1a Appendix A Electrical Equipment Hazard Labeling.pdf

Engineering Division Electronic Equipment Build Standard Appendix A, Electrical Equipment Hazard Labeling Revision 1

A.1 Electrical Equipment Hazard Labeling

A.1.1 Definitions

Danger: Indicates a hazardous situation which, if not avoided, will result in death or serious injury. The signal word "DANGER" is to be limited to the most extreme situations. DANGER [signs] should not be used for property damage hazards unless personal injury risk appropriate to these levels is also involved.

Warning: Indicates a hazardous situation which, if not avoided, could result in death or serious injury. WARNING [signs] should not be used for property damage hazards unless personal injury risk appropriate to this level is also involved.

Caution: Indicates a hazardous situation which, if not avoided, could result in minor or moderate injury. CAUTION [signs] without a safety alert symbol may be used to alert against unsafe practices that can result in property damage only.

Notice: Is preferred to address practices not related to personal injury. The safety alert symbol shall not be used with this signal word. As an alternative to “NOTICE” the word “CAUTION” without the safety alert symbol may be used to indicate a message not related to personal injury.

A.1.2 Shock Hazard Labeling for Electrical Utilization Equipment

Enclosures that do not clearly show that they contain electrical devices shall be marked with one of the following cautionary labels or equivalent, as well as a specific voltage level label.

Equipment that is powered from more than one source shall also be labeled.

A.1.2.1 Cord-and-Plug Equipment:

Cord-and-plug equipment may be marked with the following label:

Figure 1, Clarion P/N H6010/6032-CJDHBU

A.1.2.2 Hard-wired fixed equipment:

Hard-wired fixed equipment may be marked with the following label:

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Figure 2, Clarion P/N H6010/6011-4LDHBU

A.1.3 Voltage Labels:

Figure 3, Various specific voltage level labels

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A.1.4 Multiple Sources

Equipment that is powered from more than one source may be labeled as follows:

Figure 4, Multiple voltage source label

A.2 Custom Labels

A.2.1 Standards

Custom labels should be designed based on ANSI Z535.3 Criteria for Safety Symbols and ANSI Z535.4 standard for Product Safety Signs and Labels.

A.2.2 Label Format

A safety sign or label consists of a signal word panel plus a message panel. On hazard alerting signs, in addition to a word message, a safety instruction panel may be incorporated as a place to convey lengthy instructional information (see Figure 5). A safety symbol panel may be used to communicate a part or all of the elements of a message panel. The safety symbol may appear on either side of the safety label or between the signal word and the word message when the label is in a vertical format.

Figure 5, General format of safety label

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A.2.3 Panel Format

The sign or label panels may be in a horizontal or vertical format. An instructional panel may appear below the safety label to provide safety instructions for specific hazard-related instructions or procedures.

Figure 6, Additional panel for safety instructions

A.2.4 Hazard Classification

Hazard alerting signs are classified according to the relative seriousness of the hazardous situation. The classification is based on the probability of being injured if the hazard is not avoided, and on the severity of the resulting injury. For hazard alerting signs, there are three hazard classifications that are denoted by the signal words “DANGER,” “WARNING,” and

“CAUTION.”

A.2.5 DANGER

The word DANGER shall be in safety white letters on a safety red background.

A.2.6 WARNING

The word WARNING shall be in safety black letters on a safety orange background.

A.2.7 CAUTION

The word CAUTION shall be in safety black letters on a safety yellow background.

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A.2.8 NOTICE

The word NOTICE shall be in italicized safety white letters on a safety blue background.

A.2.9 Message panel

The message panel should have either safety black lettering on a safety white background or safety white lettering on a safety black background.

A.2.10 Signal words

Signal words shall appear in sans serif letters in upper case only. The signal word NOTICE shall appear in italicized sans serif letters in upper case only.

A.2.11 Conveyed message

Safety symbols should be readily understood and should effectively communicate the message.

