Regulations last checked for updates: Nov 25, 2024

Title 30 - Mineral Resources last revised: Nov 19, 2024
§ 18.80 - Approval of machines assembled with certified or explosion-proof components.

(a) A machine may be a new assembly, or a machine rebuilt to perform a service that is different from the original function, or a machine converted from nonpermissible to permissible status, or a machine converted from direct- to alternating-current power or vice versa. Properly identified components that have been investigated and accepted for application on approved machines will be accepted in lieu of certified components.

(b) A single layout drawing (see Figure 1 in Appendix II) or photographs will be acceptable to identify a machine that was assembled with certified or explosion-proof components. The following information shall be furnished:

(1) Overall dimensions.

(2) Wiring diagram.

(3) List of all components (see Figure 2 in Appendix II) identifying each according to its certification number or the approval number of the machine of which the component was a part.

(4) Specifications for:

(i) Overcurrent protection of motors.

(ii) All wiring between components, including mechanical protection such as hose conduits and clamps.

(iii) Portable cable, including the type, length, outside diameter, and number and size of conductors.

(iv) Insulated strain clamp for machine end of portable cable.

(v) Short-circuit protection to be provided at outby end of portable cable.

(c) MSHA reserves the right to inspect and to retest any component(s) that had been in previous service, as it deems appropriate.

(d) When MSHA has determined that all applicable requirements of this part have been met, the applicant will be authorized to attach an approval plate to each machine that is built in strict accordance with the drawings and specifications filed with MSHA and listed with MSHA's formal approval. A design of the approval plate will accompany the notification of approval. (Refer to §§ 18.10 and 18.11.)

(e) Approvals are issued only by the U.S. Department of Labor, Mine Safety and Health Administration, Approval and Certification Center, 765 Technology Drive, Triadelphia, WV 26059.

[33 FR 4660, Mar. 19, 1968, as amended at 43 FR 12314, Mar. 24, 1978; 52 FR 17514, May 8, 1987; 73 FR 52211, Sept. 9, 2008]
§ 18.81 - Field modification of approved (permissible) equipment; application for approval of modification; approval of plans for modification before modification.

(a) An owner of approved (permissible) equipment who desires to make modifications in such equipment shall apply in writing to make such modifications. The application, together with the plans of modifications, shall be filed with the U.S. Department of Labor, Mine Safety and Health Administration, Approval and Certification Center, 765 Technology Drive, Triadelphia, WV 26059.

(b) Proposed modifications shall conform with the applicable requirements of subpart B of this part, and shall not substantially alter the basic functional design that was originally approved for the equipment.

(c) Upon receipt of the application for modification, and after such examination and investigation as may be deemed necessary by MSHA, MSHA will notify the owner and the District office of the mine workers' organization having jurisdiction at the mine where such equipment is to be operated stating the modifications which are proposed to be made and MSHA's action thereon.

[33 FR 4660, Mar. 19, 1968, as amended at 43 FR 12314, Mar. 24, 1978; 60 FR 35693, July 11, 1995; 73 FR 52211, Sept. 9, 2008]
§ 18.82 - Permit to use experimental electric face equipment in a gassy mine or tunnel.

(a) Application for permit. An application for a permit to use experimental electric face equipment in a gassy mine or tunnel will be considered only when submitted by the user of the equipment. The user shall submit a written application to the Assistant Secretary of Labor for Mine Safety and Health, 201 12th Street South, Arlington, VA 22202-5452, and send a copy to the U.S. Department of Labor, Mine Safety and Health Administration, Approval and Certification Center, 765 Technology Drive, Triadelphia, WV 26059.

(b) Requirements—(1) Constructional. (i) Experimental equipment shall be so constructed that it will not constitute a fire or explosion hazard.

(ii) Enclosures designed as explosion-proof, unless already certified, or components of previously approved (permissible) machines, shall be submitted to MSHA for inspection and test and shall meet the applicable design requirements of subpart B of this part. Components designed as intrinsically safe also shall be submitted to MSHA for investigation.

(iii) MSHA may, at its discretion, waive the requirements for detailed drawings of component parts, inspections, and tests provided satisfactory evidence is submitted that an enclosure has been certified, or otherwise accepted by a reputable testing agency whose standards are substantially equivalent to those set forth in subpart B of this part.

