Allocating Cts (4-Channel Models Only); Allocating Cts (4-Channel Models Only) V2 - Omron G3ZA - MANUAL 2 User Manual

Allocating CTs (4-channel Models Only)

Note
Note
4-4 Allocating CTs (4-channel Models Only)
(1) When a CT for 0 to 50 A detection is selected, do not set the Current Mon-
itor Selector to 1 (0 to 150 A). The correct current value cannot be detect-
ed if it is set to 1.
(2) When the Current Monitor Selector is set to 2 (0% to 100%), the current
will be displayed as a percentage of the connected CT's range. (For ex-
ample, the current will be 100% for a 50-A current flowing through a CT
for 0 to 50 A detection, as shown in the table above.)
CT for 0 to 150 A Detection (G3ZA-CT150L) Selected
The following table shows representative currents that are detected.
Current Monitor Selector
setting
Minimum monitored value ---
Maximum monitored value ---
(1) When a CT for 0 to 150 A detection is selected, do not set the Current
Monitor Selector to 0 (0 to 50 A). The correct current value cannot be de-
tected if it is set to 0.
(2) When the Current Monitor Selector is set to 2 (0% to 100%), the current
will be displayed as a percentage of the connected CT's range. (For ex-
ample, the current will be 100% for a 150-A current flowing through a CT
for 0 to 150 A detection, as shown in the table above.)
The CT allocation settings specify which currents are measured for the out-
puts of channels 1 to 4. When detecting abnormal current in a single-phase
heater, leave these settings at their default settings.
A heater burnout can be detected in a three-phase heater by allocating two
CTs to one output.
Variable type Parameter name
83/C3 CT1 Allocation
CT2 Allocation
CT3 Allocation
CT4 Allocation
Example Settings for Detection of Three-phase Heater Burnout
The following measurements can be made when the CTs are connected as
shown in the following diagram, CT1 Allocation is set to 1 (channel 1), CT2
Allocation is set to 1 (channel 1), CT3 Allocation is set to 2 (channel 2), and
CT4 Allocation is set to 2 (channel 2).
• The channel 1 outputs are synchronized and the current inputs to CT1
and CT2 are measured.
• The channel 2 outputs are synchronized and the current inputs to CT3
and CT4 are measured.
In this example, all of the CT inputs (4 inputs) are allocated to channels 1 and
2, so a three-phase heater burnout cannot be detected in channels 3 and 4.
0: 0 to 50 A 1: 0 to 150 A
(See note 1.)
0 A
--- 30 A
--- 150 A
165 A
V2
Setting range
0: Disabled
1: Channel 1
2: Channel 2
3: Channel 3
4: Channel 4
Section 4-4
2: 0% to 100%
(See note 2.)
0%
20%
100%
110%
Default
1
2
3
4
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