andrews R18 Series Technical Documentation Manual page 20

2.4 Water heater protection
12
Configuration level
Parameter
Analog input 1, 2 and 3; setpoint changeover / shift
Limit comparator; controller type; setpoint 1; locking
Unit address; decimal place / unit signal for out-of-range
Measurement range start analog input 1
Measurement range analog input 1
Measurement range analog input 2
Measurement range analog input 2
Lower setpoint limit
1
Upper setpoint limit
1
Actual value correction, analog input 1
Actual value correction, analog input 2
Actual value correction, analog input 3
Filter time constant for digital filter, analog input 1
These parameters are affected by the setting for the decimal place.
1
The R18 is protected by the following systems:
minimum water flow switch
The water flow switch is installed in the flow manifold and
continuously monitors the minimum water flow. If the water flow
falls below a preset level, the burner is shut down and will go to
lock-out. The water flow switch is factory set and should not be
adjusted.
high limit thermostat (E.C.O.)
In the event of failure of the control thermostat, a preset high
limit thermostat will shut down the burner and go to lockout.
pressure relief valve
The maximum operating pressure of the R18 water heater is 10
bar. The standard safety valve supplied is set to 5 bar. If a
different pressure setting is required this should be specified
and will be set at the factory.
gas burner control
The burner control unit provide control and supervision of the
atmospheric burner. The sequence controller is coupled to the
spindle of the control circuit and to the flame supervision unit
displaying the status, the symbol appearing above the reading
mark indicates the firing sequence or lock-out condition. The
pilot flame is supervised by ionisation current detection.
18IP22B
1
1
1
1
1
1
1
Display Factory setting
C111 9930
C112 5010
C113 0
SCL 0
SCH 100
SCL2 0
SCH2 100
SPL 30
SPH 95
OFF1 0
OFF2 0
OFF3
0
dF1
1