57
Displaying current detector input (Display only) (Option)
HB (Set value of heater break alarm) (Setting range: 0.0 to 50.0 A) (Option)
[Description]
• When
is set to 0.0, the HB alarm is turned OFF.
• The point at which the alarm is activated can be set in
the parameter of
.
• There are two types of the current transformers (CT)
available: CTL-6-SF type for 1 A to 30 A and CTL-12-
S36-8F type for 20 A to 50 A. Select the suitable type
to the current value of the heater you use.
• How to set the point at which the alarm is actevated:
• Set the output of the PXR to ON continuously to
provide the current to the heater.
• You can monitor the current value of the heater in
the parameter of
. Set the value that is 70 to 80
% of the monitored current value as the final set
value.
• When the number of heaters is “n” (more than two),
set the middle value between the current of “n”
heaters and the current of (“n”-1) heaters.
• When the thyristor (SCR) phase control system is used
to control the heater, the parameters of
and
can-
not be used.
Connect this to the heater.
(Pass it through the
hole of the CT.)
}
Connect these
to the PXR
(no polarity).
• How to connect the current transformer
(CT) for heater break:
• Connection example for the alarm for heater break (PXR4 model)
[Note]
To detect heater current, control output 1 must be kept on
for 0.5 second or longer.
Related parameter:
(page 37)
One turn
Two turns
Power
t
y
!4
!5
o !0 !7 !8
Output of the
heater break
alarm
Control output
+
-
Thermocouple
Heater
Current detector
*CT
Magnetic switch
MG
SW
Electric furnace
Power 100 to 240 V AC 50 / 60 Hz
r
q
PXR4
• In case detection of an error becomes difficult due to in-
sufficient heater capacity, pass the wire through the CT
twice to double the apparent current. This will improve
the sensitivity of the CT. (In this case, set the value that is
twice as much as the original value.)
• When winding the wire around the CT several times, be
sure to wind in the same direction.
www.
.com
1.800.561.8187
