Azbil C35 Series User Manual

5-90
Chapter 5. DETAILED DESCRIPTION OF EACH FUNCTION
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 current transformer (CT) input:
(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
,
C4 1
)
Wait before measurement
Operation: Heater burnout detection
Output is ON. Output is OFF.
Operation: Current value measurement
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].
• If a change in current value is 2.5A or less, the CT input suppresses this change
through the filter process.
This prevents the heater burnout event from malfunctioning due to
fluctuation of the current value by variations in heater power voltage.
If the heater current is 2.5A or less, the filter process is activated when this unit
is powered ON or the heater is powered ON. Therefore, it takes 3 to 5s that
the heater current becomes equivalent to the actual current value.
When setting the heater burnout event is set at such low current level, an ON
delay of 3 to 5s is set so that the event is not turned ON accidentally.
5 - 12 Current Transformer (CT) Input

Azbil C35 Series Specifications

General

Brand	Azbil
Model	C35 Series
Category	Controller
Language	English