Using Heater Burnout Alarm (Hba); 3-10-1 Hba Detection; 3-10-2 Operating Conditions - Omron E5AZ User Manual

Using Heater Burnout Alarm (HBA)

3-10 Using Heater Burnout Alarm (HBA)

3-10-1 HBA Detection

1,2,3...
To CT terminal
Heater lead

3-10-2 Operating Conditions

• Heater burnout detection works as follows.
1. Connect the current transformer (CT) to terminals 15 and 16, and insert
the heater lead through the CT hole. For specifications, models and exter-
nal dimensions of current transformers that can be used on this controller,
refer to Current Transformer (CT) in Appendix.
2. When current flows through this lead, the current transformer generates
AC current proportional to the current value. The E5AZ/E5EZ measures
this AC current to calculate the current flowing to the heater.
3. If the heater is burned out, the measured current decreases and falls below
the heater burnout detection value. The output is then activated as the
heater burnout alarm.
• Set the heater burnout set value in the "heater burnout detection" param-
eter (adjustment level). To monitor the current value of the current trans-
former, use the "heater current monitor" parameter.
• When you are not using the HBA function, set the "heater burnout"
parameter (advanced function setting level) to "OFF".
• For models with HBA, an OR output is established between the ALM 1
function and the HBA. If the ALM1 function is to be used for HBA only, set
0 as the ALM1 type and do not use ALM1.
• The HBA function can be used when the option unit (E53-AZH) is
mounted on the E5AZ/E5EZ. Be sure to connect the CT to the E5AZ/
E5EZ, and pass the heater lead through the CT hole.
• Turn the heater ON at the same time as or before turning the E5AZ/E5EZ
ON. If the heater is turned ON after turning the E5AZ/E5EZ ON, the
heater burnout alarm will activate.
• Control is continued even if the heater burnout alarm is active. (That is,
the E5AZ/E5EZ attempts to control the heater on which the heater burn-
out alarm has not occurred.)
• The heater burnout alarm is detected when the control output is continu-
ously ON for 190 ms or more.
• The rated current value may sometimes differ slightly from the actual cur-
rent flowing to the heater. Check the current value in an actual operating
state in the "heater current monitor" parameter.
• If there is little difference between the current in a normal state and the
current in the burnout state, detection may become unstable. On a heater
of current 10.0 A or less, maintain a difference of 1.0 A or more. On a
heater of current 10.0 A or more, maintain a difference of 2.5 A or more.
• The HBA function cannot be used when the heater is controlled by a
phase control system or cycle control system. Also, 3-phase heaters can-
not be used.
When heater burnout is detected on a 3-phase heater, use the K2CU-F@@A-@GS
(with gate input terminal). See the respective datasheet for details.
Section 3-10
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