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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 4 to 20mA DC signal line 

including both 4-wire and 2-wire transmitters from dam-
age caused by lightning surges

• Absorbs surges only without affecting transmitted sig-

nals.

 

SPECIFICATIONS

BETWEEN LINES

LINE TO 
GND

MGD-24

MGD-65

Discharge voltage

30V min.

70V min.

±500V max.

Max. surge voltage*

40V max.

80V max. ±650V max.

Leakage current

≤5μA

@30V DC

5μA

@70V DC

5μA

@±140V DC

Max. line voltage

30V DC

70V DC

–––

Response time

0.1 μsec.

Discharge current

1000A (8 / 20 μsec.)

Max. load current

100mA

Internal series resist.

approx. 20Ω including return

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 to 90% RH 
in order to ensure adequate life span and operation.

 

DIELECTRIC STRENGTH TEST

• DO NOT perform dielectric strength tests with wires con-

nected to the unit. Otherwise the element will start dis-
charging at discharge voltage, which can cause insulation 
failure. Be sure to return the wires after the test.

 

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

Terminal Cover

Specification Label

LIGHTNING SURGE PROTECTOR FOR

STANDARD SIGNAL LINE & PULSE USE

MODEL

MGD-24/MGD-65

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-8211  Rev.4  P. 1 / 4

INSTRUCTION MANUAL

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