Omron G3ZA - MANUAL 2 User Manual page 55

Detecting Heater Burnouts (4-channel Models Only)
Note
1,2,3...
Precautions
38
Setting Ranges Supported in the
The current range and units are determined by the Current Monitor Selector
setting.
Variable type Parameter name
83/C3 Current Monitor Selector
Detection values of 0 to 165 (A or %) max. can be detected, but set the detec-
tion value appropriate for the current range. If the detection value is set above
the current range, errors will not be detected. Refer to 4-3 Selecting the CT (4-
channel Models Only)
V2
Example: Setting the CT1 Heater Burnout Detection Value to 20 A
1. Set the CT1 heater burnout detection value to 20 with a Variable Area
Write command.
2. The current is detected in CT1, and heater burnout is detected with the tim-
ing shown in the diagram on the preceding page.
3. Once the CT1 heater burnout detection value is written, the setting is
saved, and will also be effective the next time that the power is turned ON.
• Turn ON the heater power supply at the same time or before turning ON
the G3ZA power supply. False detection will occur if the heater power
supply is turned ON after the G3ZA power supply.
• The actual current flowing in the heater may not be the same as the
heater's rated current. Check the heater current under actual conditions
using the CT1 to CT4 Heater ON currents.
• Detection will be unstable if there is only a small difference between the
normal current and burnout current. To achieve stable detection, set the
parameters as follows.
• For a Current Monitor Selector setting of 0 (0 to 50 A):
Heaters of less than 10 A: (Normal current - Burnout current) ≥ 2 A
Heaters of 10 A or more: (Normal current - Burnout current) ≥ 3 A
• For a Current Monitor Selector setting of 1 (0 to 150 A):
Heaters of less than 10 A: (Normal current - Burnout current) ≥ 6 A
Heaters of 10 A or more: (Normal current - Burnout current) ≥ 9 A
• For a Current Monitor Selector setting of 2 (0% to 100%):
Heaters of less than 10 A: (Normal current - Burnout current) ≥ 4%
Heaters of 10 A or more: (Normal current - Burnout current) ≥ 6%
If the conditions for stable detection cannot be met, increase the number of
turns of the heater wire through the current transformer and increase the
detection value. The monitored heater ON current value is proportional to the
number of turns.
V2
Models (0 to 165 A, or %)
Setting
0 0 to 55
1 0 to 165
2 0 to 110
on page 33 for details on detection values.
Detection will not be stable if the difference is less
than 2 A.
Detection will not be stable if the difference is less
than 3 A.
Detection will not be stable if the difference is less
than 6 A.
Detection will not be stable if the difference is less
than 9 A.
Detection will not be stable if the difference is less
than 4%.
Detection will not be stable if the difference is less
than 6%.
Section 4-5
Current range Units
A
A
%