Nor-Cal SDC15 Controller - Manual (Page 119)

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Chapter 5. DETAILED DESCRIPTION OF EACH FUNCTION
5 - 13 CT (Current Transformer) Input
For CT input, two kinds of current values are provided.
• Current value at output ON.: This current value is used for the heater burnout/over-current event. This current
value is displayed as CT current value.
• Current value at output OFF.: This current value is used for the heater short-circuit event. This current value
cannot be displayed.
When [CT type] is set at “heater burnout detection” (C36 = 0 or C39 = 0), the following operation is performed:
The current value at output ON becomes the CT current value measured when the output specified in [CT output]
is turned ON.
The current value at output OFF becomes the CT current value measured when the output specified in [CT output]
is turned OFF.
When [CT type] is set at “current value measurement” (C36 = 1 or C39 = 1), the following operation is performed:
The current value at output ON becomes the measured CT current value regardless of the output ON/OFF status.
The current value at output OFF is fixed at “0.0A”.
The following shows the functional block diagram of the CT (current transformer) input:
Handling Precautions
The current value at output ON is used when the operation type of the
Internal Event is set at [heater burnout/over-current].
The current value at output OFF is used when the operation type of the
Internal Event is set at [heater short-circuit].
(Setting: Setup C36, C39)
Current value at output ON Current value at output OFF
Current value at output ON.
Current value at
output OFF = 0A
CT type
(Setting: Setup C37, C40)
Monitoring of output status
(ON/OFF)
(Setting: Setup C38, C41)
Wait before measurement
Operation: Heater burnout detection
Output is ON. Output is OFF.
Operation: Current value measurement