M-system MD7RB-FF User manual

EM-8054 Rev.3 P. 1 / 4
INSTRUCTION MANUAL
LIGHTNING SURGE PROTECTOR FOR
RTD USE (ultra-slim) MODEL MD7RB
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:
Surge protector....................................................................(1)
■MODEL NO.
Confirm Model No. marking on the product to be exactly
what you ordered.
■INSTRUCTION MANUAL
This manual describes necessary points of caution when
you use this product, including installation, connection and
basic maintenance procedures.
When using this product in potentially explosive atmos-
phere or hazardous (classified) location, you have to follow
the safety procedure to install it. Please refer to “SAFE IN-
STALLATION MANUAL” for each type of certification.
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
•High discharge current capacity 20 kA (8 / 20 µs), 1 kA
(10 / 350 µs)
•Ultra-thin 7-mm-wide module can be mounted in high
density
•Excellent protection employing multi-stage SPD circuits
•DIN rail mounting and grounding
•Shield terminal provided
•Does not affect instrumentation signal when combined
with a 3-wire RTD, thanks to the internal high accuracy
series resistors
■SPECIFICATIONS
See Table 1.
Table 1. Specications
MODEL NO. MD7RB-FF MD7RB-FG MD7RB-GF MD7RB-GG
Max. continuous operating voltage (Uc) Line to Line ±3V
Line to Earth ±160V ±7.5V
Line to SHLD ±160V ±7.5V
SHLD to Earth ±160V short ±160V short
Voltage protection level (Up) Line to Line ±25V
@4kV (1.2 / 50 µs) Line to Earth ±800V ±25V
Line to SHLD ±1200V ±800V ±25V
SHLD to Earth ±800V short ±800V short
Leakage current @Uc Line to Line ≤5µA
Other sections ≤5µA
Response time Line to Line ≤4 nsec.
Other sections ≤20 nsec.
Max. discharge current (Imax) 20kA (8 / 20 µs), 1.0kA (10 / 350 µs)
Nominal current (IN) 100mA
Internal series resistance 5.12Ω ±0.3%, ±30 ppm/°C per line
056 222 38 18 [e-mail] www.sentronic.com
SENTRONIC AG

MD7RB
EM-8054 Rev.3 P. 2 / 4
POINTS OF CAUTION
■ENVIRONMENT
•Indoor use.
•When heavy dust or metal particles are present in the
air, install the unit inside proper housing with sufficient
ventilation.
•Do not install the unit where it is subjected to continuous
vibration. Do not subject the unit to physical impact.
•Environmental temperature must be within -25 to +85°C
(-13 to +185°F) with relative humidity within 30 to 90%
RH in order to ensure adequate life span and operation.
•This unit needs a DIN rail as earth grounding bar. Ox-
ide coating of an aluminium rail may lower the electric
conductivity between this module and the ground. Use a
steel or copper rail.
■DIELECTRIC STRENGTH TESTING
•The surge protector starts discharging when 160V or
greater voltage (with floating shield type) or several volts
(with grounding shield type) is applied between lines and
earth. Remove the grounding wire before conducting a
test. Be sure to return the wire after the test.
■AND ....
•We recommend that you keep spare surge protectors 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 Surge Protector for Power
Lines for adequate protection.
COMPONENT IDENTIFICATION
Body
Spring Loader
DIN Rail Mounting
Adaptor (for grounding)
Connection
Diagram
(left side)
Model No.
Indication
INSTALLATION
Mount the unit on a DIN rail. Once installed, do not move
it to another DIN rail.
■MOUNTING THE UNIT ON A DIN RAIL
A)Hang the upper hook of the DIN rail mounting adaptor at
the rear side of unit, on the DIN rail.
B)Push in the lower in keeping pressing the unit to the DIN
rail.
C)DIN rails generally have slight individual variability in
size. If you find it difficult to push in the lower part, go
back to (A) and hang the upper part more deeply onto the
rail and try (B) again.
A
DIN Rail
B
■REMOVING THE UNIT
A)Push down the spring loader utilizing a minus screwdriv-
er.
B)Confirm that it is pulled enough down and pull out the
lower part of the unit.
C)Detach the upper part from the DIN rail.
A
B
Spring Loader
C
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SENTRONIC AG

