Murray MP1520 15-Amp and 20-Amp Single Pole 120V Circuit Breaker User Manual

1. Introduction

This manual provides essential information for the safe installation, operation, and maintenance of the Murray MP1520 15-Amp and 20-Amp Single Pole 120V Circuit Breaker. Please read these instructions carefully before installation or use to ensure proper function and safety.

2. Safety Information

WARNING: Risk of Electric Shock or Fire.

• Installation and servicing of electrical equipment should only be performed by qualified, licensed electricians.
• Always disconnect power at the main service panel before working on circuit breakers or electrical panels.
• Use only Murray brand circuit breakers in Murray load centers to maintain warranty and ensure compatibility.
• Do not use "used" circuit breakers. The installation of used breakers in a Murray panel will void the warranty and may pose significant safety risks.
• Ensure all wiring connections are secure and meet local electrical codes.

3. Product Overview

The Murray MP1520 is a space-saving, plug-in duplex circuit breaker designed for use in Murray load centers and meter combinations that accept Type MH-T breakers. It combines one 15-Amp and one 20-Amp single-pole 120V circuit breaker into a single unit, occupying one standard panel space.

Figure 1: Murray MP1520 Circuit Breaker. This image shows the front view of the Murray MP1520 duplex circuit breaker, highlighting its compact design and visible amperage ratings.

Figure 2: Murray MP1520 Circuit Breaker. This image provides a side view of the Murray MP1520 circuit breaker, illustrating its plug-in mechanism and terminal connections.

This duplex breaker is ideal for adding new circuits when panel space is limited, providing two independent 1/2" breaker poles in a common unit. It is HACR rated. The internal configuration, as typically shown in technical diagrams for MH-T Duplex breakers, illustrates two independent 1/2" breaker poles, a line connection, and a load connection, all designed to fit within a single panel space.

4. Installation

1. Verify Compatibility: Ensure your load center is rated to accept Type MH-T breakers. Refer to your load center's wiring diagram.
2. Disconnect Power: Turn off the main power supply to the electrical panel at the utility meter or main disconnect. Verify power is off using a voltage tester.
3. Remove Panel Cover: Carefully remove the cover of the electrical panel.
4. Identify Slot: Locate an available 1-inch space on the panel's bus bar. The MP1520 requires one panel space.
5. Install Breaker: Hook the rear of the breaker onto the retaining clip on the panel's bus bar. Press the front of the breaker firmly until it snaps into place on the bus bar.
6. Connect Wiring: Connect the circuit wires to the appropriate terminals on the breaker. The MP1520 has one 15-Amp and one 20-Amp pole. Ensure correct wire gauge for each amperage. Tighten terminal screws to the manufacturer's specified torque.
7. Replace Panel Cover: Once all connections are secure and verified, replace the electrical panel cover.
8. Restore Power: Turn the main power supply back on.

Consult a qualified electrician if you are unsure about any step of the installation process.

5. Operation

The Murray MP1520 circuit breaker protects electrical circuits from overcurrents caused by overloads or short circuits. When an overcurrent condition occurs, the breaker will automatically "trip," interrupting the flow of electricity to the protected circuit.

• ON Position: The breaker handle is fully pushed towards the "ON" position.
• OFF Position: The breaker handle is fully pushed towards the "OFF" position.
• TRIPPED Position: When tripped, the handle will move to an intermediate position, typically between "ON" and "OFF."

To reset a tripped breaker, first move the handle completely to the "OFF" position, then firmly push it to the "ON" position. If the breaker immediately trips again, there is likely a persistent fault in the circuit that needs to be addressed by a qualified electrician.

6. Maintenance

Murray circuit breakers are designed for long-term, reliable operation with minimal maintenance. However, periodic inspection is recommended:

• Visual Inspection: Periodically inspect the circuit breaker and surrounding area for any signs of damage, discoloration, or loose connections.
• Keep Clear: Ensure the electrical panel area remains clear of obstructions and debris to allow for proper ventilation and access.
• Avoid Tampering: Do not attempt to modify or repair the circuit breaker. Replace damaged breakers with new, genuine Murray products.

7. Troubleshooting

If your Murray MP1520 circuit breaker trips frequently, consider the following:

• Overloaded Circuit: The most common cause of tripping is an overloaded circuit. Disconnect some appliances or devices from the circuit and try resetting the breaker.
• Short Circuit: A short circuit can cause immediate tripping. This often indicates a wiring fault or a defective appliance. Unplug all devices from the circuit and try resetting. If it still trips, contact a qualified electrician.
• Ground Fault: While the MP1520 is a standard breaker, ground faults can also cause tripping in some systems.
• Defective Breaker: Although rare, a breaker can become faulty over time. If all other troubleshooting steps fail, the breaker may need replacement.

For persistent issues or if you are uncomfortable performing these checks, contact a qualified electrician.

8. Specifications

9. Warranty and Support

Murray (Siemens) strongly recommends against the use of "used" breakers. The installation of used breakers in a Murray (Siemens) panel will void the warranty on the panel. Murray (Siemens) does not sell used breakers and has not approved any 3rd party sellers to do so.

For technical support or warranty inquiries, please contact Murray customer service through their official website or authorized distributors. Always provide your model number (MP1520) when seeking assistance.