
CHAPTER 4 APPLIED OPERATION
E5AK
4--14
·
Calculate the set value nby the following formule:
Set value =
(current value at normal ope current value at burnout)
2
·
Set the current value at burnout when two or more heaters are con-
nected to the CT to the value at the time that the heater having the small-
est current value burns out (the value when one of the heaters burns out
with all heaters at the same current).
·
Make sure that the following condition is satisfied:
Heater of current 10.0 A or less
Current value at normal operation --- current value at heater burn-
out
≧
1 A
When resultant current is less than 1 A, detection is unstable.
Heater of current 10.0 A or more
Current value at normal operation --- current value at heater burn-
out
≧
2.5 A
When resultant current is less than 2.5 A, detection is unstable.
·
The setting range is 0.1 to 49.9 A. Heater burnout is not detected when
the setting is “0.0” or “50.0”. When the setting is “0.0”, the heater burn-
out alarm is set to “OFF”, and when the setting is “50.0”, the heater
burnout alarm is set to “ON”.
·
Set the total current value at normal heater operation to 50 A or less.
When set to 55.0 A or more, [
] is displayed in the “heater current
monitor” parameter.
Example 1 : when using a 200 VAC, 1 kW heater
Current at normal operation =
1000
200
= 5A (
<
10A)
Current at heater burnout = 0A
Set value =
5+0
2
= 2.5A
Example 2 : when using three 200 VAC, 1 kW heaters
Set value =
Current at normal operation =
1000
200
×
3 = 15A (
≧
10A)
Current at burnout of one heater =
1000
200
×
2 = 10A
15+10
2
= 12.5A
(current at normal operation---current at heater burnout
= 15 --- 10 = 5A (
≧
2.5A)
Symbol
Parameter Name: Mode
Application
Heater current monitor
: Level 1
Heater current value monitor
Heater burnout
: Level 1
Heater burnout detection
Heater burnout latch
: Option
Heater burnout detection alarm latch
J
How to calculate
the heater burn-
out set value
F
Examples of use
15
Control output
17
Heater
1KW
AC200V
CT
E5AK
15
Control output
17
Heater
1KWx3
AC200V
CT
E5AK
Parameters