FCU 500, FCU 505 · Edition 02.17
82
Parameters
12 .3 High temperature operation
The safety temperature limiter (STL) and safety tem-
perature monitor (STM) functions can be adjusted to
the requirements of the system using parameters 20,
22, 23, 24, 25 and 27.
These parameters are only available in conjunction with
the STM function (FCU..H1).
12 .3 .1 Temperature monitoring mode
Parameter 20
Parameter 20 = 0: Off
Temperature monitoring using STL or STM is deacti-
vated.
Parameter 20 = 1: High temperature operation with
STM
Temperature recording to detect high temperature op-
eration (HT operation) of a system without locks, STM
function, automatic reset on return to the permitted
range.
The required double thermocouple must be positioned
at the coldest point in the combustion chamber for
this function so that it can reliably detect whether the
spontaneous ignition temperature (> 750°C) has been
exceeded.
Parameter 20 = 2: Maximum temperature monitoring
using STL
Maximum temperature monitoring with fault lock-out,
reset after the fault has been eliminated by pressing
the button on the front panel or using an externally
connected remote reset device.
The required double thermocouple must be positioned
at the warmest point in the combustion chamber for
this function so that it can reliably detect whether the
maximum permitted temperature has been exceeded.
Parameter 20 = 3: High temperature operation with
STM and maximum temperature monitoring with STL
Combination of maximum temperature monitoring
with STL function and high temperature operation
with STM function. This function may only be used if
the position of the double thermocouple is suitable for
both functions. The double thermocouple must reliably
detect whether the spontaneous ignition temperature
(> 750°C) has been exceeded and also whether the
maximum permitted furnace temperature has been
exceeded.
