M-system MDK-LC User manual

BEFORE USE ....
Thank you for choosing M-System. Before use, please check
contents of the package you received as outlined below.
If you have any problems or questions with the product,
please contact M-System’s Sales Office or representatives.
■PACKAGE INCLUDES:
Lightning surge protector...................................................(1)
■MODEL NO.
Confirm Model No. marking on the product to be exactly
what you ordered.
■INSTALLATION / INSTRUCTION MANUAL
This manual describes necessary points of caution when
you use this product, including installation, and basic main-
tenance procedure.
LIMITATION APPLICABLE TO M-RESTER
The M-RESTER will protect electronics equipment from
damage caused by lightning by absorbing most of the
surge voltages.
However, M-RESTER may not be effective against cer-
tain extremely high voltages caused by a direct or almost
direct hit by lightning.
M-RESTER must be installed according to this installa-
tion / instruction manual.
GENERAL
■FUNCTION & FEATURES
• Specifically designed to protect strain gauge transmitters
from lightning surge damage that enters on the wiring
between the strain gauge and the transmitter
• Absorbs surges only without affecting transmitted sig-
nals.
■SPECIFICATIONS
OUTPUT SIDE EXC. SIDE LINE TO GND
Discharge voltage ±0.3V min. 15V min. ±15V min.
Max. surge voltage* ±15V max. 30V max. ±30V max.
Response time ≤5 nsec.
Discharge current
capacity
100A
(8/20 µsec.)
50A
(8/20 µsec.)
50A
(8/20 µsec.)
Leakage current ≤0.2µA
@±0.3V DC
≤0.2µA
@15V DC
≤0.2µA
@±15V DC
Maximum voltage ±0.3V 15V –––
Int. series resist. ≤0.1Ω
*The maximum voltage that could pass through M-RESTER.
Protected equipment must be able to withstand this voltage
for a very short time period.
POINTS OF CAUTION
■ENVIRONMENT
• When heavy dust or metal particles are present in the at-
mosphere, install M-RESTER inside proper housing and
ventilate it.
• Do not install the M-RESTER where it is subjected to
continuous vibration. Do not apply physical impact to the
M-RESTER.
• Environmental temperature must be within -5 to +55°C
(23 to 131°F) and relative humidity within 30 – 90% RH
in order to ensure adequate life span and operation.
■DIELECTRIC STRENGTH TEST
• The unit will start discharging when 15V or greater volt-
age is applied bewteen lines and ground. DO NOT per-
form dielectric strength tests with wires connected to the
unit.
■AND ....
• We recommend that you keep spare M-RESTERs so that
you can replace them when necessary.
• Lightning surge can enter not only through signal lines
but also through power supply lines. We recommend that
you also use the Lightning Arrester for Power Lines for
sufficient protection.
COMPONENT IDENTIFICATION
Body
Specification
Label
Connection
Diagram Label
LIGHTNING SURGE PROTECTOR FOR STRAIN GAUGE USE
MODEL MDK-LC
5-2-55, Minamitsumori, Nishinari-ku, Osaka 557-0063 JAPAN
Phone: [phone] Fax: [phone] E-mail: [e-mail]
EM-8136 Rev.4 P. 1 / 3
INSTRUCTION MANUAL

INSTALLATION
Set the unit so that its DIN rail adapter is at the bottom.
Hung the upper hook at the rear side of unit on the DIN rail
and push in the lower. When removing the unit, push down
the DIN rail adapter utilizing screwdriver (–) and pull.
DIN Rail
35mm wide
Spring Loaded
DIN Rail Adaptor
TERMINAL CONNECTIONS
Connect the unit as in the diagram below.
Be sure to cross-wire between the ground terminal (No. 5 or 10) and that of the protected equipment.
When the M-RESTER is connected with a device which has no ground terminal such like M-System's (See figure to the right),
ground the M-Rester ground terminal (No. 5 or 10) only.
M-RESTER
6
7
1
2
M-RESTER
5
1
2
6
7
8
3 3
8
(PROTECTED EQUIPMENT)
9
44
9
STRAIN GAUGE
XMTR
SHIELDED WIRE
–
+
–
+
G
–
+
OUTPUT
V
U
POWER
EXC.
INPUT
10 5
G
STRAIN GAUGE
EXC.
OUTPUT
■GROUNDING
M-RESTER PROTECTED
EQUIPMENT
G
G
CROSSOVER WIRE
GROUNDING
(100 ohms or less)
A crossover wire between M-RESTER ground and ground or metallic
housing of equipment is required for protection.
If the protected equipment has no ground terminal, ground the
M-RESTER only.
MDK-LC
5-2-55, Minamitsumori, Nishinari-ku, Osaka 557-0063 JAPAN
Phone: [phone] Fax: [phone] E-mail: [e-mail]
EM-8136 Rev.4 P. 2 / 3

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 season. Check whenever
you experience a strong lightning occurrence.
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 (No. 5 or 10) is con-
nected to the metallic housing of protected equipment.
• Make sure that the ground terminal (No. 5 or 10) is
grounded to earth.
■DISCHARGE ELEMENTS
Remove all wiring connected to M-RESTER when you test
the discharge elements.
• Check resistance across the following terminals on the
high resistance range of multimeter (infinite standard).
When measuring across (6) – (7), connect the multimeter
so that positive voltage is applied to (6) terminal.
Terminals (6) – (7), (6) – (10), (7) – (10),
(8) – (10), (9) – (10)
• Check resistance across the terminal (8) – (9) on the high
resistance range of multimeter of 0.3V or less (infinite
standard).
• 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 M-
RESTER.
MDK-LC
5-2-55, Minamitsumori, Nishinari-ku, Osaka 557-0063 JAPAN
Phone: [phone] Fax: [phone] E-mail: [e-mail]
EM-8136 Rev.4 P. 3 / 3