BCU 480 · Edition 06.07
47
Selection
6
Safety time
6 .1
Please quote the safety time t
SA
when ordering.
P
N
** P
Z
0,33 x P
N
, P
Zmax
= 350 kW
t
SA
≤
70 kW
> 70 kW*
5 s
3 s
≤
350 kW
> 350 kW**
10 s
10 s
5 s
EN 746-2
0
�
*
* P
Z
0,1 x P
N
, P
Zmax
= 350 kW
t
SA
= 3 s, 5 s or 10 s
P
N
= Rated heat output
P
Z
= Ignition capacity
The safety time of the automatic burner control unit depends
on the burner type, the burner capacity and the respective
application.
Burner with mechanical
combustion air supply
Burner capacity
Calculating the safety time t
6 .1 .1
SA
Natural draught burner with direct ignition
Natural draught burner with pilot burner
kW
Safety time on
start-up t
SA
s
1.00
5
Ignition burner input rating at a level of 10 % of nominal
heat input with a maximum of 350 kW.
