Omron E5AN - Page 115

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Using Heater Burnout, Heater Short, and Heater Overcurrent Alarms Section 3-10
V Connecting Lines
Example: Using Two 200-VAC, 2-kW Heaters
The heater burnout current when there is a burnout at the common is as fol-
lows:
Heater burnout detection current = (10 + 5) / 2 ≈ 7.5 [A]
The heater burnout current when there is a burnout at the load is as follows:
Heater burnout detection current = (10 + 0) / 2 ≈ 5 [A]
To enable detection in either case, use 7.5 A as the heater burnout detection
current.
CT
CT
Load
200 V
10 A
10 A→
17.3 A→
200 V
200 V
Load
Normal
Product
To CT input
Product
To CT input
CT
CT
Load
200 V
10 A→
10 A→
200 V
200 V
Load
CT
CT
Load
200 V
5 A→
5 A→
200 V
200 V
Load
Burnout
Product
To CT input
Product
To CT input
Product
To CT input
Product
To CT input
Current when there is a burnout = 10 A × (1/2)
= 5 A
Burnout
Current when there is a burnout = 0 A