Flowserve LRG 16-40 - Manual (Page 6)

6
Explanatory Notes
– continued –
Function
– continued –
n
Temperature compensation NORM: The conductivity/temperature curves of normally used
conditioning agents are stored in the electrode and can be selected.
The standard curve temperature compensation is suitable for boilers operating with variable pressure,
which means that the boiler does not have a fixed working pressure (e.g. low load 0 bar, full load
5 bar). The standard curves of feedwater conditioning agents with different basic conductivities com-
pensate for the influence of the temperature on readings within the operating range.
n
Temperature compensation LINEAR: A fixed temperature coefficient (Tk) is used to correct the
measured conductivity value linearly.
The gradient (default setting: . % / °C) is normally used for steam boilers operating with constant
pressure. The conductivity is ascertained at an ambient temperature of 5°C. The cell constant can
be modified in order to calibrate the value measured by the electrode. The gradient can be verified at
operating pressure with the aid of a calibrated conductivity meter.
At regular intervals the conductivity electrode LRG x-40 sends a data telegram via CAN-bus to the
controller with the following information:
n
Measured conductivity value, referred to 5°C as actual value (X),
n
Measuring range / adaptation of actual value output,
n
Alarm: self-monitoring of electrode supply cables,
n
Alarm: temperature sensor defective,
n
Alarm: excessively high temperature in terminal box.
A short circuit in the cables leading to the measuring electrode, the measuring tube and the resistance
thermometer or the interruption of the data transmission via CAN bus will be indicated by a malfunc-
tion message.
A sensor monitors the temperature in the terminal box and indicates a malfunction if the limit value is
exceeded.
System components
Design
LRG 1x-40
Screwed ", ISO 8-. Fig. 3, Fig. 4
LRR 1-40
Digital switching controller for conductivity electrode LRG x-40
Functions: Conductivity limiter, continuous blowdown controller
Data exchange via CAN bus to ISO 898 using CANopen protocol
URB 1, URB 2
Operating & display unit
Functions: Parameterization, indication via LCD display
Data exchange via CAN bus to ISO 898 using CANopen protocol