Distribution room retrofit for old power setup aims to solve hidden risks left by early stage power distribution construction, and improve power supply reliability, safety level and operation maintenance convenience. Many old distribution rooms face common problems: aging switch equipment, insufficient short circuit withstand capability, disordered cable arrangement, imperfect grounding systems, backward fire proof facilities and narrow operation maintenance space. Partial equipment cannot adapt to increased load demand brought by equipment update in modern production and living scenarios. Retrofit work of old distribution rooms cannot simply carry out large scale blind replacement. It needs to sort out existing system status first, make layered classification reconstruction schemes, and minimize influence on continuous power supply for users during construction periods.

System status survey and overall scheme planning are the first important steps of distribution room retrofit for old power setup. Technical personnel conduct comprehensive site investigation, sort out original circuit diagrams, check operating status of existing switches, busbars, cables and grounding facilities. They test actual short circuit current level of access power grid and measure real time load and future load growth requirement. Based on collected data, reconstruction content is divided into necessary safety improvement items and performance upgrade items. Partial step transformation plans are formulated when conditions permit, so that part of power supply loops can keep working during construction. For old distribution rooms with severely limited building space, compact type new power distribution devices can be considered to solve contradiction between equipment function upgrade and narrow room layout. All retrofit schemes must comply with current power design specifications and safety standards.

Key item reconstruction and construction period safety control guarantee implementation effect of old setup distribution room retrofit. In hardware reconstruction work, replace seriously aged electrical components, upgrade equipment whose short circuit resistance capacity cannot meet present day grid conditions. Rearrange internal cables, realize clear circuit layering, and supplement fire proof blocking at cable penetrating positions. Repair and reconstruct unqualified grounding systems to ensure grounding resistance meets specification requirements. Optimize ventilation, lighting and fire protection configurations inside distribution rooms. During on site construction, implement strict power cut operation management. Isolate construction sections from operating loops with reliable isolation measures. After component replacement completes, carry out necessary electrical tests including insulation test and protection parameter calibration. After whole reconstruction finishes, complete acceptance check according to standard specifications before restoring formal power supply. Scientific planning and standardized construction eliminate safety hazards accumulated in old distribution rooms and lift overall power distribution performance.