Allen-Bradley PV CV Heat Flow Controller MasterFlow AH-301 120VAC 1771-RTP4

Allen-Bradley PV CV Heat Flow Controller MasterFlow AH-301 120VAC 1771-RTP4

This is a custom-built Allen-Bradley PV/CV (Process Variable / Control Variable) heat and flow controller system housed in a benchtop granite-finish enclosure. The front panel features two pairs of analog meters — one pair for HEAT (PV and CV) and one pair for FLOW (PV and CV) — along with a central gold rotary selector switch. The enclosure integrates a MasterFlow heat blower, multiple control boards, an Allen-Bradley 1771-series I/O terminal panel, and a drive control board, all factory-wired and self-contained with an AC power cord.

Specifications & What's Included

• System type: PV/CV (Process Variable / Control Variable) heat and flow controller
• Enclosure: Granite-finish benchtop enclosure with gray steel rear panel
• Power: 120 VAC, 60 Hz, 10A (single phase)
• Front panel: 4 analog bar-graph meters (HEAT PV, HEAT CV, FLOW PV, FLOW CV) and central rotary switch
• MasterFlow Heat Blower: Model AH-301 — 300°F max temp, 120 VAC, 60 Hz, 10A (Master Appliance Corp., Racine, WI)
• Control boards: Control Concepts Inc. Model 1601-12-10-T — 120 VAC, 10A (two units)
• Meter/indicator module: Dixson Inc. P/N BE051AXXL4/20MADCV6365
• I/O terminal panel: Allen-Bradley 902-RTP / 1771-RTP4 with DB9 connector and terminal strip
• Drive control board: Drive Control Systems DAC-1020 — 115 VAC (Eden Prairie, MN)
• Main control PCB with multiple regulated outputs (+5V, +18V, -18V) and on-board transformer visible
• AC power cord attached and intact

Applications

PV/CV (Process Variable / Control Variable) systems like this are used in industrial and laboratory process control to monitor and regulate two variables simultaneously — in this case heat (temperature) and flow. The controller reads a process variable (e.g., actual temperature or flow rate from a sensor) and outputs a corresponding control variable signal to drive actuators or heating elements to maintain a set point. This type of system was commonly used in lab research environments, materials testing, chemical processing, and small-scale industrial processes where precise, closed-loop control of heat and fluid flow was required. The Allen-Bradley 1771-RTP4 terminal panel is part of Rockwell Automation's PLC-5 / 1771 I/O platform, a widely deployed industrial automation architecture from the 1980s through 2000s. The MasterFlow AH-301 heat blower is an industrial hot-air blower rated for continuous service up to 300°F, commonly integrated into custom process rigs. The Dixson Inc. meters are analog panel instruments historically used in OEM process control panels for laboratory and industrial measurement display. This system appears to date from the early 1990s based on the Dixson date code (week 30, 1993) and the Control Concepts board generation.