ABOUT THIS PROJECT
We were contacted via our Web Contact Page by a customer who had issues with a 2003 McQuay ALS 312.3 three system chiller. The chiller utilised efficient technologies for its day of Electronic Expansion Valves, Fan Speed Controllers, Compressor Soft Starters on McQuay’s own Variable Loading Screw Compressor.
We attended site where our now customer stated that the Original Carel PC01 Open Card’s compressor output relays were failing due to the constant Load / Unload Signals being switched to the compressor for capacity control. McQuay could not supply replacement cards or offer any type of controller retrofit. We saw the opportunity to retrofit Carel’s newest PCO5 Controller with the latest Screw Compressor Software for intelligent control.
We received an order so attended site equipped with Carel’s full range of products and retrofitted the 1 chiller with 3 systems. The new controllers uses Solid State Relays for the Load / Unload signals for compressor capacity control so eliminating future wear issues. The new control system was commissioned and handed back to our customer, extending chiller life a further 10 years with payback due to the controllers indigent controlling.