, “Employees shall wear arc-rated clothing wherever there is a possible exposure to an electric arc flash above the threshold incident energy level for a second-degree burn [1.2 cal/cm2].”
What is the PPE category that presents the least amount of arc flash risk?
PPE CAT 1
PPE CAT 1 represents the lowest level in which Arc Rated PPE s required.
What PPE is required inside the arc flash hood?
Personal Protective Equipment Requirements for Arc Flash Protection
| Category | Energy Level | PPE Requirements |
|---|---|---|
| 0 | ≤2 cal/cm² | Non-melting or untreated natural fiber |
| 1 | 4 cal/cm² | Fire Resistant (FR) shirt and pants |
| 2 | 8 cal/cm² | Fire Resistant shirt and pants, cotton underwear |
| 3 | 25 cal/cm² | Two layers Fire Resistant clothing, cotton underwear |
Which of the following methods can be used in selecting arc flash PPE?
NFPA 70E permits either of two methods be used when selecting arc flash PPE. The PPE category method, which relies on tables, or the incident energy analysis method, which calls for an electrical power system analysis to be performed by electrical engineers.
What are the two methods for selecting PPE with the proper arc rating?
Determine PPE level
This arc rating for a piece of equipment is calculated based on the working distance, available fault current, and length of exposure, as well as other factors. There are two basic methods of determining the arc rating: tables or incident energy calculations.
Which method of determining arc flash PPE is the preferred method because it is considered to be more precise?
Arc flash hazard calculation analysis method. An engineering assessment provides more accurate results in determining arc flash hazard/risk categories and the resulting PPE selection.
