K8AC-H
14
Settings Method
Settings Methods for SSR and ON/OFF Control Heaters
Settings Conditions
Detecting burnouts in just one heater when ten 300-W rated heaters
are connected in parallel to a single-phase 200-V power supply.
The heater is SSR controlled.
Normal Heater Current and Heater Current with One
Heater Element Burnout
Normal current = (300 W
×
10 (heaters))/200 V = 15.0 A
Current with one burnout = (300 W
×
9)/200 V = 13.5 A
Heater burnout alarm set value =
Selecting Heater Element Burnout Detector Models
For the above example, K8AC-H12C
@
-FLK would be selected.
The burnout alarm set value is 14.3 A, so the current input range 2.00
to 22.00 A should be selected.
SSR control is used, so type C should be selected. (Type C is also
selected for ON/OFF control.)
Select the appropriate relay or transistor output specifications,
depending on the application.
K8AC-H Parameter Setting Procedure
(Only the minimum settings are shown here. Refer to pages 16 to
18 for information on how to set parameters.)
1.
Turn ON the power to the K8AC-H. The initial status when power
is turned ON is called Run Mode.
2.
Press the
L
Key for at least 3 s to change from Run Mode to
Adjust Mode (the mode for adjusting burnout alarm set values.)
3.
Set the burnout alarm set values. (AL-1 = CT1 burnout alarm set
value and AL-2 = CT2 burnout alarm set value.)
Set “14.3” to AL-1.
Set the AL-2 burnout alarm set value to “----” so that it will not
detect heater burnout, because this is a single-phase heater.
4.
Change to Run Mode.
Press the
L
Key while in Adjust Mode for at least 1 s to change
to Run Mode.
5.
Check operation.
Test heater burnout detection by burning out one heater.
Also check that there are no malfunctions during temperature
control.
Note:
The default setting for functions including the voltage
fluctuation compensation function, alarm hysteresis, output
ON-delay time, and SSR error detection function is OFF. Turn
ON any of these functions as required.
Settings Method for Cyclic and Phase Control Heaters
Settings Conditions
Detecting burnouts in one heater when five 1,000 W-rated heaters are
connected to each phase of a three-phase delta-connected 200-V
power supply.
A power regulator (phase control) performs heater control.
Normal Heater Current and Heater Current With One
Heater Element Burnout
Example: When One of Five Single-phase Heaters (R-S) Burns
Out
Normal current =
(1,000 W
×
5 (heaters))/200 V = 43.3 A
Current with one burnout = 43.3 A
×
0.91 = 39.4 A
(Refer to
Rate of Change for Currents with Parallel Heaters
Heater burnout alarm set value =
Selecting Heater Element Burnout Detector Models
For the above example, K8AC-H13P
@
-FLK would be selected.
The burnout alarm set value is 41.4 A, so the current input range 20.0
to 200.0 A should be selected.
Phase control is used, so type P should be selected. (Type P is also
selected for cyclic control.)
Select the appropriate relay or transistor output specifications,
depending on the application.
K8AC-H Parameter Settings Procedure
(Only the minimum settings are shown here. Refer to pages 16 to
18 for information on how to set parameters.)
1.
Turn ON the power to the K8AC-H. The initial status when power
is turned ON is called Run Mode.
2.
Press the
L
Key for at least 3 s to change from Run Mode to
Adjust Mode (the mode for adjusting burnout alarm set values.)
3.
Change from Adjust Mode to Set Mode (the default settings mode
for all functions). The password “0169” is required to move to Set
Mode.
4.
Set the heater control method parameter to PH-3 (three-phase
control).
The default setting is PH-1 (single-phase control).
Note:
Set the parameter to CYCL (cyclic control) when using
cyclic control.
5.
Press the
L
Key for at least 1 s to change from Set Mode to Adjust
Mode. Press the
L
Key again for at least 1 s to change from
Adjust Mode to Run Mode.
Note:
The default setting for functions including the voltage
fluctuation compensation function, alarm hysteresis, output
ON-delay time, and SSR error detection function is OFF. Turn
ON any of these functions as required.
Burnout Alarm Set Value Setting Method
Setting Method
•
Wire the K8AC-H, temperature controller (4 to 20 mA current
output type), and power regulator (phase control).
•
Press the
L
Key on the K8AC-H for at least 3 s to change from
Run Mode to Adjust Mode.
•
AL-1 (CT1 burnout alarm set value) will be displayed when the
mode is changed to Adjust Mode. Press the
S
key once when AL-
1 is displayed. Next, press the
U
Key once. The present heater
current value will be displayed on the main display, so note this as
the normal current value. Always have the temperature controller
output at 20.0 mA at this time (See note 1.)
•
Next, disconnect one heater and note the heater current in this
burnout state. Alternatively, use the current when one heater is
burned out (calculated earlier) as the current during malfunction. It
is recommended that the current at an actual burnout is confirmed.
•
Set the K8AC-H burnout alarm set value based on the results. The
burnout alarm set value is set at the mid-point between the normal
current and the current at malfunction, taking errors and variations
in heater capacity into consideration.
•
In this setting example, the set value for AL-2 (CT2 burnout alarm
setting) is the same as the set value for AL-1. (See note 2.)
Note: 1.
The K8AC-H automatically adjusts burnout alarm levels to
compensate based on the temperature controller current
output. The burnout alarm value must be set when the
temperature controller output is at 100% (20 mA), so be
sure to have the temperature controller at 20 mA output.
2.
If the heater capacity is unbalanced, the burnout alarm
values for CT1 and CT2 may not be the same.
(Normal c current at malfunction)
=
15.0 + 13.5
= 14.3 A
2
2
Normal c current at malfunction
=
43.3 + 39.4
=
41.4 A
2
2
3
