The Contrec 515 CR02 is a reliable single loop process controller designed to measure the volume flow in both main and process lines using analog flow inputs. This versatile device can operate in various modes including local (manual), loop, ratio, or blend mode. It features a user-friendly tuning menu that helps you easily set the Proportional Band and Integral Time Values for the PI control algorithm.
By monitoring the main and process flows, the Contrec 515 CR02 calculates the net volume flow. Operators can view the current ratio and deviation, and if authorized, they can adjust the controlling setpoint directly from the main menu.
The PI control of the process flow is managed through a 4-20mA proportional valve or an industrial dosing pump controller. This system includes integral wind-up protection, and you can program a deadband and output ramp time to minimize wear on valves and actuators, ensuring smooth and bumpless operation.
CALCULATIONS
There are three control modes available where the process flow depends on the main flow: RATIO, BLEND-1, and BLEND-2 modes. The relationships between the flows in these modes are as follows:
Ratio Control Mode:
In this mode, the process flow is a percentage ratio of the main flow (0-400% range).
Pflow
Ratio% = —————- × 100
Mflow
Blend Control Modes:
These modes are designed for blending points before and after the main flowmeter. The process flow is a percentage ratio of the net (combined) flow (0-80% range).
Pflow
Ratio% = —————- × 100
Netflow