(2) Specifications. The specifications for experimental equipment shall include a layout drawing (see Figure 1 in Appendix II) or photograph(s) with the components, including overcurrent-protective device(s) with setting(s) identified thereon or separately; a wiring diagram; and descriptive material necessary to insure safe operation of the equipment. Drawings already filed with MSHA need not be duplicated by the applicant, but shall be properly identified.

(c) Final inspection. Unless equipment is delivered to MSHA for investigation, the applicant shall notify the U.S. Department of Labor, Mine Safety and Health Administration, Approval and Certification Center, 765 Technology Drive, Triadelphia, WV 26059, when and where the experimental equipment will be ready for inspection by a representative of MSHA before installing it on a trial basis. Such inspection shall be completed before a permit will be issued.

(d) Issuance of permit. When the inspection discloses full compliance with the applicable requirements of this subpart, the Assistant Secretary will issue a permit sanctioning the operation of a single unit in a gassy mine or tunnel, as designated in the application. If the applicant is not the assembler of the equipment, a copy of the permit also may be sent to the assembler.

(e) Duration of permit. A permit will be effective for a period of 6 months. For a valid reason, to be stated in a written application, the Administrator of MSHA may grant an extension of a permit for an additional period, not exceeding 6 months. Further extension will be granted only where, after investigation, the Assistant Secretary finds that for reasons beyond the control of the user, it has not been possible to complete the experiment within the period covered by the extended permit.

(f) Permit label. With the notification granting a permit, the applicant will receive a photographic copy of a permit label bearing the following:

(1) Emblem of the Mine Safety and Health Administration.

(2) Permit number.

(3) Expiration date of the permit.

(4) Name of machine.

(5) Name of the user and mine or tunnel.

The applicant shall attach the photographic copy of the permit label, or replica thereof, to the experimental equipment. If a photograph is used, a clear plastic covering shall be provided for it.

(g) Withdrawal of permit. The Assistant Secretary may rescind, for cause, any permit granted under this subpart.

[33 FR 4660, Mar. 19, 1968, as amended at 43 FR 12314, Mar. 24, 1978; 52 FR 17514, May 8, 1987; 60 FR 35693, July 11, 1995; 67 FR 38384, June 4, 2002; 73 FR 52211, Sept. 9, 2008; 80 FR 52985, Sept. 2, 2015]
Appendix Appendix I - Appendix I to Subpart D of Part 18

LIST OF TABLES

Table No. Title
1Portable power cable ampacities—600 volts.
2Portable cord ampacities—600 volts.
3Portable power cable ampacities—601 to 5,000 volts.
4Normal diameter of round cables with tolerances in inches—600 volts.
5Nominal dimension of flat cables with tolerances in inches—600 volts.
6Nominal diameter of heavy jacketed cords with tolerances in inches—600 volts.
7Nominal diameter of three-conductor portable power cables with tolerances in inches—601 to 5,000 volts.
8Fuse ratings or instantaneous settings of circuit breakers for short-circuit protection of portable cables.
9Specifications for portable cables longer than 500 feet.
10High voltage trailing cable ampacities and outside diameters.

Table 1—Portable Power Cable Ampacities—600 Volts (Amperes Per Conductor Based on 60 °C. Copper Temperature—40 °C. Ambient)

Conductor size—AWG or MCM Single conductor 2-conductor, round or flat 3-conductor, round or flat 4-conductor 5-conductor 6-conductor
8454035302520
6605050403530
4857065554535
3958075655545
21109590756555
1130110100857565
1/01501301201009080
2/017515013511510595
3/0205175155130120110
4/0235200180150140130
250275220200160
300305240220175
350345240235190
400375280250200
450400300270215
500425320290230

Table 2—Portable Cord Ampacities—600 Volts (Amperes Per Conductor Based on 60 °C. Copper Temperature—40 °C. Ambient)

Conductor size—AWG 1-3 conductor 4-6 conductor 7-9 conductor
1415128
12201611
10252014

Table 3—Portable Power Cable Ampacities—601 to 5,000 Volts (Amperes Per Conductor Based on 75 °C. Copper Temperature—40 °C. Ambient)

Conductor size—AWG or MCM 3-conductor types G-GC and SIIC-GC 2,000 volts 3-conductor type SHD-GC 2,001-5,000 volts
66565
48585
3100100
2115115
1130130
1/0145145
2/0170170
3/0195195
4/0220220
250245245
300275275
350305305

