Freelance controls for a cultures producer's freeze dryers

The challenge

A producer of cultures and flavors runs production freeze dryers. It wanted all of its dryers on one control system that its operators could run from a single station, and it needed a partner to keep that system running and to add dryers later without starting over.

What we did

• Built the original system (2022–23) around ABB Freelance AC 700F controllers, one per dryer, linked over PROFIBUS to a central Freelance operator and engineering station with a 21.5" touch screen:
  • three dryer control systems;
  • panels in Hammond enclosures with ABB molded-case breakers on rotary handles;
  • WEG contactors and motor protectors;
  • solid-state power relays;
  • a 480–208 V transformer;
  • ABB plug-in relays and terminal blocks.
• Installed, programmed and tested the first three freeze dryers on site.
• Maintained and improved it. Our engineer made regular site visits to:
  • fix relay faults and add blower control to one dryer;
  • build trend displays for all systems;
  • reprogram the oil failsafe and blower overload logic after parts changes;
  • add a variable valve to the program and HMI;
  • set up data archiving;
  • replace controller batteries;
  • manage Windows updates on the operator station.
• Extended the system (2026). When the plant added another dryer, we quoted bringing it onto the existing system rather than as a stand-alone unit:
  • a local panel with its own Freelance CPU, 16 digital inputs, 16 digital outputs and 16 analog outputs, isolated 24 VDC relay outputs and a 480/120 V transformer;
  • a NEMA 12 remote panel with PROFIBUS I/O;
  • Freelance licensing and schematics.

  We based the new panels' bills of materials on the original jobs. Most of the program will carry over from the existing dryers. The plant's service contractor marked up HMI changes from the existing screens.

The result

The customer ordered the extension in 2026 and purchasing is under way. Our engineer will handle start-up and on-site signal commissioning. The new dryer will run on the same system as the others, controlled from the existing operator station.

What it shows: a small DCS designed to grow: built once, maintained hands-on, and extended dryer by dryer with reused design and code.

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