Also consult with the local plant to determine if established Area Classifications apply.

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1 Overview The Design Guideline provides the Project Engineer or Designer of Record (DoR) with uniform definitions for plant area classifications. The classifications guide the selection and design of electrical systems, control systems, and associated equipment. Internal and external engineering designers must incorporate these requirements into any design or specification that involves area classifications. Table of Contents 1. Overview 2. Design 3. Appendix NEMA Descriptions 4. Summaries 1. Overview Consider all standards described in this document mandatory unless otherwise identified as optional or preferred. Any variance from GMI requirements or preferences requires prior GMI Engineering approval. Obtain approval from the engineer that issued this document or has been designated as responsible for project deliverables. GMI will provide and document specific project requirements and approvals. Always contact the local authority having jurisdiction (AHJ), such as the building inspection authority and local fire marshal office to determine the codes and issues involved with identifying s. Also consult with the local plant to determine if established s apply. If classified areas overlap, the standards for the area having the greater degree of protection shall govern. CIS_313_ Design Guidelines _WHQ.doc, 0, October

2 Design 2. Design This section describes the classifications that have been standardized. Other standards and recommended practices use these classifications to specify equipment, installation, and sanitary provisions for both design and installation. Office Area (NEMA 1, 1G, or 12) Warehousing and Distribution Area (NEMA 1, 1G, or 12) Dry Production Area (NEMA 12 or NEMA 12SS) Combustible Dust Area (CLASS II, DIV 2) Wet Production Area (NEMA 4, NEMA 4SS or NEMA 4PL) Wet Corrosive Area (NEMA 4X, NEMA 4XSS or NEMA 4XPL) Dedicated Equipment Room (NEMA 1, 1G, or 12) Other Area (NEMA 1, 1G, or 12) Exterior Areas (NEMA 3R, 4, or 4X) Classify all areas of the plant based on the protection required for electrical equipment and sanitary requirements. Label areas on plant drawings using these standardized classifications. Using the standard designations, record plant area classifications and maintain them as a separate level on the plant plan drawings. 2.1 Office Area Office areas are used by supervisory, clerical, or other supporting personnel, and are not exposed to production conditions. Typical locations might include administrative offices and production supervisors offices. Office Areas require minimal protection of electrical and controls equipment. Requirements primarily protect interactions between personnel and the equipment. Use "OFFICE" as the standard designation. CIS_313_ Design Guidelines _WHQ.doc, 0, October

3 Design 2.2 Warehousing and Distribution Area Warehousing and distribution areas are used to store, ship, or receive products and materials. In general, protective packaging maintains material and product integrity in these areas. Design and install electrical and controls equipment to protect them from material handling equipment. If environmental factors such as dust, dirt, and temperature are a factor, rate a warehousing and distribution area as a dry production area. Use WAREHOUSING" as the standard designation. 2.3 Dry Production Area Dry production areas are not exposed to water wash down. Typical locations might include dry bulk ingredient storage areas, packaging lines, and motor control and equipment rooms. Electrical and control equipment must be protected against dust, dirt, and dripping or splashing liquid. Generally, equipment in dry production areas require NEMA 12 protection. Use "NEMA 12" as the standard designation where stainless steel is not required for sanitation. Use "NEMA 12SS where stainless steel enclosures are required. 2.4 Combustible Dust Area GMI policy and design practices dictate that plants shall NOT have any areas that require NEC Class II classifications for normal operations. Plant areas are designed to remove metal particles, static build-up, and other potential sources of ignition during normal operations. In addition, GMI procedures require periodic cleaning to avoid buildup of materials that might lead to hazardous conditions. Use NFPA document 499 (Classification of Combustible Dusts and of Hazardous [Classified] Locations for Electrical Installations in Chemical Process Areas, 2004 Edition) to determine the existence, nature and extent of hazards in those areas containing combustible dusts. CIS_313_ Design Guidelines _WHQ.doc, 0, October

4 Design In cases where occasional equipment malfunctions might be sufficient to interfere with safe electrical operation, classify the area as NEC Class II, Division 2. Examples include flour silo blower rooms and sugar grinding equipment. Use "CLASS II, DIV 2" as the standard designation. 2.5 Wet Production Area Wet production areas have one or more of the following characteristics: Line equipment is cleaned by periodic wash down. Water or other fluid is used in the transport, processing, or cleaning of product. Equipment is exposed to steam vapor. Equipment is NOT regularly exposed to corrosive material. Examples of wet production areas include pizza process operations and wet mix rooms for prepared dough. Equipment in these areas generally require NEMA 4 protection. Use the following designations: "NEMA 4SS" where stainless steel is required. "NEMA 4PL" where plastic enclosures are required. "NEMA 4" where stainless steel, plastic, or epoxy-painted steel may be used. 2.6 Wet Corrosive Area Wet corrosive areas have one or more of the following characteristics: Chemicals are present (such as brine or acid) that cause direct corrosive action. Dry compounds are stored such that dust accumulated over time combines with moisture or other materials to form corrosive materials. The area is subjected to high-pressure steam that can oxidize and corrode metal components. CIS_313_ Design Guidelines _WHQ.doc, 0, October

