General and Application Information

The standard QED-6 switchboard enclosure is NEMA Type 1, general purpose. NEMA Type 1 enclosures are dead-front, metal-enclosed structures. All sheet steel parts of the enclosure, inside and out, are painted using an electro-deposition process.

Standard Features:

• Secondary wiring areas

• Removable, steel top plates over conduit entrance

• Hinged front doors with latches

• Circuit breaker or instrument compartment

• Bus compartment

• Cable compartment

• Capability for future expansion

• Two piece removable side and back plates

• 1 1/2-inch high base channels

• Electro-deposition paint process on structural parts

• ANSI #49 paint color

• Customer nameplates for each compartment Available Options:

• Vertical bus barriers

• Strip heaters in circuit breaker, bus, and cable compartments

• Overhead circuit breaker lifting device or floor crane

• Gasketing around doors and between sections

• Filtering of doors and vents

• Lockable hinged rear doors

• Lockable front hinged doors

• 18-inch high pull box

• Bottom plates

• Rodent barriers

QED-6 switchboards are also available in a NEMA Type 3R walk-in enclosure for outdoor installation.

• Front aisle with steel entrance door equipped with panic hardware

• Lockable, hinged rear doors

• Interior fluorescent lighting

• Three-way light switch and convenience outlets near the entrance door

• Strip heaters in circuit breaker and bus compartments

• Overhead circuit breaker lifting device (traveling lifter assembly)

• Removable gasketed steel cover plates over conduit entrance

• One-piece construction for ease of installation

Available Options:

• Exhaust fan ventilation/inside temperature control

• Exterior lighting

• Undercoating

• Inside emergency lighting

• Top entry/exit for incoming and outgoing cables

The control wiring conduit entrance is in both the top and bottom of each section for maximum flexibility.

A removable top plate (4-inch by 5-inch) can be punched easily; up to four individual 3/4-inch control conduits per section.

Two bottom conduit entrances in each circuit breaker compartment permit cables to exit through the bottom of the compartment.

The secondary horizontal wireway (see Standard Features) is directly above each circuit breaker compartment, allowing easy access to secondary terminals.

The vertical wireway is on the right side of the section for quick and easy wiring installation.

Standard Features:

• Control wires in wiring trough above the circuit breaker compartment

• Originates directly from the circuit breaker without the use of an intermediate terminal block for factory and customer wiring

• Snap-in wire tie provisions

• Cage clamp terminal blocks locked directly on the circuit breaker cradle

• Control wiring AWG #14 SISMetering CT wiring AWG #10 SIS

  — Locking pull apart terminal blocks at shipping splits

  — Sleeve type “destination” wire markings

  — Grommeted holes between circuit breaker compartments

Available Options:

• Ring tongue control wiring

• Communications wiring AWG #22 shielded

A circuit breaker lifter bar is used to lift MasterPact NW or MasterPact NT circuit breakers. The size of the circuit breaker determines which lifting bar should be used.

A rail-mounted traveling type circuit breaker lifting device is optionally available with indoor type switchgear. The lifting device is available on enclosures with drip hoods and is capable of lifting MasterPact NW circuit breakers into and out of any compartment. The circuit breaker is raised or lowered by manually cranking the hoisting mechanism. The traveling lifter assembly is supplied with outdoor walk-in enclosures.

In addition, a floor crane can be used with the lifter bar to move a MasterPact circuit breakers into a dedicated work area.

The closing and opening push buttons, the racking handle, and racking mechanism are accessible through the front door cutout, allowing circuit breaker operation and disconnection without opening the door. Optional shutters (see Secondary Wiring System) can be provided, covering live parts when the circuit breaker is removed.

The circuit breaker compartment consists of the circuit breaker cradle, a horizontal secondary terminal block on top of the cradle, and a vertical wireway on the right side of the compartment allowing for top and bottom customer wiring. The cradle structure is a bolted-in assembly that supports the circuit breaker. Integrated into the cradle are the circuit breaker interference interlocks or cell keys.

Cell keys are steel pins on the left side of the cradle. As the circuit breaker is pushed into the compartment, the bracket on the circuit breaker moves past a corresponding bracket on the cradle. If the circuit breaker is not matched correctly for the compartment, the brackets will interfere and the circuit breaker will not go into the compartment. Cell keying is a standard QED-6 switchboard feature.

