1. Introduction
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104781 - MRF-2 | MRH-2 - V2.4 - 22.07.2020
1.3 Appliance description
Controllers in the MRF-2 | MRH-2 series are universal four-channel PID temperature
controllers used to regulate and control industrial heating and cooling applications.
The four built-in controller components offer complex setting options for optimum
performance of the widest possible range of different control tasks. This means that
two-point and three-point control operations, continuous and pulsed PID control ope-
rations, multi-zonal control, absolute and difference temperature control, and other
complex control tasks up to and including compressor rotation in composite systems
are all possible.
The four autonomous control channels can be combined with external items such
as digital inputs, fault indicators, temperature alarms or button functions. The con-
troller architecture circuit diagram illustrates the full range of combination options
offered by the modular hardware concept.
The MRF-2 | MRH-2 has up to three analogue universal temperature sensor inputs,
one configurable analogue input and up to five digital inputs. Temperature sensor
types KTY, PT-100 (2 or 3 leads) or PT1000 can be connected to it. The analogue
input can be configured to 0 .. 10 V or 4 .. 20 mA.
External plant components such as heating systems, condensing units, control val-
ves, mixing valves, pumps, fans, signal transmitters etc. can be controlled through
up to five relay outputs or a freely configurable analogue output.
The operation and prior setting of the parameters of the MRF-2 | MRH-2 is divided
into four operating levels. Access rights for each level must be determined by the
plant engineering company. The programming level includes, for example, the para-
meters which the end user must be able to adjust during subsequent operation. As
interference with the basic configuration by the end user can result in dangerous
changes to functions, access to the other parameter levels is made more difficult by
the use of codes.
A type RS-485 interface is provided for communication with higher-level systems.
WELBA “KONSOFT”
The configuration software available as an option offers a simple way to set parame-
ters and update the temperature controller. The values measured by the three sen-
sors, the analogue input and the analogue output control signal can be transmitted
to a PC.
These instructions have been compiled with maximum care and attention. However,
their content does not constitute an assurance of product features.
The manufacture cannot be held liable for errors and may at any time make changes
serving technical progress. All rights reserved.
