Category:1060 Electrical Conduit

MGS Information

Current General Services Specifications (MGS) By Subject

This article establishes procedures for inspecting, sampling and reporting zinc coated rigid steel conduit, intermediate metal conduit, rigid aluminum conduit, zinc coated electrical metallic tubing, rigid non-metallic conduit and fittings to be used as a raceway for wires and cables of an electrical system. Refer to Sec 1060 for MoDOT’s specifications.

For Laboratory testing and sample reporting procedures, refer to EPG 1060.4 Laboratory Testing Guidelines for Sec 1060.

1060.1 Apparatus

(a) Scales or balance accurate to within 0.5 percent of the weight (mass) of the sample to be weighed.

(b) Rule with suitable graduations to accurately measure the material to be inspected.

(c) Micrometer or vernier caliper capable of measuring to 0.001 in. (0.0254 mm).

(d) Magnetic gauge, reading range of 0-40 mils (0-1000 μm).

1060.2 Procedure

1060.2.1 Rigid Metallic Conduit and Tubing

Conduit, tubing, and fittings are to be inspected for compliance to the specified ANSI or UL standard. Regardless of the type of conduit or tubing, the material shall be examined visually both on the exterior and interior surfaces to determine if the product is free from slivers, burrs, scale, or other similar injurious defects (or a combination thereof), and if coverage of coating, if required, is complete. Conduit or tubing shall have a circular cross-section sufficiently accurate to permit the application of approved couplings and fittings and the wall thickness shall be uniform throughout. If zinc coating is required, the conduit or tubing shall be thoroughly and evenly coated with metallic zinc applied directly to the surface of the steel so that metal-to-metal contact and galvanic protection against corrosion are provided. The interior surface shall be protected by a zinc, enamel or other suitable corrosion-resistant coating as required. Weights (masses), dimensions, identification and coating requirements of the various types of conduit shall be inspected.

1060.2.1.1 Rigid Steel Conduit, Zinc Coated

The visual inspections stated in EPG 1060.2.1 Rigid Metallic Conduit and Tubing shall be performed. The inspector shall examine the conduit, nipples and elbows to ensure that they are identified with the manufacturer's name and trademark and the words "Rigid Metal Conduit" or abbreviation “GRC” (for “Galvanized Rigid Conduit”) except that closethreaded nipples need not be so identified. The conduit and couplings shall be inspected for dimensions and weight (mass) to determine conformance with the requirements of ANSI C80.1. Ten unit lengths of conduit with couplings attached shall be weighed to determine conformance with the weight (mass) requirements of conduit. A sample of conduit for each size and manufacturer shall be obtained and submitted to the Central Laboratory for the determination of weight (mass) of zinc coating. The weight (mass) of zinc coating of couplings shall be determined in the field with a magnetic gauge, in accordance with ASTM E 376. Refer to EPG 1043.2 Procedure for additional information on the proper use of the magnetic gauge. No laboratory samples of couplings are required.

1060.2.1.2 Intermediate Metal Conduit and Fittings

The visual inspection stated in EPG 1060.2.1 Rigid Metallic Conduit and Tubing shall be performed. The inspector shall examine the conduit and fittings to ensure that they are identified with the manufacturer's name or trademark and the words "Intermediate Metal Conduit" or abbreviation "IMC" and "Not for Use in Hazardous Locations" in accordance with Underwriters Laboratories Standard UL 1242. The conduit and fittings shall be inspected for dimensions to determine conformance with the requirements of ANSI C80.6 and UL 1242. A sample of conduit for each size and manufacturer shall be obtained and submitted to the Central Laboratory for the determination of weight (mass) of zinc coating. The weight (mass) of zinc coating of fittings shall be determined in the field with a magnetic gauge in accordance with ASTM E 376. Reference should also be made to EPG 1043.2 Procedure for additional information on the proper use of the magnetic gauge. No laboratory samples of fittings are required.

1060.2.1.3 Rigid Aluminum Conduit

The contractor shall furnish a manufacturer's certification showing typical test results representative of the conduit and certifying that the material supplied conforms to all of the requirements specified. The inspector shall carefully examine these certifications to ensure that the certifications are applicable and show compliance with the specification. The visual inspection noted in EPG 1060.2.1 Rigid Metallic Conduit and Tubing shall be performed. The inspector shall examine the conduit, nipples and elbows to ensure that they are identified with the manufacturer's name or trademark and the words "Rigid Aluminum Conduit" or abbreviation “RAC,” except that close-threaded nipples need not be so identified. Ten unit lengths of conduit with couplings shall be weighed and the dimensions checked for conformance with the requirements of ANSI C80.5. No Laboratory samples are required.

