Honeywell BCU 465 - High Temperature Operation

BCU 460, BCU 465 · Edition 11.19 75
Parameters
11.4.4 High temperature operation
Parameter A006
Operation of firing systems above 750°C. The BCU..
D1 and BCU..D2 have a fail-safe input with the func-
tion “High temperature operation”. If firing systems are
operated above 750°C, the system is considered to be
an item of high temperature equipment (see EN746-2).
Here, flame control must be in operation until the fur-
nace wall temperature has exceeded 750°C.
Below 750°C, the flame is monitored by conventional
means (UV sensor or flame rod). In High temperature
mode (>750°C), the flame may be controlled via the
temperature using a safety temperature monitor(STM)
in order to increase the system’s availability. This means
that no incorrect flame signals, e.g. signals from a UV
sensor which interprets reflected UV radiation as extra-
neous signals, may lead to faults.
FCU 500..H1
M
HT
18
HT
HT
BCU 46x..D1
6
22
µC
BCU 46x..D1
6
22
µC
5-8
STM
When the HT input is activated (terminal6), the burner
control unit reverts to High temperature mode, i.e.: the
BCU operates without evaluation of the flame signal.
The safety function of the device’s internal flame con-
trol system is deactivated.
In High temperature mode, the gas valves are opened
and the burners are started as usual without monitor-
ing the presence of a flame.
▼