MD7RB
EM-8054 Rev.3 P. 3 / 4
TERMINAL CONNECTION
Connect the unit as in the diagram below.
Be sure to ground the DIN rail on which the unit is mounted and cross-wire between the rail and FG terminal of the protected
device as shown in Figure 1 in order to equalize the earth potential.
When the unit is connected with a device which has no FG terminal, ground the surge protector only.
■EXTERNAL DIMENSIONS unit: mm (inch)
8
6
5
4
1
2
3
7
4
1
5
2
6
3
8
7
95 (3.74)
7
(.28)
98 (3.86) [1.5 (.06)]
8–M3 EURO
TERMINAL
DIN RAIL
(35 mm wide)
DIN RAIL
ADAPTOR
WIRE INSERTION ANGLE: approx. 20°
57 (2.24)
1.9 (.07)
■Figure 1. GROUNDING
M-RESTER PROTECTED
EQUIPMENT
FG
CROSSOVER WIRE
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.
DIN RAIL ADAPTOR
(for grounding)
DIN RAIL
Grounding
■CAUTION WHEN WIRING
Hold the module steady at the front when you
tighten/loosen screw terminals.
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SENTRONIC AG

MD7RB
EM-8054 Rev.3 P. 4 / 4
■CONNECTION DIAGRAM
M-RESTER
6 3
8
5 2
(SHLD)
DIN RAIL
DIN RAIL
ADAPTOR
Protected Device
FG
Protected Side
Crossover Wire
Surge Side
*1. 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.
*2. Be sure to ground the DIN rail. Recommended grounding resistance ≤100Ω
*3. Cross-wire between the DIN rail and the metal housing of the protected device to equalize the earth potential.
Ground only the surge protector when the protected device has no ground terminal.
*4. Shield wiring method is an example. Proceed according to the system requirements.
*4
*2
*3
7
M-RESTER
RTD
3 6
7
2 5
DIN RAIL
DIN RAIL
ADAPTOR
Surge SideProtected Side
Sheath or
Metal Enclosure
*2
*1*1
8
SG
INPUT
B
4 11 4 A
B
A
B
B
WIRING INSTRUCTIONS
■EURO TERMINAL
Torque: 0.3 N·m
Applicable wire size: 0.2 – 2.5 mm2
Stripped length: 8 mm
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 DIN rail is connected to the metal
enclosure of protected device.
3) Make sure that the surge protector is securely attached
to the DIN rail, and that the rail is grounded to earth.
■DISCHARGE ELEMENT
1) Remove all wiring connected to the surge protector when
you test the module.
2) Check resistance across the terminals indicated in Table
2 on the high resistance range of multimeter and confirm
no conduction. The tester should show 10 MΩ or greater.
3) Confirm conduction across the same terminals with a 500
V DC 1000 MΩ insulation tester. The tester should show
20 MΩ or less.
4) If any of the above tests shows negative, replace the
surge protector.
Table 2.
TERM. MODEL
MD7RB-FF MD7RB-FG MD7RB-GF MD7RB-GG
4 – 5 Yes Yes Yes Ye s
5 – 6 Yes Ye s Yes Ye s
6 – 4 Yes Ye s Yes Ye s
4 – 8 No Yes Yes Yes
5 – 8 No Yes Yes Yes
6 – 8 No Yes Yes Yes
8 – 6 No No Yes Yes
6 – DIN rail Yes Ye s No Yes
8 – DIN rail Yes No Ye s No
Note 1: Apply (+) voltage of the multimeter to the terminal
number indicated on the left side.
Note 2: Polarity does not matter for the insulation tester.
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SENTRONIC AG