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96
Detecting Current Errors
Section 4-5
2.
Three-phase Heaters
a.
Delta Connection
Example: Using Three 200-VAC, 2-kW Heaters
When each phase's current is normal, the current is:
17.3 A (
≅
×
10 A).
The heater burnout current when there is a burnout at the load line is as fol-
lows:
Heater burnout detection current =
≅
16.15 [A]
The heater burnout current when there is a burnout at the load is as follows:
Heater burnout detection current =
≅
13.65 [A]
To enable detection in either case, use 16.1 A as the heater burnout detection
current.
Normal Operation
CT
To CT input
To CT input
Load
Load
Load
17.3 A
200 V
200 V
17.3 A
17.3 A
200 V
CT
Load: Heater (example)
3
Heater Burnout Occurred
CT
To CT input
To CT input
Load
Load
Load
200 V
200 V
200 V
15 A
15 A
CT
Burnout
CT
To CT input
To CT input
Load
Load
Load
200 V
200 V
200 V
10 A
CT
Burnout
17.3 A
10 A
Load: Heater
(example)
Load: Heater
(example)
Current when there is a burnout
= 10 A
×
×
= 15 A
3
3
2
-------
Current when there is a burnout
= 10 A
×
×
= 10 A
3
1
3
-------
17.3
15
+
2
------------------------
17.3
10
+
2
------------------------
Summary of Contents for EJ1 EtherCAT
Page 2: ...EJ1 Modular Temperature Controllers User s Manual Revised July 2008 ...
Page 3: ...iv ...
Page 19: ...xx ...
Page 213: ...188 Detailed Description of Services Section 6 4 ...
Page 227: ...202 Detailed Description of Services Section 7 5 ...
Page 303: ...278 Index ...
Page 305: ......