A.2.12 Lettering

For hazard alerting signs, lettering shall be of a size that enables a person with normal vision, including corrected vision, to read the message panel at a safe viewing distance from the hazard. For safety notice and safety instruction signs, lettering shall be of a size that enables a person with normal vision, including corrected vision, to read the message panel from the expected viewing distance.

A.2.13 Safety Alert Symbol

The safety alert symbol is a symbol that indicates a hazard. It is composed of an equilateral triangle surrounding an exclamation mark. The solid triangle portion shall be the same color as the signal word lettering, and the exclamation mark portion shall be the same color as the signal word panel background. As an alternative, the safety alert symbol may consist of a yellow triangle with a black border and black exclamation mark (figure 7). Other safety symbols may be displayed in the symbol panel to convey a distinct hazard.

Figure 7, Safety Alert Symbol

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A.3 Applicable Standards

A.3.1 NFPA 79, Section 16.2 Safety Signs for Electrical Enclosures

The provisions of the NFPA 79 standard apply to the electrical/electronic equipment, apparatus, or systems of industrial machines operating from a nominal voltage of 600 volts or less, and commencing at the point of connection of the supply to the electrical equipment of the machine.

The NFPA 79 standard provides detailed information for the application of electrical/electronic equipment, apparatus, or systems supplied as part of industrial machines that will promote safety to life and property. The following excerpts detail some of the requirements for safety markings on equipment that must conform to the NFPA 79 standard.

16.2.1* Enclosures that do not clearly show that they contain electrical devices shall be marked with a safety sign in accordance with ANSI Z535 series, which deals with product safety signs.

Note: One such safety sign is the symbol for risk of electric shock (Figure 8).

Figure 8, Symbol that represents risk of electrical shock

16.2.2 Safety signs shall be plainly visible on the enclosure door or cover.

16.2.3* Electrical equipment for industrial machines, such as industrial control panels and the enclosures of disconnecting devices, shall be marked to warn qualified persons of potential electric shock and arc flash hazards.

Note: See NFPA 70E for assistance in determining severity of potential exposures and ANSI Z535.4 for guidelines for the design of safety signs and labels for application to products.

16.2.3.1 The marking shall be located so as to be clearly visible to qualified persons before examination, adjustment, servicing, or maintenance of the equipment.

16.2.3.2 It shall be permitted to omit safety signs where the size of the enclosure precludes placement of the label on the enclosure (e.g., operator–machine interfaces, control stations, position sensors).

16.2.4 A safety sign shall be provided adjacent to the disconnecting operating handle(s) where the disconnect(s) that is interlocked with the enclosure door does not de-energize all exposed live parts when the disconnect(s) is in the open (off) position.

16.2.5 Where an attachment plug is used as the disconnecting means, a safety sign shall be attached to the control enclosure door or cover indicating that power shall be disconnected from the equipment before the enclosure is opened.

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16.2.6 Where the disconnecting means is remote from the control enclosure, a safety sign shall be attached to the enclosure door or cover indicating that the power shall be disconnected from the equipment before the enclosure is opened and that the enclosure shall be closed before the power is restored.

16.2.7 A safety sign shall be provided adjacent to the main supply circuit disconnect operating handle to warn qualified persons of potential electric arc flash hazards. The marking on the sign shall be located so as to be clearly visible to qualified persons before examination, adjustment, servicing, or maintenance of the equipment.

A.3.2 UL 508 Part 65 Cautionary Markings

The UL 508 requirements cover industrial control devices, and devices accessory thereto, for starting, stopping, regulating, controlling, or protecting electric motors. These requirements also cover industrial control devices or systems that store or process information and are provided with an output motor control function(s). This equipment is for use in ordinary locations in accordance with the National Electrical Code, NFPA 70. The UL 508 requirements cover devices rated 1500 volts or less. Industrial control equipment covered by these requirements is intended for use in an ambient temperature of 0 – 40°C (32 – 104°F) unless specifically indicated for use in other conditions.The following excerpts detail some of the requirements for safety markings on equipment that must conform to the UL 508 standard.

