MODEL: MD74R

MD74R SPECIFICATIONS

ES-8058 Rev.11 Page 3/3

https://www.m-system.co.jp/

SCHEMATIC CIRCUITRY & CONNECTION DIAGRAM

5

2

6

3

7

8

DISCHARGE

ELEMENT

DISCHARGE

ELEMENT

DIN RAIL ADAPTOR

(for grounding)

4

1

5

2

6

3

7

8

4

1

Series Resistance

Series Resistance

Protected Device

MD74R-FF

SG

SHLD

FG

+

–

*2

LINE

DIN RAIL

DIN RAIL

Grounding

Grounding

MD74R-FG*1

Crossover Wire*5

*3

*3

*4

*4

Crossover Wire*5

(SHLD)

(SHLD)

DISCHARGE

ELEMENT

DISCHARGE

ELEMENT

DIN RAIL ADAPTOR

(for grounding)

Protected Device

SG

SHLD

FG

+

–

LINE

Surge

Side

Surge

Side

Protected

Side

Protected

Side

*1. Choose the MD74R-FG when the shield wire is to be grounded.

*2. When SHLD and SG terminals are not isolated, DO NOT connect the surge protector’s terminal 7 to SHLD.

*3. Oxide film on the surface of an aluminium rail may lower the electric conductivity between this module and the ground.

Use a steel or copper rail.

*4. Be sure to ground the DIN rail. Recommended grounding resistance max. 100 ohms.

*5. Cross-wire from the DIN rail to the metal housing of the protected device to equalize the ground potential.

Ground only the surge protector when the protected device has no grounding terminal.

Specifications are subject to change without notice.