Table 4—Nominal Diameters of Round Cables With Tolerances in Inches—600 Volts

Conductor size—AWG or MCM Single conductor 2-conductor 3-conductor 4-conductor—Types W & G 5-conductor—Types W & G 6-conductor
Types W & G twisted Type PG, 2 power Type PCG, 3 power, ground Types W & G Type PG, 3 power, ground Type PCG, 3 power, 2 control, ground Type w Tolerance
80.440.810.840.940.910.931.030.991.071.18±0.03
6.51.93.93.981.011.031.181.101.211.31±.03
4.571.081.081.101.171.201.291.271.401.52±.03
3.631.171.171.201.241.271.311.341.481.61±.03
2.661.271.271.291.341.341.391.481.611.75±.03
1.741.441.441.441.511.521.521.681.882.05±.03
1/0.771.521.521.521.651.681.681.791.962.13±.04
2/0.821.651.651.651.751.791.791.932.132.32±.04
3/0.871.771.771.771.891.931.932.072.262.49±.05
4/0.931.921.921.922.042.132.132.262.462.71±.05
2501.032.162.162.162.392.392.392.66±.06
3001.092.322.562.84±.06
3501.152.432.682.98±.06
4001.202.572.823.14±.06
4501.262.672.943.26±.06
5001.312.763.033.40±.06

Table 5—Nominal Dimensions of Flat Cables With Tolerances in Inches—600 Volts

Conductor size—AWG 2-conductor 3-conductor—Type G
Type W Type G Major Minor
Major Minor Major Minor O.D. Tolerance O.D. Tolerance
O.D. Tolerance O.D. Tolerance O.D. Tolerance O.D. Tolerance
80.84±0.040.51±0.03
6.93±.04.56±.031.02±.040.56±.031.65±0.060.67±0.05
41.05±.04.61±.031.15±.04.61±.031.85±.06.75±.05
31.14±.04.68±.031.26±.04.68±.031.99±.06.77±.05
21.24±.04.73±.031.35±.04.73±.062.10±.06.81±.05
11.40±.04.81±.031.55±.04.81±.032.43±.06.97±.05
1/01.51±.04.93±.031.67±.04.93±.03
2/01.63±.04.99±.031.85±.04.99±.03
3/01.77±.041.03±.032.00±.041.03±.03
4/01.89±.041.10±.032.10±.041.10±.03

Table 6—Nominal Diameters of Heavy Jacketed Cords With Tolerances In Inches—600 Volts

Conductor size—AWG 2-conductor 3-conductor 4-conductor 5-conductor 6-conductor 7-conductor
Diameter Tolerance Diameter Tolerance Diameter Tolerance Diameter Tolerance Diameter Tolerance Diameter Tolerance
140.64±0.020.67±0.020.71±0.020.78±0.030.83±0.030.89±0.03
12.68±.02.72±.03.76±.03.83±.03.89±.03.98±.03
10.73±.03.80±.03.84±.03.90±.031.00±.031.07±.03

Table 7—Nominal Diameters of Three-Conductor Portable Power Cables With Tolerances in Inches—601 to 5,000 Volts

Conductor size—AWG or MCM Type G-GC (nonshielded) 2,000 volts Type SHC-GC (shielded overall) 2,000 volts Type SHD-GC (individually shielded power conductors) 2,001-3,000 volts Type SHD-GC (individually shielded power conductors) 3,001-5,000 volts
Diameter Tolerance Diameter Tolerance Diameter Tolerance Diameter Tolerance
61.25 + 0.10, −0.061.39 + 0.11, −0.071.62 + 0.13, −0.081.78 + 0.14, −0.09
41.40 + .11, −.071.55 + .12, −.081.77 + .14, −.091.90 + .15, −.10
31.48 + .12, −.071.62 + .13, −.081.84 + .15, −.091.98 + .16, −.10
21.55 + .12, −.081.71 + .14, −.091.92 + .15, −.102.09 + .17, −.11
11.74 + .14, −.091.89 + .15, −.092.04 + .16, −.102.18 + .17, −.11
1/01.84 + .15, −.092.02 + .16, −.102.18 + .17, −.112.34 + .19, −.12
2/01.99 + .16, −.102.16 + .17, −.112.29 + .18, −.122.46 + .20, −.12
3/02.12 + .17, −.112.30 + .18, −.112.45 + .20, −.122.62 + .21, −.13
4/02.30 + .18, −.122.48 + .20, −.122.62 + .21, −.132.76 + .22, −.14
2502.46 + .20, −.122.70 + .22, −.13
3002.63 + .21, −.132.84 + .23, −.14
3502.75 + .22, −.142.97 + .24, −.15

