Model DGLBD125/4W — PCclass Infrequent Changeover Switch (Dual Power Design), Mini type What it does Automatically transfers load from main power A to backup power B when main power fails, with transfer time less than 50 ms. When both sources are available, it gives priority to power A for normal supply. Designed for dual power setups in PV systems and inverter applications and for use with city mains and generator backup in typical installations. Key benefits Fast, automatic switchover to minimize downtime and keep critical circuits online. Clear automatic and manual modes for controlled operation and maintenance. Compact 4P mini design supports threephase plus neutral installations while saving panel space. Wide current range for flexible integration: suitable for 10 to 125 A circuits. Main specifications Model: DGLBD125/4W Class: PCclass Infrequent Changeover Switch (Dual Power Design) Type: Mini, 4P Current range: 10 to 125 A Rated voltage: AC 220 V, 50 to 60 Hz Coil voltage operating range: 85% to 110% of rated voltage Core function: automatic transfer to backup power when main fails; priority to main when both present Control circuit: energized immediately after transfer Operation modes Automatic mode: set selector to Auto; device performs automatic transfer and control circuit is energized after transfer. Manual switching is prohibited in Auto mode. Manual mode: before any manual operation, cut off all power and set selector to Manual. After manual operations, selector to Auto. Installation and operational rules 4P models require correct phase sequence on installation. Manual switching under load is prohibited and may damage the control circuit. Always deenergize the unit before performing manual operations or maintenance. Coil voltage must remain within 85% to 110% of rated value to avoid coil overheating or burnout. Maintenance and expected behavior Silver alloy contacts provide reliable conduction; however, inconsistent manual operation speed may accelerate contact degradation. Complete power cutoff is required prior to any manual maintenance or inspection. Regular checks of phase sequence, coil supply voltage, and contact condition are recommended for reliable service. Warnings Insufficient coil voltage can result in coil overheating or burnout. Incorrect phase sequence can cause contact burnout. Manual switching while the switch is carrying load may damage the control circuit or contacts. Typical applications Automatic transfer between city mains and inverter output in residential or small commercial PV installations. Backup generator changeover for critical loads that require short transfer times. Dualsource power management in systems that need reliable, infrequent changeover operation. Additional product notes Customized model, not a smart device. Designed for dual power automatic transfer in PV and inverter systems and similar power environments.