45
•
Temperature control will continue even when the HS alarm turns ON.
•
The SSR failure detection function cannot be used when the heater is being
controlled by phase control or cycle control, or if a 3-phase heater is being
used.
•
The SSR failure detection delay is 10 control periods max.
•
For control points being auto-tuned, the HS alarm will not operate until auto-
tuning is completed.
If the default preset SSR failure current value (0.5 A) is used, obtain the SSR
failure detection current from the following formula.
SSR failure detection current = Normal SSR leakage current
2
•
For example, if the normal SSR leakage current value is 1.0 A, the SSR failure
detection current is as follows:
SSR failure detection current = 1.0
2 = 2.0 A
Heater
1 kW x 3
Control output: OFF
200 VAC
E5ZE-12
SSR: OFF
SSR Failure Detection
Current Value Calculation
SSR Failure Detection
Section 3-11