5 Design Examples of wet corrosive areas include caustic peeling for potato processing and cleaning material storage. Equipment in these areas generally require NEMA 4 protection. Use the following designations: "NEMA 4SS" where stainless steel is required. "NEMA 4PL" where plastic enclosures are required. "NEMA 4" where stainless steel, plastic, or epoxy-painted steel may be used. 2.7 Dedicated Equipment Rooms The dedicated equipment rooms classification applies to areas where electrical equipment does not require special water or dust containment and are the room environment maintains acceptable humidity and temperature conditions (for example, a motor control room). Use "NEMA 1" as the standard designation. 2.8 Other Plant Areas Classify areas of the plant that do not meet the criteria for any other classifications as not rated. Use "NOT RATED" as the standard designation. CIS_313_ Design Guidelines _WHQ.doc, 0, October

6 Appendix NEMA Descriptions 3. Appendix NEMA Descriptions The following descriptions are copied verbatim from ANSI/NEMA Publication 250, Enclosures for Electrical Equipment (1000 volts maximum). Refer to the source document for a complete description and application of NEMA enclosure standards. NEMA 1 Enclosures are intended for indoor use primarily to provide a degree of protection against contact with the enclosed equipment or locations where unusual service conditions do not exist. NEMA 1G Enclosures are intended for indoor use primarily to provide a degree of protection against contact with the enclosed equipment or locations where unusual service conditions do not exist. Equipment contains neoprene or other suitable gasketing material. NEMA 4 Enclosures are intended for indoor or outdoor use primarily to provide a degree of protection against windblown dust and rain, splashing water, and hose-directed water; undamaged by the formation of ice on the enclosure. They are designed to meet hose down, dust, external icing, and rust-resistance tests. They are not intended to provide protection against conditions such as internal condensation or internal icing. Enclosures are made of heavy gauge stainless steel, cast aluminum or heavy gauge sheet steel, depending on the unit and the size. Cover has a synthetic rubber gasket. NEMA 4X Enclosures are intended for indoor or outdoor use primarily to provide a degree of protection against corrosion, windblown dust and rain, splashing water, and hosedirected water; undamaged by the formation of ice on the enclosure. They are designed to meet hose down, dust, external icing, and rust-resistance tests. They are not intended to provide protection against conditions such as internal condensation or internal icing. CIS_313_ Design Guidelines _WHQ.doc, 0, October

7 Appendix NEMA Descriptions NEMA 9 GMI policy and design practices dictate that plants shall NOT have any areas that require NEC Class II classifications for normal operations. This classification is listed for reference only. Type 9 enclosures are intended for indoor use in locations classified as Class II, Groups E, F, or G, Division I, as defined in the National Electric Code. Type 9 enclosures are designed to be capable of preventing the entrance of dust. Enclosed heat generating devices are designed not to cause external surfaces to reach temperatures capable of igniting or discoloring dust on the enclosure or igniting dust-air mixtures in the surrounding atmosphere. Enclosures are designed to meet the dust penetration and temperature design tests, and aging of gaskets. NEMA 12 Enclosures are intended for indoor use primarily to provide a degree of protection against dust, falling dirt, and dripping non-corrosive liquids. They are designed to meet drip, dust, and rust-resistance tests. They are not intended to provide protection against conditions such as internal condensation. Type 12 enclosures may be used in locations classified as Class II, Group G, and Division 2. CIS_313_ Design Guidelines _WHQ.doc, 0, October

8 Summaries 4. Summaries Enter information in these tables to track revisions to the master document. NOTE: In the Entry column, enter your information between the dashes. The entries automatically update matching document properties. Document Property Entry Master Owner Master Number -0- -Steve Curtis- Increment revision numbers by one. Master Date -6/15/05- Number Date Owner Summary (Brief description of major changes) 0 6/15/2005 Steve Curtis Initial Development CIS_313_ Design Guidelines _WHQ.doc, 0, October

9 Summaries 4.1 Plant Customization Tracking Enter information in these tables to track revisions to plant customized documents. NOTE: In the Entry column, enter your information between the dashes. The entries automatically update document properties. Document Property Entry Plant Code -XXX- Plant Owner -Enter Name- Plant Number Plant Date -3/29/05- Use the following format for the Plant Number: <Master Number>.<Plant Number> Number Date Owner Summary (Brief description of major changes) 0 CIS_313_ Design Guidelines _WHQ.doc, 0, October