L2CA / L2CE
5-2-55, Minamitsumori, Nishinari-ku, Osaka 557-0063 JAPAN
Phone: +81(6)6659-8201 Fax:
+81(6)6659-8510 E-mail: info@m-system.co.jp
EM-1987 Rev.2 P. 3 / 3
WIRING INSTRUCTIONS
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SCREW TERMINAL
Torque
: 0.8 N·m
CHECKING
1 ) Terminal wiring: Check that all cables are correctly
connected according to the connection diagram.
2 ) Auxiliary power input voltage: Check voltage across
terminal 9 – 10 with a multimeter.
3 ) Input: Check that the input shows within 0 – 120% of
the rated current.
Be sure to short the secondary side of CT or turn off the
current at its primary side for preventing the CT from
burning when the cables are to be disconnected from
input terminals.
Be sure that the input waveform is sinusoidal to obtain
proper accuracy for model L2CA.
4 ) Output: Check that the load resistance meets the de-
scribed specifications.
ADJUSTMENT PROCEDURE
This unit is calibrated at the factory to meet the ordered
specifications, therefore you usually do not need any cali-
bration.
For matching the signal to a receiving instrument or in case
of regular calibration, adjust the output as explained in the
following.
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HOW TO CALIBRATE THE OUTPUT SIGNAL
Use a signal source and measuring instruments of suffi-
cient accuracy level. Turn the auxiliary power supply on
and warm up for more than 10 minutes.
1 ) ZERO: Apply 0% input and adjust output to 0%.
2 ) SPAN: Apply 100% input and adjust output to 100%.
3 ) Check ZERO adjustment again with 0% input.
4 ) When ZERO value is changed, repeat the above proce-
dure 1) – 3).
5 ) Go through the above procedure for channels 2.
MAINTENANCE
Regular calibration procedure is explained below:
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CALIBRATION
Warm up the unit for at least 10 minutes. Apply 0%, 25%,
50%, 75% and 100% input signal. Check that the output
signal for the respective input signal remains within accu-
racy described in the data sheet. When the output is out of
tolerance, recalibrate the unit according to the “ADJUST-
MENT PROCEDURE” explained earlier.
LIGHTNING SURGE PROTECTION
M-System offers a series of lightning surge protector for
protection against induced lightning surges. Please contact
M-System to choose appropriate models.
