Hubbell M3 specifications Installation, Vertical Mount, Inverted-Underhung

INSTALLATION

The distribution style M3 disconnect switch is made for mounting to either a single or double crossarm in an inverted (Figure 3) or vertical position (Figure 4).

NOTE: Four bolts must be used to mount on a double crossarm. Two bolts in center only may cause over bending of backstrap or base.

Position the M3 switch on the crossarms using the backstrap. Adjust the bolt heads in the switch base slots as needed to closely fit the crossarms as in Figures 3-4. Tighten mounting hardware to about 12-15 foot-pounds.

Deadend conductors using your utility’s normal practices.

Wire brush terminal pads and apply a coating of oxidation inhibitor such as Chance z.l.n. (100 or 200).

If your switch is equipped with by-pass studs, assemble between terminal pad and terminal. See Figure 5.

Wire brush connector mounting surfaces and attach to terminal pads as shown in Figure 5 with hardware facing away from insulators. Wire brush electrical conductors and apply a coating of oxidation inhibitor such as Chance z.l.n. (100 or

200)before inserting into connector. Tighten connector hardware to about 30 foot-pounds (1/2" hardware).

(STANDARD)	NUTS & WASHERS
	THIS SIDE ONLY

(STANDARD)

NUTS &

WASHERS

THIS SIDE

ONLY

Figure 4

Vertical Mount

TERMINAL PAD

BY PASS

STUD

TERMINAL

Figure 5

Figure 3 Inverted-Underhung

2

Part No. P807-0198 Rev. B 6/96