1060.2.1.4 Electrical Metallic Tubing, Zinc Coated

The visual inspection noted in EPG 1060.2.1 Rigid Metallic Conduit and Tubing shall be performed. The inspector shall examine the tubing to ensure that the pieces are identified by the markings “Electrical Metallic Tubing” or abbreviation "EMT", indented on the exterior surface of the tubing at intervals of not more than 3 ft. (900 mm). The letters shall not be shorter than 1/8 in. (3 mm) tall and shall be so applied that at least one marking in each l0 ft. (3000 mm) length of straight tubing will be visible when viewed from the side and with the tube in any position of rotation about its own axis. In addition, the lengths of electrical metallic tubing shall be marked with the manufacturer's name or trademark. The tubing shall be inspected for dimensions and weight (mass) determine conformance with the requirements of ANSI C80.3. Approximately 100 linear ft. (300 linear meters) of tubing shall be weighed to determine conformance with the weight (mass) requirements. A sample of each size and manufacturer shall be obtained and submitted to the Central Laboratory for the determination of weight (mass) of zinc coating.

1060.2.1.5 Fittings for Rigid Metal Conduit and Electrical Metallic Tubing

The contractor shall furnish a manufacturer's certification showing typical test results representative of the conduit and certifying that the material supplied conforms to all of the requirements specified. The inspector shall carefully examine these certifications to ensure that the certifications are applicable and show compliance with the specification. The visual inspection stated in EPG 1060.2.1 Rigid Metallic Conduit and Tubing shall be performed for each individual fitting in the shipment, or on at least 10 randomly chosen fittings, whichever is less. The inspector shall examine the conduit, nipples and elbows to ensure that they are identified with the manufacturer's name or trademark and the words "Rigid Aluminum Conduit" or "Rigid Metal Conduit", except that close-threaded nipples need not be so identified. Ten unit lengths of conduit with couplings shall be weighed and the dimensions checked for conformance with the requirements of ANSI C80.4. No Laboratory samples are required.

1060.2.1.6 Sampling

Samples of conduit or tubing for determination of weight (mass) of zinc coating shall consist of one piece not shorter than 2 in. (50 mm) long cut not less than 6 in. (150 mm) from the end of the conduit or tubing. If test results fail to comply with specification requirements, two additional samples shall be obtained for retest. If either of these samples does not comply, the lot represented will be rejected. AASHTOWARE Project (AWP) shall be used when submitting samples to the Central Laboratory. The sample record created for the laboratory sample shall include the results of tests performed in the field. In lieu of sampling, it will be permissible to accept small quantities of material based on field tests providing an acceptable manufacturer's certification is provided by the contractor showing typical test results representative of the material and certifying that the material complies with the requirements specified.

1060.2.2 Rigid Non-Metallic Conduit

The inspector shall measure physical dimensions as shown in the Underwriter's Laboratories Standards to verify the accuracy of the certifications. No laboratory samples are required.

1060.2.2.1 Polyvinyl Chloride Conduit

PVC conduit, bends, couplings, and fittings are to be inspected for compliance with the requirements of UL 651. PVC fittings are also to be inspected for compliance with the requirements of UL 514.

1060.2.2.2 High Density Polyethylene Conduit

HDPE conduit and bends are to be inspected for compliance with the requirements of ASTM F2160. HDPE couplings and fittings are to be inspected for compliance with ASTM D3350.

The contractor is required to furnish a manufacturer's certification that the material supplied conforms to the requirements specified. The inspector is to examine the certifications to ensure they are applicable.

1060.3 Reports (Records)

If the material is accepted on the basis of field tests and certification, AWP shall be used for reporting. The record shall show all pertinent information regarding the material and the certification shall be retained in the district office. The report indicates acceptance, qualified acceptance or rejection. Appropriate remarks, as described in Reporting Test Results, are to be included in the report to clarify conditions of acceptance or rejection.

All electrical conduit material reported to a contract shall be reported using the material code 1060EC, Electrical Conduit Material. The types, sizes, and lengths will then be reported using test method SAA060AA. Rigid metallic conduit and tubing submitted to the Central Laboratory will be reported using an applicable and specific material code.

Distribution of reports for materials purchased under a MoDOT purchase order is to be as described in EPG 1101 Materials Purchased by a Department Purchase Order.