MDP-4R
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-8232 Rev.5 P. 3 / 3
TERMINAL CONNECTION
Connect the unit as in the diagram below.
Be sure to cross-wire between the Ground terminal (G) and that of the protected equipment. When the surge protector is con-
nected with a device which has no ground terminal such like M-System’s (See figure below), ground the M-RESTER Ground
terminal (G) only.
Protected Device
MDP-4R
G
C
B
3
2
MDP-4R
G
G
Protected Device
3
2
C
B
A
1
1
G
+
–
+
–
SG
A
LINE
LINE
LINE
LINE
Grounding
≤100
Ω
Grounding
≤100
Ω
*
3
*
1
*
2
*
4
*
4
*
1. Leave Terminal A when the shielded twisted-pair cable is not provided.
*
2. Leave Terminal 1 when the protected device has no SG (Signal Ground) terminal.
*
3. Cross wire to the surge protector’s G terminal when grounding the shield wire.
*
4. Cross-over wire between G terminals of the surge protector and the protected device is required.
Ground only the surge protector if the protected device has no G terminal.
C
B
3
2
MDP-4R
G
+
−
SG
G
A
1
LINE
LINE
*
1
*
2
*
3
3
2
MDP-4R
G
C
B
A
1
Protected Device
G
+
−
*
3
LINE
LINE
SG
■
Example: Protected devices have no SG terminals
■
Example: Each SG terminal is connected with triplex cable
Grounding
≤100
Ω
Grounding
≤100
Ω
Protected Device
*
1. Provide electrical insulation with insulating tape and the like so that the live part is not exposed,
as over voltage may generate on the shield wire.
*
2. Cross wire to the surge protector’s G terminal when grounding the shield wire.
*
3. Cross-over wire between G terminals of the surge protector and the protected device is required.
Ground only the surge protector if the protected device has no G terminal.
■
GROUNDING
M-RESTER
PROTECTED
EQUIPMENT
G
G
CROSSOVER WIRE
GROUNDING
(100 ohms or less)
A crossover wire between M-RESTER ground and the ground or
metallic housing of the equipment is required for protection.
If the protected equipment has no ground terminal, ground the
M-RESTER only.
When the M-RESTER is mounted with DIN Rail Mounting Adapter,
connect the grounding wire to the mounting screw of the M-RESTER.
WIRING INSTRUCTIONS
■
SCREW TERMINAL
Torque: 0.8 N·m
MAINTENANCE
Check surge protectors periodically. Many cases of light-
ning are ignored, and even lightning at a far distance often
causes inductive surges.
We recommend that you check your surge protector 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
1) Make sure that wiring is done as instructed in the con-
nection diagram.
2) Make sure that the Ground terminal (G) is connected to
the metallic housing of protected equipment.
3) Make sure that the Ground terminal (G) is grounded to
earth.
DISCHARGE FUNCTION
The M-RESTER Tester is available for a preliminary check-
ing of the surge protector’s head element.
If any of the above tests shows negative, replace the protec-
tor.
