MAINTENANCE
Check M-RESTER periodically. Many cases of lightning are
ignored, and even lightning at a far distance often causes
inductive surges. We recommend that you check your M-
RESTER about twice a year, before and after the rainy sea-
son. Check whenever you experience a strong lightning oc-
currence. Checking procedure is explained in the following:
■
CHECKING
WIRING
• Make sure that wiring is done as instructed in the con-
nection diagram.
• Make sure that the Ground terminal (3) is connected to
the metallic housing of protected equipment.
• Make sure that the Ground terminal (3) is grounded to
earth.
■
DISCHARGE FUNCTION
Remove all the wires connected to the M-RESTER and test
its discharge capability as follows:
• Apply 150V DC across the terminals (1) – (7) and (2) – (8)
with a resistor of approx. 10kW in serial. Measure leak-
age current. (
≤
1mA standard) Check also that the power
indicator LED is ON.
• Then apply 250V DC and check that discharging occurs.
(
≥
2mA standard)
• Apply 300V DC across the following terminals and meas-
ure leakage current. (
≤
1mA standard)
Terminals (1) – (3), (7) – (3), (2) – (3), (8) – (3)
• Then apply 500V DC and check that discharging occurs.
(
≥
2mA standard)
• If DC power source is not available, check resistance
across the following terminals on the high resistance
range of multimeter (infinite standard).
Terminals (1) – (7), (1) – (3), (7) – (3), (2) – (8), (2) – (3), (8) – (3)
• Check that discharging occurs across the same terminals
with a 500V DC megger. (Indicator of the megger reaches
over-scale.)
• If any of the above tests shows negative, replace the whole
M-RESTER unit.
MGA-100 / MGA-200
5-2-55, Minamitsumori, Nishinari-ku, Osaka 557-0063 JAPAN
Phone: +81(6)6659-8201 Fax: +81(6)6659-8510 E-mail: [email protected]
EM-8271 Rev.4 P. 3 / 3