The racking crank storage hole, racking crank hole, and “Push Stop Release” button are on the bottom of the cradle for MasterPact NW and on the side of the cradle for MasterPact NT. Circuit breaker racking is achieved with the circuit breaker compartment door closed.

When required for metering, optional current transformers are positioned around the stationary main contacts.

QED-6 switchboards have high interrupting ratings to meet the demands of your application. Additionally, the small footprint keeps your electrical room dimensions to a minimum.

Family of MasterPact NW Circuit Breakers (800–5000 A)

MasterPact NT Circuit Breaker (800–1200 A)

The MasterPact NW circuit breaker has fewer parts than conventional circuit beakers while performing the same functions.

The main disconnecting contacts on the rear of the circuit breaker are spring-loaded and self-aligning. These contacts are designed so the pressure at the point of contact on the stationary connectors becomes greater under short circuit conditions.

MasterPact circuit breakers are stored energy devices with a two-step operating mechanism.

Electrically operated circuit breakers have a motor to charge the stored energy mechanism, electric close feature, and electric open feature.

On manually operated circuit breakers, the closing springs are charged by hand. For electrically operated circuit breakers, the springs are charged by an internal electric motor, but can also be manually charged if no control power is available.

Status indicators on the front of the circuit breaker indicate when the closing springs are charged or discharged.

A number of MasterPact circuit breaker accessories are available with QED-6 switchboards. A few of the most common accessories are listed below.

Shutters:

Optional shutters in the cradle automatically block access to the main disconnects when the circuit breaker is in the disconnect, test, or remove position. An optional padlock attachment to lock shutters closed is also available.

Field-installable and Upgradeable Options:

A family of field-installable coils, buttons, motors, connectors, and trip units that include, but are not limited to:

Trip units with or without PowerLogic monitoring capabilities (see MicroLogic<span><span><span style="font-family: Arial; ">™</span></span></span> Trip Units)

• Opening and closing coils (MX, XF)

• Shunt trip unit (MX)

• Undervoltage release (MN)

• Spring charging motor (MCH)

• Sensor plug

• Auxiliary contacts

Additional Accessories Available:

For smaller loads, the PowerPact circuit breaker is also individually mounted for added isolation. The unique plug-in or drawout designs allow for quick and easy circuit breaker changes without the requirement of disturbing other branch circuit breakers.

Additional Accessories Available:

The table below lists the standard and optional trip unit features for MicroLogic Type A (Ammeter), Type P (Power Metering), and Type H (Harmonics) trip units for use in QED-6 switchboards.

For additional information on trip curves, please contact your local Square D™ sales office.

In addition to its metering capabilities, the MicroLogic trip unit system is available with optional status inputs and relay outputs for monitoring discrete contacts and remote control of devices by way of the optional data communications channel.

MicroLogic trip unit metering functions include:

• Amperes and volts

• Frequency

• Power

• Power demand

• Energy

• Energy demand

• Power factor

• Power quality measurements

• Communications

• Fault waveform capture

• Waveform capture

• Data logging

• Programmable contacts

MicroLogic trip unit relaying functions include:

• Current unbalance

• Over/under voltage

• Over/under frequency

• Voltage unbalance

• Phase loss

• Phase sequence

• Reverse power

MasterPact circuit breaker maintenance information:

• Thermal imaging

• Contact wear indicator

• Temperature indication

The PowerLogic™, monitoring system, as well as Transparent Ready™ Web Enabled (TRE) equipment, is available, as an option, with QED-6 Switchboards.

The PowerLogic power monitoring and control systems, and (TRE) systems use a high-performance ethernet backbone with Modbus™ communications. Information about the switchgear and its components is passed to and from a local or remote computer system using PowerLogic Modbus data communications.

PowerLogic system components and additional features are listed below.

PowerLogic circuit monitors and, power meters provide highly accurate meter readings along with disturbance monitoring, analog and digital I/O, onboard logging, and more. Circuit monitors and power meters can be mounted on QED-6 switchboards, auxiliary instrument compartments, and auxiliary sections.