BCU 580 · Edition 11.15
119
18 Legend
Ready for operation
Safety interlocks (limits)
Control element position check
LDS Safety limits (limits during start-up)
Gas valve
Air valve
Air/gas ratio control valve
Pilot burner (burner 1)
Main burner (burner 2)
P
Purge
A
External air valve control
1 Pilot burner flame signal (burner 1)
2 Main burner flame signal (burner 2)
Operating signal, main burner
Fault signal
Start-up signal (BCU)
HT
Input for high temperature operation
PZ
Pressure switch for tightness control (TC)
PZH
Pressure switch for maximum pressure
PZL
Pressure switch for minimum pressure
PDZ
Differential pressure switch
P xx
Input signal depending on parameter xx
M
Actuator with butterfly valve
TC
Tightness test
p
u
/2
Half of the inlet pressure
p
u
Inlet pressure
p
d
Outlet pressure
V
p1
Test volume
GZL
Valve with proof of closure switch
Fan
Three-point step switch
Emergency stop
Input/Output, safety circuit
I
N
Current consumption of sensor/contactor
t
L
Tightness control opening time
t
M
Measurement time during tightness test
t
P
Tightness control test period (= 2 x t
L
+ 2 x t
M
)
t
FS
Flame proving period
t
PN
Post-purge time
t
GV
Fan run-up time
t
E
Switch-on delay
t
SA
Safety time on start-up
t
VZ
Pre-ignition time
t
PV
Pre-purge time
t
RF
Controller enable signal delay time