Table 8—Fuse Ratings or Instantaneous Setting of Circuit Breakers for Short-Circuit Protection of Portable Cables and Cords

Conductor size—AWG or MCM Ohms/1,000 ft. at 25 °C. Maximum allowable fuse rating (amperes) Maximum allowable circuit breaker instantaneous setting (amperes) 1
142.622050
121.653075
101.0440150
8.65480200
6.410100300
4.259200500
3.205250600
2.162300800
1.1293751,000
1/0.1025001,250
2/0.0811,500
3/0.0642,000
4/0.0512,500
250.0432,500
300.0362,500
350.0312,500
400.0272,500
450.0242,500
500.0222,500

1 Higher circuit-breaker settings may be permitted for special applications when justified.

Table 9—Specifications for Portable Cables Longer Than 500 Feet 1

Conductor size—AWG or MCM Max. allowable length (feet) Normal ampacity at 60 °C. copper temperature (40 °C. ambient) Resistance at 60 °C. copper temperature (ohms)
6550500.512
460070.353
365080.302
270095.258
1750110.220
1/0800130.185
2/0850150.157
3/0900175.130
4/01,000200.116
2501,000220.098
3001,000240.082
3501,000260.070
4001,000280.061
4501,000300.054
5001,000320.050

1 Fuses shall not be used for short-circuit protection of these cables. Circuit breakers shall be used with the instantaneous trip settings not to exceed the values given in Table 8.

Table 10—High Voltage Trailing Cable Ampacities and Outside Diameters

Power conductor Ampacity * Outside diameter **
(inches)
Size AWG or kcmil Amperes per conductor SHD-GC 2001 to 5000 volts SHD-CGC 2001 to 5000 volts SHD-PCG 2001 to 5000 volts
6931.561.62
41221.681.73
31401.781.821.94
21591.871.912.03
11841.951.982.12
1/02112.082.102.26
2/02432.202.202.40
3/02792.362.362.58
4/03212.502.502.76
2503552.692.69
3003982.812.81
3504352.952.95
5005363.313.31

* These ampacities are based on single isolated conductor in air, operated with open-circuited shield for a 90 °C conductor temperature and an ambient temperature of 40 °C.

** Tolerances for the outside diameter are + 8%/−5%.

[33 FR 4660, Mar. 19, 1968; 33 FR 6345, Apr. 26, 1968, as amended at 42 FR 8373, Feb. 10, 1977; 75 FR 17549, Apr. 6, 2010; 75 FR 20918, Apr. 22, 2010]
Appendix Appendix II - Appendix II to Subpart D of Part 18

LIST OF FIGURES

Figure No. Title
1Typical layout drawing of a machine.
2Sample bill of material (to accompany layout drawing shown on figure 1)
3Material to be included with the operating instructions on or with the wiring diagram submitted to each customer.
4Sample factory inspection form.
5Typical plane joint.
6Typical combination joint.
7Typical threaded joint.
8Typical threaded straight stuffing box and packing gland lead entrance with provision for hose conduit.
9Typical slip-fit straight-type and angle-type stuffing box and packing gland lead entrance.
10Typical slip-fit angle-type stuffing box and packing gland lead entrance and typical plug for spare lead entrance hole.
Figure 2—Sample Bill of Material B. of M. No. ________ Date ____________ Revision Date 1. ____________ 2. ____________ 3. ____________ 4. ____________ 5. ____________ Bill of Material (Electrical) (Manufacturing Company) Model: (Unit Name) Approval 2G- Motor: (Manufacturing Company) Frame

______ Hp., ______ Volts, ______ Ph.,

______ Cy., ______ R.P.M.

X/P____________________(Date).

____________(Date) Extension.

Starter: (Manufacturing Company) Model

________Hp., ________Volts.

X/P (Date)

____________ Extension.

(Date) Cable—Motor to Starter:

Cond. No. ______, ______″

O.D., ______′ Long

Hose—Motor to Starter Cable:

______″ I.D., ______″ O.D., ______ ′ Long

Portable (Trailing) Cable— Type:

Cond. No. ______, ______″

O.D., ______′ Long

Hose—for Portable Cable:

______″ I.D., ______″ O.D., ______′ Long

Hose Clamps—

2 for Motor-Starter Hose conduit ______″ D

1 for Portable Cable Hose conduit ____″ D*

*Only when short length of hose is used. Trolley Tap—

(Manufacturing Company)

Model ____________________________ with ______-ampere fuse.

