Output regulator (optional)
Method of operation
Thermostat and control region
The thermostat function switches the burner on or off, as a function of the
temperature and/or pressure. However, this only happens if the burner has
been enabled by the startup signal. The control region is formed by
entering the regulator's set-point and the "Burner on” value (parameter).
The shutdown hysteresis is divided into 3 regions. Generally speaking, the
first section lies below the set-point. The second section lies above the set-
point and bounds the control region, whilst the third section also lies
above the set-point and forms the rundown region.
Thus, the control region can lie asymmetrically around the set-point.
Within the upper and the lower control region, the load regulator operates in
accordance with its set parameters and specifications. If the regulator's
actual value reaches the rundown region, a basic load demand is output to
the compound. If the regulator's set-point exceeds the rundown region, the
regulator is shut down. This takes place either through internal processing
(if the controller is integral, i.e. FMS), or via a relay if the controller is an
external device (VMS). A new startup can take place once the actual value
falls below the switch-on point.
This function can replace the control thermostat required in the system.
Manual control
The output regulator's load specification can be overwritten by setting the
selector switch (2) to "Load” and pressing the Channel 1 switch (4)
upwards. This manual load control is cancelled by pressing the Channel 2
switch downwards.
The shutdown limit is non-operational in manual mode. Hence the manual
mode can be used to test the safety limiter.
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In manual mode, the load regulator's functions such as startup circuit
and control thermostat are switched off
therefore
always monitor the system continuously when using manual control.
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Shutdown limit
Upper control
region
Set-point
Switch-on point
Shutdown
region
Control region
x
LAMTEC
LAMTEC
x
x
x
2
4
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