Siemens 45GG20AG Definite Purpose Contactor User Manual

1. Product Overview

The Siemens 45GG20AG Definite Purpose (DP) Contactor is designed for applications such as HVAC, refrigeration, fans, blowers, and welders. It is a reliable electrical switching device suitable for various commercial, construction, and industrial applications. This 2-pole, 40 Amp contactor operates with a 208-240V AC coil voltage.

Figure 1: Siemens 45GG20AG Definite Purpose Contactor. This image displays the compact unit with its enclosed body and coil, featuring visible screw terminals for electrical connections.

2. Safety Information

WARNING: Electrical shock hazard. Read all instructions carefully before installation or servicing. Failure to follow these instructions may result in serious injury or death.

• Always disconnect power at the main circuit breaker or fuse box before installing, servicing, or removing the contactor.
• Installation and servicing must be performed by qualified and licensed electrical personnel only.
• Ensure all wiring complies with national and local electrical codes.
• Verify the voltage and current ratings of the contactor match the application requirements.
• Do not operate the contactor if it appears damaged.
• Proper grounding is essential to prevent electrical shock.

3. Package Contents

Verify that all items are present in the package:

• 1 x Siemens 45GG20AG Definite Purpose Contactor

4. Key Features

• Configuration: 2-Pole, 40 Amp.
• Coil Voltage: 208-240V 60Hz, 190-220V 50Hz.
• Design: Compact with an enclosed body and coil for quiet operation.
• Mounting: Durable metal back plate for universal mounting.
• Connections: Screw terminals and quick connects for easy electrical connections.
• Contacts: Weld resistant silver Cadmium Oxide contacts.
• Insulation: Class F coil insulation for greater thermal stability.
• Visibility: Visible contact position window.
• Certifications: cRUus, ARI 780 & 790, UL File E14900.

5. Setup and Installation

Before beginning installation, ensure all power to the circuit is disconnected.

5.1 Mounting

1. Select a suitable mounting location that is clean, dry, and free from excessive vibration or heat.
2. Position the contactor on a flat surface. The durable metal back plate allows for universal mounting.
3. Secure the contactor using appropriate screws or fasteners through the mounting holes on the back plate. Ensure it is firmly attached to prevent movement during operation.

5.2 Wiring

The contactor features screw terminals and quick connects for electrical connections.

1. Identify the load terminals (typically marked L1, L2 for line side) and the motor/load terminals (typically marked T1, T2 for load side).
2. Connect the incoming power supply wires to the appropriate line terminals. For 40A versions, box lugs are provided for secure connections.
3. Connect the load (e.g., motor, heater) wires to the corresponding load terminals.
4. Identify the coil terminals (typically marked A1, A2). Connect the control circuit wires to these terminals. Ensure the control voltage matches the contactor's coil voltage (208-240V AC).
5. Tighten all screw terminals to the recommended torque specifications to ensure good electrical contact and prevent loose connections.
6. Verify all wiring connections are correct and secure before restoring power.

6. Operating Instructions

The Siemens 45GG20AG Definite Purpose Contactor operates by energizing its coil, which in turn closes the main power contacts, allowing current to flow to the connected load.

1. Energizing the Coil: When the control circuit applies the rated coil voltage (208-240V AC) to the A1 and A2 terminals, an electromagnetic field is generated.
2. Contact Closure: This electromagnetic field pulls the armature, causing the main power contacts to close. The visible contact position window allows for visual confirmation of contact status.
3. Power to Load: With the contacts closed, power flows from the line terminals (L1, L2) to the load terminals (T1, T2), activating the connected equipment.
4. De-energizing the Coil: When the control voltage is removed from the coil terminals, the electromagnetic field collapses, and springs return the contacts to their open position, disconnecting power to the load.

7. Maintenance and Care

Regular inspection and maintenance can extend the life of your contactor and ensure reliable operation. Always disconnect power before performing any maintenance.

• Visual Inspection: Periodically inspect the contactor for any signs of physical damage, discoloration, or loose connections. Check for excessive dust or debris accumulation.
• Cleaning: If necessary, gently clean the exterior of the contactor with a dry, lint-free cloth. Do not use solvents or abrasive cleaners. Ensure no foreign objects obstruct the moving parts.
• Terminal Tightness: Re-check the tightness of all terminal screws annually to prevent overheating due to loose connections.
• Contact Wear: Observe the contacts through the visible contact position window for signs of excessive wear or pitting. If contacts appear severely worn, the contactor may need replacement.

8. Troubleshooting Guide

This section provides solutions to common issues you might encounter with the contactor.

9. Technical Specifications