Vent Hood and Pull Box Installation

This section contains instructions for installing a vent hood over the top plate vents on an MCC.

1. Turn off all power supplying this equipment before working on or inside the equipment, and follow lockout/tagout procedures. Always use a properly rated voltage sensing device to confirm the power is off.

2. Remove the 3/8 in. (9.525 mm) bolts and washers that hold the lifting angle in place, and then remove the lifting angle.

   NOTE: The vent hood is attached to the top of the MCC section for shipping. It must be relocated during MCC installation.

3. Remove the two 10-32 screws that secure the vent hood and top plate to the top of the MCC section.

4. Remove the vent hood and reinstall the 10-32 screws into the top plate.

5. Position the vent hood on the top of the MCC section as shown in Reposition and Attach the Vent Hood.

   Reposition and Attach the Vent Hood

   

6. Secure the vent hood using the two 3/8 in. (9.525 mm) bolts and washers removed in step 2. Torque the bolts to 28–33 lb-in. (3.164–3.729 N•m).

This section contains instructions for installing pull boxes on low voltage MCCs. Pull boxes are either 12 or 18 in. (304.8 or 457.2 mm) high and mount on the top of the MCC.

1. Turn off all power supplying this equipment before working on or inside the equipment, and follow lockout/tagout procedures. Always use a properly rated voltage sensing device to confirm power is off.

2. Remove the 3/8 in. (9.525 mm) bolts and washers that hold the lifting angle in place, and then remove the lifting angle.

3. Remove the 10-32 screws securing the top closing plate to the top of the MCC section.

4. Remove the top closing plate from the structure.

5. Remove the front panel from the pull box. Position the pull box on top of the MCC section as shown in Install the Pull Box.

   Install the Pull Box

   

6. Install the two 3/8 in. (9.525 mm) bolts and washers that were removed in step 2. Place them through the pull box lower side channels and into the top of the MCC section. Torque the bolts to 28–33 lb-in. (3.164–3.729 N•m).

7. Re-install the pull box front panel removed in step 5 and the top closing plate removed in step 4 (see Install the Pull Box).

Follow the same instructions for standard pull box installation, except remove and discard the top closing plate from the MCC section. The vented pull box comes with a solid top plate.

1. Turn off all power supplying this equipment before working on or inside the equipment, and follow lockout/tagout procedures. Always use a properly rated voltage sensing device to confirm power is off.

2. Remove the 3/8 in. (9.5 mm) bolts and washers that hold the lifting angle in place, and then remove the lifting angle.

3. Remove the 10/32 in. (4.8 mm) screws and vented hood.

4. Remove the 10/32 in (4.8 mm) screws from the top horizontal wireway cover, and then remove the wireway cover.

5. Remove the pull box front cover for installation access (see ArcBlok 1200 Main Breaker Pull Box).

   ArcBlok 1200 Main Breaker Pull Box

   

6. Install 1/2 in. (12.7 mm) bolts and washers from inside the MCC section through the top closing plate and to the front pull box channel. Complete the connection with a washer and nut on the inside of the pull box.

7. Install two 1 /4 in (6.4 mm) screws on the pull box rear channel and to the top closing plate.

8. Install the two 3/8 in. (9.5 mm) bolts and washers that were removed in step 2. Place them through the lower side flanges of the vented hood, and into the top of the MCC section. Torque the bolts to 28–33 lb-in. (3.164–3.729 N•m).

9. Re-install the pull box front cover removed in step 5 (see ArcBlok 1200 Main Breaker Pull Box) and the top horizontal wireway cover removed in step 4.

DANGER

Hazard of Electric Shock, Explosion, or Arc Flash Apply appropriate personal protective equipment (PPE) and follow safe electrical work practices. See NFPA 70E, NOM-029-STPS, CSA Z462, or local equivalent. This equipment must only be installed and serviced by qualified electrical personnel. Turn off all power supplying this equipment before working on or inside equipment. Always use a properly rated voltage sensing device to confirm power is off. Replace all devices, doors, and covers before turning on power to this equipment. Failure to follow these instructions will result in death or serious injury.

The top and bottom horizontal wireways and the vertical wireway are convenient areas to run incoming line, load, and control wires (see Wiring in the Top Horizontal Wireway). Openings between sections permit wire to pass from one section into the next for interwiring.

Wiring in the Top Horizontal Wireway

Control and power wires are routed to each unit via the vertical wireway. When supplied, grommeted wire ports must be opened to route wire to the unit. The Hshaped cut pattern is pre-scored for easy opening. Using a small knife, cut through the center tabs and complete the H-shaped slice. When cutting, be sure not to damage the wires located near the grommet.

Pull-apart control terminals (see Pull-apart Type Terminal Blocks) are mounted on a 35 mm DIN rail located adjacent to the wiring ports toward the front of the unit. Terminate field control wiring on the removable portion of the block.

Pull-apart Type Terminal Blocks

Verify all incoming wires are correctly installed in wire terminals and tightened to required torque values. Torque requirements are found on labels on the main device or on a separate label inside the unit.