13
Heater burnout alarm (option) (Setting range: 1.0 to 50.0A)
[Description]
• Burnout detect current (parameter
Hb) should be set according to the
type of heater being used.
It is set to 0.0 prior to delivery from
the factory.
• Alarm operating point is set by pa-
rameter Hb.
• Current detector (CT) comes in 2
types, 0 to 30A type (CTL-6-SF) and
20 to 50A type (CTL-12-S36-8F).
It should be selected according to the
heater power source being used.
• Setting of alarm operating point
· Apply current to the heater with
the controller output turned ON.
· Search alarm operating value
while changing the set value of Hb
(when changing the set value, the
next set value should be changed
more than 3 seconds later).
· After operating point is obtained,
use 70 to 80% of the value as the
final set value.
· When N number of heaters are
used, set it in the middle between
the current at N number of heat-
ers and that of N-1 number.
• The heater burnout alarm function
can not be used in case when the
heater is controlled by thyristor
phase angle control system.
• When 3-phase heater is used, heater
burnout can be detected in some
cases. For details, contact our of-
fice.
• Connect of heater burnout detect CT
• Example of connection of heater
burnout alarm (Type: PXZ5, PXZ9)
Wiring to PXZ
(no polarity)
Wiring to heater
(through the hole of CT)
}
• When detection error is large due to
small heater capacity, increase the
apparent current 2 times larger by
putting the wire twice through the
hole to improve the sensitivity of the
detector (in this case, set the current
to a two-fold value).
• When wire through CT is wound
many turns, be sure to wind it from
the same direction.
(Note) In using heater burnout alarm,
set the proportional cycle (TC)
to more than 20 seconds.
Related parameter: TC (Page 11)
1 turn
2 turns
MG
SW
Power source
100 to 240V AC 50/60Hz
Current
detector
＊
CT
Heater
Thermocouple
Magnet switch
Powre source
Control output
Heater burnout
alarm output
Electric furnace
⑧
⑨
⑤
⑦
⑮
⑯
⑰ ⑱ ① ②
+
–
Artisan Technology Group - Quality Instrumentation ... Guaranteed | (888) 88-SOURCE | www.artisantg.com
