Mitsubishi FX3U compact PLC keeps F1 team cool

A Formula 1 team's mobile headquarters is a two-storey mobile structure with offices, a catering area, kitchen, bar and lounges for the drivers, as well as plenty of space and comfortable amenities for the team's guests. It is installed on the trailers of four trucks. The air conditioning system for the complete structure has a total output of 190kW. Engineers from Clim Cool Project of Renningen, Germany, chose a Mitsubishi FX3U compact PLC (programmable logic controller) for the main air conditioning system and six Alpha XL micro controllers for the hospitality area systems.

The FX3U communicates via RS 485 serial links with two FR F740 frequency inverter drives that power the ventilation system. These drives are specially designed for maximum power-conservation in pump and fan applications. Up to eight frequency inverters can be connected directly to the system without a fieldbus by using just the RS485 ports.

There was also another important reason to choose the FX3U for the tent's air conditioning system: the only limit on the number of temperature values polled by the program is memory capacity. This is a very important factor for a complex air conditioning system in which a large number of actual and setpoint temperature values have to be compared.

Communications, servo control and high performance

Mitsubishi's FX3U is the third generation of this family of compact PLCs. This controller is fitted with a second adapter bus system and is fully compatible with the existing Melsec FX series. Its particular strengths include communications, servo positioning and performance. It has between 16 and 256 I/Os, program memory for 64,000 steps and a cycle time of just 0.065us.

The Alpha XL micro controller closes the gap between individual components such as relays and time switches and a full PLC. It delivers a high level of functionality, reliability and flexibility at a very reasonable price. The Alpha can process up to 200 function blocks in a single program and each function (time switches, counters, analogue signal processing, clock/calendar function, etc) can be used as often as required by all programs.