53
When all servos are at the desired ignition light-off position, the user presses the NEXT key and the
PPC4000 outputs to the YB110 controller the low fire start signal on terminal D. The YB110 control-
ler will advance into PTFI only if the low fire start purge timer has expired and the low fire start
switch is closed (terminal D). The YB110 controller will automatically sequence through PTFI and
MTFI to AUTO.
After reaching the AUTO stage, the YB110 outputs this state on its terminal 11. Although the flame
safeguard control is in AUTO (igniter off), the PPC4000 remains at P02 to allow adjustment of the
servos. When satisfied with the servo positions the user is allowed to exit commissioning mode with-
out affecting positions P03 and above (pre-commissioned unit) or the user presses the NEXT key to
advance to P03. The following is displayed:. The following is displayed:
Position P03 is defined as the low fire position of the burner and will be displayed as 0% modulation
rate. At this point the user can make adjustments to the servos to achieve the correct fuel/air firing
ratio.
When complete setting the low fire position, the user presses the NEXT key to advance to the next
setpoint, P04.
As a point of information, if this is a newly commissioned unit, hitting the NEXT key at P03 moves
the display to indicate P04 but with the same servo positions as P03.
At each subsequent setpoint position, the user will most likely increase each servo position in order
to increase the firing rate of the burner. However, there are instances, although rare, where a particu-
lar servo position may need to be less than or equal to the previous or successive point. This is non-
monotonic.
Note: Since it is easily assumed the first 'guess' at the ignition positions will not
provide a satisfactory light-off, it would be suggested to place the YB110 in the
CHECK position during PTFI and MTFI to allow adjustment of the above servo
positions to get the optimum light-off firing condition. To adjust the servos, the
aforementioned procedure is used. The SAVE key retains the data.
C
O
M
M
I
S
S
I
O
N
I
N
G
p
0
3
>
A
I
R
(
1
)
7
.
5
°
<
G
A
S
(
3
)
5
.
4
°
C
O
M
M
I
S
S
I
O
N
I
N
G
p
0
3
>
A
I
R
(
1
)
8
.
2
°
<
G
A
S
(
3
)
6
.
3
°
C
O
M
M
I
S
S
I
O
N
I
N
G
p
0
4
>
A
I
R
(
1
)
8
.
2
°
<
G
A
S
(
3
)
6
.
3
°
At any point during the commissioning process it may be necessary to check the state of
other parameters in the system. For example, if the measured value begins to approach
the cut off point, the boiler will shut down and interfere with the commissioning pro-
cess. To view these parameters press the INFO key and bring up a list of system param-
eters with their respective values. Pressing the INFO key again will take you right back
to the commissioning process.