65.1 Cautionary markings shall be located on a part that cannot be removed without impairing the operation or appearance of the equipment.

65.2 A cautionary marking shall be prefixed with the word “CAUTION “ or “WARNING “, as applicable, in letters not less than 1/8 inch (3.2 mm) high. The remaining letters of such marking, unless specified otherwise in individual marking requirements, shall not be less than 1/16 inch (1.6 mm) high.

65.3 A cautionary marking intended to instruct the operator shall be legible and visible to the operator during normal operation of the equipment. A marking that provides servicing instructions shall be legible and visible when such servicing is being performed.

65.4 If more than one disconnect switch may be required to disconnect all power within a control assembly or compartment, the assembly or compartment shall be marked with the word “CAUTION “ and the following or the equivalent, “Risk of Electric Shock – More than one disconnect switch may be required to de-energize the equipment before servicing. “

65.5 The marking required by 65.4 shall be in a permanent location on the outside of the equipment or on a stationary fixed, nonremovable part inside the equipment. The warning marking shall not be placed inside the cover or on the connection diagram attached to the inside of a cover.

A.3.3 UL 508A Parts 55 and 67, Cautionary Markings

The UL 508A requirements cover industrial control panels intended for general industrial use, operating from a voltage of 600 volts or less. This equipment is intended for installation in ordinary locations, in accordance with the National Electrical Code, ANSI/NFPA 70, where the ambient temperature does not exceed 40°C (104°F) maximum. The following excerpts detail some of the requirements for safety markings on equipment that must conform to the UL 508A standard.

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55.1 Cautionary markings shall be located on a part that is not removable without impairing the operation or appearance of the equipment.

55.2 A cautionary marking shall be prefixed with the word “CAUTION” or “WARNING,” as applicable, in letters not less than 1/8 inch (3.2 mm) high. The remaining letters of such marking, unless otherwise specified, shall not be less than 1/16 inch (1.6 mm) high.

55.4 An industrial control panel intended to be provided with more than one supply source such that more than one disconnect switch is required to disconnect all power within the control panel shall be marked with the word “CAUTION” and the following or equivalent: “Risk of Electric Shock – More than one disconnect switch may be required to de-energize the equipment before servicing.”

Exception: This marking is not required for an isolated control circuit contact that is separately supplied.

67.4.1 An enclosure that does not clearly contain electrical parts shall be marked, “CAUTION – High Voltage – ___V”, or with a black lightning flash on a yellow background within a black triangle as in Figure 9, or an equivalent marking.

Figure 9, Lightning flash on a yellow background

Exception: Equipment provided with external electrical devices such as disconnect handles and operator controls are not required to comply with this requirement.

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A.4 References

American National Standards Institute. ANSI Z535.4 American National Standard for Product Safety Signs and Labels, 2011 Ed. Rosslyn, VA: National Electrical Manufacturers Association, 2011

National Fire Protection Association. NFPA 79 Electrical Standard for Industrial Machinery, 2012 Ed.

Quincy, MA: National Fire Protection Association, 2011.

Underwriters Laboratories. Standard for Safety, Industrial Control Equipment, UL508. Northbrook, IL:

Underwriters Laboratories, 1999.

Underwriters Laboratories. Industrial Control Panels, UL508A. Northbrook, IL: Underwriters Laboratories, 2001.

A.5 Revision Log

Date, Revision # Brief Description of Revision / Changes Sec. #, Parag.

7/21/2014 Revision 1

Initial version All

DOCUMENT INFORMATION

Title: Requirements Management

Document number

Revision number 1

Publication date: 7/21/2014

Effective date: 7/21/2014

Next review date: 7/21/2015

Last Edited By: pbong@lbl.gov

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