User Manual

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Using HBA and HS Alarms Section 3-10
• If there is little difference between the current in normal and abnormal
states, detection may become unstable. To stabilize detection, set a cur-
rent value difference of at least 1.0 A for heaters of less than 10.0 A, and
at least 2.5 A for heaters of 10.0 A or more. If the heater current is too low,
loop the load line several times through a CT, as shown in the diagram
below. Looping it through twice will double the detection current.
3-10-2 Installing Current Transformers (CT)
• This function can be used with E5@N models that have the HBA and HS
alarm.
For the E5CN, connect the CT in advance to terminals 14 and 15 (CT1),
or 13 and 15 (CT2). For the E5AN/EN, connect the CT in advance to ter-
minals 14 and 15 (CT1) or 15 and 19 (CT2). Then pass the heater power
line through the CT's hole.
For specifications, models and dimensions of current transformers that
can be used with this Controller, see Appendix A Current Transformer
(CT) page 201.
Single-phase Heaters For single-phase heaters, install the CT in the position shown in the following
diagram.
Three-phase Heaters
(E5@N-@@HH@ 3-phase
Heater Detection Models)
When a 3-phase power supply is used, regardless of the types of connecting
lines, two current transformers (CTs) are required to detect heater burnout
and HS.
1,2,3... 1. Delta connecting lines: Refer to the following diagram for CT installation
positions.
Note Heater voltage fluctuations are not considered here, so be take that
into account when setting the detection current.
2. Star connecting lines: Refer to the following diagram for CT installation po-
sitions.
Note Heater voltage fluctuations are not considered here, so be take that
into account when setting the detection current.
CT
Load line
CT
Load Load (such as a heater)
AC line
Product
To CT input
CT
Load
Load
To CT input
Load
Load (such as a heater)
AC line
AC line
Product
To CT input
Product