AUTOFLAME Mk8 MM - Page 162

10 Water Level Control
Mk8 MM Manual Page | 162
# Default Range Description
17
0
WLC: Pump Bypass Operation
The pump bypass (terminal TB) will turn on at the switch point set as a %
of the open range of the valve, and will turn off at an offset from the switch
point, set as the bypass hysteresis, see
expansion options 18 and 19.
However if the pump is turned off, then the pump bypass will also be
turned off. For setting 1, the pump bypass hysteresis is below the switch
point, so the pump bypass will turn off at an offset below the switch point.
For setting 2, the pump bypass hysteresis is above the switch point, so
the pump bypass will turn off at an offset above the switch point.
0
Pump bypass disabled
1
Pump bypass on above switch point
2
Pump bypass on below switch point
18
20
WLC: Pump Bypass Switch Point
The bump bypass switch point is set as a percentage of the valve open
range set in expansion option 16.
5 – 95
5% - 95%
19
5
WLC: Pump Bypass Hysteresis
The pump bypass hysteresis is set at percentage from the pump bypass
switch point set in expansion option 18, and this will below the switch point
for expansion option set to 1 (pump bypass on above switch point) and
above the switch point for expansion option set to 2 (pump bypass on
below switch point).
0
Disabled
1 – 50
1% - 50%
20
0
WLC: Burner Operation on Feedwater Control Fault
For setting 0, the burner will continue to fire if there is a feedwater fault. If
the burner continues to fire and the water level drops below the control
point to first low, an alarm will occur and the burner will stop firing. If a
feedwater servomotor fault occurs, the feedwater pump will continue to
operate. For setting 1 the burner will stop firing if there is a feedwater fault.
0
Burner runs on feedwater control fault
1
Burner stops on feedwater control fault
21
1
WLC: Test Input Operates Shunt Switch
The test input terminal TST can be set for checking the auxiliary alarm
outputs or shunt switch. For setting 0, hold the test input continuously to
cycle through alarm outputs every two seconds. For setting 1, hold the
test input for three seconds to trigger the shunt switch operation, and to
cancel the shunt switch operation, hold the test input for a further three
seconds. See expansion options 22 and 23 for the shunt switch timings.
0
Test input operates alarm outputs test
1
Test input operates shunt switch
22
300
WLC: Shunt Switch – Time to 1
st
Low
When the shunt switch test is activated in expansion option 21, there is
time delay for the water to reach the first low level, allowing the operator to
decrease the water level. This test checks the first low alarm while the
burner continues to operate. If water does not drop to the first low level in
this time period, then MM will revert back to normal run mode and cancel
the shunt switch test.
30 – 600
Seconds