Wiring and pasting in switch cabinet

Proper wiring and pasting in switch cabinets ensures safety, reliability, and compliance with industrial standards.

Mechanical Assembly and Pasting

When assembling a switch cabinet, start with mounting and pasting components such as terminal blocks, relays, and switches. Use standardized sheet metal parts and fasteners like rivets, screws, or setting bolts that comply with DIN/IEC/ISO standards. Remove any sharp edges, burrs, or rough surfaces from ducts and mounting points to prevent insulation damage on wires (DIN EN IEC 60204-1) . Plastic rivets are recommended where possible, and all screwdrivers, including pneumatic or cordless types, should be calibrated for correct torque . Cable ducts and trays should be installed to organize wiring and prevent mechanical stress. Ensure that all devices on doors, such as pushbuttons or indicators, are aligned vertically and perpendicular for uniformity .

Electrical Wiring Practices

For wiring, follow these key guidelines:

• Wire selection: Use the correct wire gauge and insulation thickness according to NFPA 79 or local standards to handle the expected voltage and current safely .
• Connection methods: Modern terminals like WAGO Push-in CAGE CLAMP® allow fast, vibration-proof, and maintenance-free connections for solid and stranded conductors. Lever, push-button, or operating slot variants can be chosen depending on field or factory wiring needs .
• Wire routing: Keep wire lengths reasonable, but allow service loops for future modifications. Store slack under main wireways to avoid interference with other components .
• Safety circuits: Wire safety relays and protective devices in series to ensure that any open circuit stops the machine, maintaining operational safety .

Switch Box Wiring Example

For a basic switchboard controlling a lamp and a socket:

• Connect the phase line to one pole of each SPST switch.
• Connect the other pole of the lamp switch to the lamp, and the socket switch to the socket's phase pole.
• Connect the neutral line commonly to the lamp and socket neutral poles.
• Connect the earth line to the socket's earth pole.
• Additional loads can be added in parallel, ensuring the wiring capacity and component ratings are respected .

Best Practices

• Maintain clear labeling of wires and terminals.
• Avoid sharp bends and excessive tension on cables.
• Ensure all connections are tight and secure to prevent arcing or loosening over time.
• Follow local electrical codes and standards for voltage, current, and protective devices. By combining careful mechanical assembly (pasting and mounting) with organized, standard-compliant wiring, switch cabinets can achieve high reliability, safety, and ease of maintenance.