An End-of-Line Test Stand for Industrial Chillers

The problem

Drake Refrigeration needed to test every industrial chiller at the end of its manufacturing line. Water had to be pumped through each unit at a known, controlled rate while temperatures, pressures, flows, and electrical load were monitored in real time. The results then had to be analyzed, stored, and reported.

Why they came back

Our principal engineer first built a test stand for Drake while working for another firm. Later, Drake reached out directly to commission a complete rewrite. The subject matter was familiar, but the software was written new from the ground up.

What we built

Each chiller is connected to a large insulated water tank, and the test measures how well the running chiller cools that water over time.

• Measurement: up to 10 temperatures, refrigerant pressures, and water flow, read through National Instruments FieldPoint.
• Flow control: software PID loops let operators dial in a flow rate, running up to three loops at once to drive motor-operated valves on three tanks.
• Electrical load: voltage and current are monitored over RS-485, for both single-phase and three-phase units.
• Data and reports: every reading is shown live and saved to a backed-up server, both as data files and in a Microsoft Access database. Reports come from the test application or from custom Access forms.