10
LRR 1-50, LRR 1-51 - USA - Installation & Operating Manual -
850702-01
Function
The
LRR 1-50 conductivity controller
, in conjunction with the LRG 1.-.. conductivity electrode,
measures conductivity in conductive fluids. The conductivity electrode used is the LRG 16-4 or
the LRG 16-9 with integrated resistance thermometer for monitoring the fluid temperature.
The
LRR 1-51 conductivity controller
processes the conductivity-dependent current signal from
the LRGT 1.-.. conductivity transmitter. In the conductivity controller, this signal is standardized in
line with the adjusted measuring range and indicated as an actual value on the 7-segment LED
display.
Conductivity controller LRR 1-50:
When the
LRG 1.-.. conductivity electrode
is connected, a
reference measurement is taken and a correction factor CF is set to adapt the conductivity mea-
surement to the specific conditions of the installation.
When a resistance thermometer is connected, the temperature of the water is measured as well
as its conductivity. The conductivity reading is then automatically compensated in the conductiv-
ity controller as a function of the adjusted temperature coefficient
tC
(%/°C). If the temperature
changes, thanks to linear temperature compensation the reading is referenced to 77 °F (25 °C)
over the entire measuring range, and indicated as an actual value on the 7-segment LED display.
The
LRR 1-50, LRR 1-51 conductivity controller
is a
2-position controller,
i.e. the continuous
blowdown valve moves to the OPEN position when the set point is reached. Once the conductivity
has fallen by the set hysteresis, the valve returns to the OPERATING position, provided that the
operating position is enabled. To prevent any loss of water from the boiler, the controller auto-
matically closes the valve when the boiler is shut down. Two flashing LEDs indicate whether the
continuous blowdown valve is opening or closing.
The MAX limit can be varied as desired within the measuring range.
If the MAX limit is reached, the MAX output contact is switched and the MAX LED lights up. It
switches back when the value has fallen below the preset hysteresis.
Faults in the conductivity electrode, conductivity transmitter or electrical connection and setting
errors are indicated as error codes on the 7-segment LED display. In the event of a fault, the MAX
alarm is triggered and the continuous blowdown valve moves into OPERATING position.
If faults occur only in the
LRR 1-50, LRR 1-51 conductivity controller
, the MAX alarm is trig-
gered, the continuous blowdown valve moves into OPERATING position and the system is restart-
ed.
Parameters can be changed or the MAX alarm simulated by turning the rotary knob.
Electrical conductivity is measured in µS/cm. In some countries, ppm (parts per million) is used
as well. Conversion 1 µS/cm = 0.5 ppm. You can set the conductivity controller to the required
unit.
Safety information
The equipment may only be installed, wired and brought into service by qualified and competent
staff.
Fitting and maintenance work may only be performed by authorized staff who have undergone
specific training.
