Mich. Admin. Code R. 408.30537a

Current through Vol. 24-10, June 15, 2024

Section R. 408.30537a - Wiring methods

Rule 537a.

Section E3803.6 and tables E3801.4, and E3802.1 are amended to read as follows:

E3803.6. Raceway seals. Conduits or raceways shall be sealed or plugged at either or both ends where moisture will enter and contact live parts. Sealants shall be identified for use with the cable insulation, shield, or other components.

TABLE E3802.1

GENERAL INSTALLATION AND SUPPORT REQUIREMENTS FOR WIRING METHODS^{a,b, c, d, e, f, g, h, i, j, k}

INSTALLATION REQUIREMENTS (Requirement applicable only to wiring methods marked "A")	AC MC	EMT IMC RMC	ENT	FMC LFC	NM UF	PVC	SE	SR^a
Where run parallel with the framing member or furring strip, the wiring shall be not less than 1 1/4 inches from the edge of a furring strip or a framing member such as a joist, rafter, or stud or shall be physically protected.	A	-	A	A	A	-	A	-
Bored holes in framing members for wiring shall be located not less than 1 1/4 inches from the edge of the framing member or shall be protected with a minimum 0.0625-inch steel plate or sleeve, a listed steel plate, or other physical protection.	A^k	-	A^k	A^k	A^k	-	A^k	-
Where installed in grooves, to be covered by wallboard, siding, paneling, carpeting, or similar finish, wiring methods shall be protected by 0.0625-inch-thick steel plate, sleeve, or equivalent, a listed steel plate or by not less than 1 1/4-inch free space for the full length of the groove in which the cable or raceway is installed.	A	-	A	A	A	-	A	A
Securely fastened bushings or grommets shall be provided to protect wiring run through openings in metal framing members.	-	-	A^j	-	A^j	-	A^j	-
The maximum number of 90-degree bends shall not exceed 4 between junction boxes.	-	A	A	A	-	A	-	-
Bushings shall be provided where entering a box, fitting, or enclosure unless the box or fitting is designed to afford equivalent protection.	A	A	A	A	-	A	-	A
Ends of raceways shall be reamed to remove rough edges.	-	A	A	A	-	A	-	A
Maximum allowable on center support spacing for the wiring method in feet.	4.5^b,c	10^l	3^b	4.5^b	4.5ⁱ	3^{d, l}	2.5^e	-
Maximum support distance in inches from box or other terminations.	12^{b, f}	36	36	12^{b, g}	12^{h, i}	36	12	-

For SI: 1 inch = 25.4 mm, 1 foot = 304.8 mm, 1 degree = 0.0175 rad.

a. Installed in accordance with listing requirements.

b. Supports not required in accessible ceiling spaces between light fixtures where lengths do not exceed 6 feet.

c. Six feet for MC cable.

d. Five feet for trade sizes greater than 1 inch.

e. Two and one-half feet where used for service or outdoor feeder and 4.5 feet where used for branch circuit or indoor feeder.

f. Twenty-four inches for Type AC cable and 36 inches for interlocking Type MC cable where flexibility is necessary.

g. Where flexibility after installation is necessary, lengths of flexible metal conduit and liquidtight flexible metal conduit measured from the last point where the raceway is securely fastened shall not exceed: 36 inches for trade sizes &frac12 through 1 1/4, 48 inches for trade sizes 1 &frac12 through 2 and 5 feet for trade sizes 2 &frac12 and larger.

h. Within 8 inches (203 mm) of boxes without cable clamps.

i. Flat cables shall not be stapled on edge.

j. Bushings and grommets shall remain in place and shall be listed for the purpose of cable protection.

k. See Section R502.8 and R802.7 for additional limitations on the location of bored holes in horizontal framing members.

l. Raceways may be unsupported where the raceway is not more than 900 millimeters (36 inches) long and remains in unbroken lengths (without coupling).

Such raceways shall terminate in an outlet box, junction box, device box, cabinet, or other termination at each end of the raceway.

Mich. Admin. Code R. 408.30537a

2010 AACS; 2015 AACS