Omron EJ1 User Manual page 122

Detecting Current Errors
Normal Operation
5.8 A
200 V
200 V
5.8 A
200 V
To CT input
5.8 A
When each phase's current is normal, the current is: 5.8 A
Heater Burnout Occurred
Burnout
200 V
200 V
5 A
200 V
To CT input
5 A
To CT input
Current when there is a burnout
b. Star Connection
Example: Using Three 200-VAC, 2-kW Heaters
CT
CT
To CT input
Load: Heater
(example)
200 V
CT
CT
  
1
------ -
  
= 10 A

 3 
= 5 A
With this configuration, the heater burnout detection current is as follows:
Heater burnout detection current =
Load: Heater (example)

1
10 A ------ -


3
5 A
Load: Heater
200 V
(example)
5 A
200 V
To CT input
To CT input

3
 Current when there is a burnout
------ -
2 
5.8
----------------- -
Section 4-5

.


CT
Burnout
CT


= 10 A

= 5 A
+ 5
= 5.4 [A]
2
  
1
3
------ -
  
------ -
 
3  2
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