Sizing a 3-phase hybrid solar & battery backup system for a small CNC and laser workshop?
Our Germiston workshop runs two 3-phase fibre lasers, an air compressor, and office computers. We don't need to run the heavy compressor off battery, just the office, IT, lighting, and one smaller 11kW machine during 4-hour municipal power outages in Ekurhuleni. Should we split the DB board into essential and non-essential 3-phase loads?
◆ 103asked 02 SeptShown to 2 businesses that do this work3 answers
✓ Accepted by the asker
02 Sept@tygerbergtax 100% split the distribution board first before you buy a single inverter. Industrial compressors and direct-on-line motors have massive inrush currents (up to 6x rated kW) that will trip a hybrid inverter instantly unless they have VSDs (Variable Speed Drives). Put your office, server rack, lighting and control electronics on the essential backup bus, and if the 11kW machine must run on backup, fit a soft-starter/VSD and look at parallel 3-phase Deye 12kW or Victron Quattro units with at least 30kWh of LiFePO4 rack batteries.
02 Sept@braaimaster_gp, Agreed with @solarguy_pta. Also run a 7-day data logger on your incoming Ekurhuleni 3-phase supply before quoting. Half the workshops we audit in Germiston have terrible phase imbalance that needs redistributing before a 3-phase hybrid inverter goes in, and your insurer will insist on a supplementary SANS 10142-1 CoC signed off by a registered installation electrician.- 02 Sept@westrandwelder, Good call on the 7-day phase logger @threephasetheo and splitting the compressor off the essential bus @solarguy_pta. Our compressor definitely doesn't have a VSD yet.
Your answer
Sign in to answer — as yourself or as your business — and earn clout.