Rail Clamps, 2.

1 Ground Clamp, Cat. No. ______

(Manufacturing Company)

1 Return Power Conductor, Cat. No. ______

(Manufacturing Company) or—as Optional Plug on outby end of potable cable for insertion into receptacle on distribution box or equivalent with short-circuit protective device set at ______ amperes. Static-free Belt

Model

Style

Catalog No. ______,

(Manufacturing Company) Guard for Belt— Material

Overall Dimensions ______″ Long × ______″

Wide × ______″ High

Note:

The foregoing is intended as a guide. Additional electrical components used shall be completely identified.

Figure 3—Material To Be Included With the Operating Instructions—on or With the Wiring Diagram Submitted to Each Customer (Sometimes referred to as “Caution Statement”) caution

To retain “permissibility” of this equipment the following conditions shall be satisfied:

1. General safety. Frequent inspection shall be made. All electrical parts, including the portable cable and wiring, shall be kept in a safe condition. There shall be no openings into the casings of the electrical parts. A permissible distribution box shall be used for connection to the power circuit unless connection is made in fresh intake air. To maintain the overload protection on direct-current machines, the ungrounded conductor of the portable cable shall be connected to the proper terminal. The machine frame shall be effectively grounded. The power wires shall not be used for grounding except in conjunction with diode(s) or equivalent. The operating voltage should match the voltage rating of the motor(s).

2. Servicing. Explosion-proof enclosures shall be restored to the state of original safety with respect to all flame arresting paths, lead entrances, etc., following disassembly for repair or rebuilding, whether by the owner or an independent shop.

3. Fastenings. All bolts, nuts, screws, and other means of fastening, and also threaded covers, shall be in place, properly tightened and secured.

4. Renewals and repairs. Inspections, repairs, or renewals of electrical parts shall not be made unless the portable cable is disconnected from the circuit furnishing power, and the cable shall not be connected again until all parts are properly reassembled. Special care shall be taken in making renewals or repairs. Leave no parts off. Use replacement parts exactly like those furnished by the manufacturer. When any lead entrance is disturbed, the original leads or exact duplicates thereof shall be used and stuffing boxes shall be repacked in the approved manner.

5. Cable requirements. A flame-resistant portable cable bearing a MSHA assigned identification number, adequately protected by an automatic circuit-interrupting device shall be used. Special care shall be taken in handling the cable to guard against mechanical injury and wear. Splices in portable cables shall be made in a workmanlike manner, mechanically strong, and well insulated. Not more than five temporary splices are permitted in a portable cable regardless of length. Connections and wiring to the outby end of the cable shall be in accordance with recognized standards of safety.

Figure 4—Sample Factory Inspection Form Date ____________ Inspector ________________________ machine Designation: Type: ____________ Serial No. motor Manufacturer: Serial No.: ______ Type: Frame: Hp.____ F.L. Speed:____ Volts:____ Amps.__ Winding: ______ X/P No. ______ (or parts list designation). starter Manufacturer: Serial No. ______ Type: Hp. ______ Volts: ______ X/P No. ______ (or parts list designation). Short-circuit protection ______ amps. Overload-current protection ______ amps. portable cable Manufacturer: __________________________________ Type: ____________ Conductors: ______________ Length: ______ O.D. ______ MSHA No. ________ Is all wiring around machine adequately protected from mechanical damage? By hose conduit__________, Troughs Metal tubing __________, Other By removal of all sharp corners or edges? Is wiring separated from hydraulic components? Is an adequate insulated strain clamp provided for the portable cable? Are all packing glands properly packed so that 1/8-inch clearance remains between packing nut and stuffing box? Are lockwashers (or equivalent) provided for all explosion-proof enclosure fastenings? Are all plane joints securely fastened so that an 0.005-inch feeler gage cannot be inserted? Are all threaded covers secured? How? Are all electrical connections secure ________and properly insulated where necessary? Note:

Add appropriate material for each explosion-proof enclosure when more than a motor and starter are on a machine.

[33 FR 4660, Mar. 19, 1968, as amended at 42 FR 8373, Feb. 10, 1977; 42 FR 25855, May 20, 1977]
authority: 30 U.S.C. 957,961
source: 33 FR 4660, Mar. 19, 1968, unless otherwise noted.
cite as: 30 CFR 18.80