46
FIGURE 8.
O
2
Level Alarm Limits
Each profile will have its own set of alarm level values. The alarm value for each succeeding
profile setpoint is interpolated from these inputs.
Rules for alarm notification:
a. The O2 level drops below the absolute value of 0.5% O2 for 30 seconds.
b. The O2 level drops below the low alarm limit for 2 minutes.
c. The O2 levels drops below twice the low alarm level for 30 seconds.
d. The O2 level rises above the high alarm limit for 2 minutes.
e. The O2 level rises above twice the high alarm limit of 30 seconds.
Note: The O2 level alarm timer is reset to 0 when the actual O2 level returns to within the accept-
able zone.
FLUE TEMPERATURE ALARM LIMITS
The PPC4000 provides flue temperature limits for each profile. Available is the option to activate
flue temperature limits as warning. In warning mode, a message will be posted to the display and
alarm relay will be energized.
To use flue temperature alarm the user must enter the low limit flue temperature and high limit flue
temperature. When the burner is firing the flue temperature must remain in the acceptance zone
defined by these two limits as shown in the following chart:
2
3
4
5
6
7
8
9
10
0
10
20
30
40
50
60
70
80
90
100
O
x
y
g
e
n
L
e
v
e
l
Firing Rate
O2
ALM@Hi
O2
Level
O2
ALM@Lo
Lo ALM @ LO
Lo ALM @ HI
Hi ALM @ HI
Hi ALM @ LO
