69
3. Set Heater Burnout alarm setpoint parameter “Hb”.
With the current sensing transformer connected and the heater in
operation, output energized, change the Heater Burnout Alarm set-
ting from the maximum current setting for the particular current
sensing transformer being used to a lower value. Allow 3 secs. or
more between setting changes. Continue lowering the setting until
the relay is energized and the “HB” status indicator is lit. This is the
maximum current usage of the heater. Using the same procedure,
find the maximum current usage of the heater minus one zone. Set
the setpoint in
between the two
current readings.
In this way, the
operator knows if
one or more zones
fail because the
current sensed
will only be below
the Heater
Burnout Alarm
setting if one or
more zones fail.
Power Supply
Alarm Output
Main
Output
Current Sensing Transformer
Input Sensor
Heater
8
9
5
7
2
1
18
17
4
15
16
+
–
