Instruction Bulletin

Safety Information

DANGER

HAZARD OF ELECTRIC SHOCK, EXPLOSION, OR ARC FLASH

• Apply appropriate personal protective equipment (PPE) and follow safe electrical work practices. Refer to NFPA 70E, NOM-029-STPS, or 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 it.
• 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.
• Do not allow petroleum-based paints, solvents, or sprays to contact the nonmetallic parts of this product.
• Before starting a wiring installation or addition, consult a local building or electrical inspector for current National Electrical Code requirements. Local codes vary but are adopted and enforced to promote safe electrical installations. A permit may be needed for electrical work, and some codes may require an inspection.
• This equipment may not be suitable for use in corrosive environments found in agricultural buildings. See NEC 547.

Failure to follow these instructions will result in death or serious injury.

Preparation

1. Determine the wiring or conduit requirements for the main and branch circuits as required by local electrical codes.
2. Select the proper cable clamp or use other approved methods for securing the cable or conduit to the enclosure.
3. Remove the appropriate knockouts required for installation of cable clamps or conduit (Table 1). Refer to Figure 1 for removing knockouts.

Figure 1: Removing Knockouts - This figure illustrates the process of removing knockouts from the enclosure. It shows a knockout being pushed inward with a tool and then detached. The accompanying table lists conduit sizes and their corresponding bolt-on hub numbers, such as 3/4 in. conduit requiring hub B-075.

Enclosure Mounting

Surface Mounting (Indoor and Outdoor)

Secure the enclosure to the wall with appropriate fasteners. Use all pre-cut holes in the back of the enclosure for mounting. See Figure 2.

For Outdoor Use:

• Use the sealing gaskets provided if the mounting knockout locations shown in Figure 2 are used.
• Use either one mounting hole at the top and two at the bottom, or two mounting knockout holes at the top and two at the bottom. See Figure 2.

Surface Mounting Procedure:

Temporarily position the enclosure with the centered tear drop hole. Secure the enclosure to the wall using the four mounting holes.

Figure 2: Surface Mounting - Depicts the enclosure's back with mounting holes and knockouts. It shows options for outdoor mounting (using knockout locations) and indoor mounting (using the center mounting hole).

Flush Mounting (Indoor Enclosure Only)

1. Remove the four small mounting knockouts on the side walls for securing to sixteen-inch stud walls. See Figure 3.
2. Position the enclosure between studs so that the front edge is flush with the finished wall.
3. Secure the enclosure to the studs through the small knockouts. See Figure 3C.

Figure 3: Flush Mounting - Illustrates the flush mounting process, showing the removal of side knockouts (A), the enclosure positioned between studs (B), and securing it to the studs (C).

Main Circuit Breaker or Main Lug Wiring

1. Pull the conductors into the enclosure. Use approved wire clamps, conduit bushings, or other approved methods to secure the conductor to the enclosure and prevent damage to the conductor insulation.
2. Connect the main and neutral wires:
   • Install the main and neutral wires according to the wiring diagram on the load center.
   • Connect the service ground, equipment grounding wire, or both as required by the local electrical code.
   • Torque each connection to the value specified on the load center wiring diagram attached to the enclosure.
3. If required by the local code, install the enclosed green neutral bonding screw through the hole in the neutral bar. Thread the screw into the enclosure and torque to the value specified on the card shipped with the bonding screw.

Branch Circuit Breaker Installation and Removal

WARNING

HAZARD OF PERSONAL INJURY OR EQUIPMENT DAMAGE

This equipment is designed and tested by Schneider Electric™ to performance levels which meet Underwriter's Laboratories® (UL®) standards and Mexican Official Standards (NOM) listing. Use only Square D™ brand circuit breakers and accessories. Failure to follow these instructions can result in death or serious injury.

NOTE: See separate instruction bulletins included with advanced function circuit breakers and accessories for their installation. QO™ type circuit breakers are only acceptable for use on QO plug-on neutral load centers.

Standard and Tandem Branch Circuit Breakers—Installation

NOTE: Install QOT and HOMT tandem-type circuit breakers only in single-phase load centers marked for use with tandem circuit breakers. Refer to the wiring diagram on the load center for the installation location.

1. Determine the wiring or conduit requirements for the branch circuit.
2. Turn OFF (O) the circuit breaker.
3. For QOT CTL tandem only: hold the circuit breaker at a 30–45° angle.
4. Install the wire terminal end of the circuit breaker onto the mounting rail.
5. Rotate the circuit breaker inward until the plug-on jaw fully engages the bus bar connector. Keep the bottom of the circuit breaker's case against the mounting rail. Check the terminal end of the circuit breaker for engagement to the mounting rail.
6. Remove the wire insulation from the branch wire as required. Install the branch wire into the load terminal of the branch circuit breaker.
7. Torque each branch circuit breaker connection to the value specified on the circuit breaker.
8. Torque each neutral and ground connection to the value specified on the load center wiring diagram attached to the enclosure.

Figures 4 & 5: QO Standard and Tandem Circuit Breakers - Illustrate the components of QO circuit breakers, including the wire terminal end, plug-on jaw, bus bar connector, and mounting rail. Note that non-class CTL tandem breakers are shown, and QOT CTL tandem breakers (not shown) cannot be installed on plug-on neutral load centers with metal mounting rails.

Removal

1. Turn OFF (O) the circuit breaker. Remove the wires.
2. To disconnect the plug-on jaw from the connector and mounting rail, lift the plug-on end of the circuit breaker until the circuit breaker jaw disconnects from the bus bar. Continue lifting until the terminal end disengages from the mounting rail. Refer to Figures 4, 5, or 6 depending on circuit breaker type.

Installing the Cover / Trim

1. Remove the cover twistouts. Remove the appropriate twistouts to match the number of circuit breakers being installed. See Figure 8.
2. Attach the Spanish translation label, supplied with the load center, to the inside of the door or cover. See Figure 9.
3. Identify the circuit breakers on the directory label.
4. For service equipment, apply the "Service Disconnect" label(s) near the disconnect handle(s). If the main circuit breaker is installed and the device is used as a branch panel, apply the “Main” label to the trim near the main circuit breaker handle. See Figure 9.
5. Install the trim/cover using the screws provided and torque to 20 lbs-in. (2.3 N•m).
6. For QO outdoor load centers that are 150–225 A single-phase, main lug devices rated for 22,000 RMS symmetrical amperes short circuit systems, use four screws by removing the interior trim support bracket knockout. See Figure 9.
7. Fill any unused circuit breaker opening with the filler plates.

Figures 8 & 9: Remove Twistouts and Label Locations - Figure 8 shows removing pre-scored sections from the cover. Figure 9 illustrates label placement on the enclosure for outdoor and indoor use, including Spanish translation, Main/Service Disconnect, and Directory labels.

Energizing the Load Center

1. Before energizing the load center, turn off the main and all branch circuit breakers.
2. After power is turned on to the load center, turn on the main circuit breaker and then turn on the branch circuit breakers.
3. Rotate the door latch counterclockwise to allow engagement through the door slot (outdoor only).
4. Close the door until secured by the latch.