MAT2
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-8149 Rev.6 P. 5 / 6
WIRING
■
LEADWIRES
Conductor cross-section area: 5.5 mm
2
minimum for both
the power and the ground lines. However, a local industrial
standard requirement for wiring should take precedence.
■
SOLDERLESS TERMINAL
Applicable ring tongue terminal without insulation sleeve
is as indicated below. Spade tongue terminal must conform
with the ring type size.
In order to ensure IP20 protection (IEC 60529) with a sol-
derless terminal, cover the terminal with a insulation cap
to prevent direct touching by a hand.
F
d : M5 use
B ≤ 13.0 mm
F ≥ 7.0 mm
(F ≥ 8.2 mm for sharing terminals)
T ≤ 1.8 mm
• Applicable Solderless Terminal Size
diameter d
B
T
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TORQUE
Tighten the screw terminals securely. Maximum allowable
torque is of 2.5 N·m.
■
WIRE LENGTH
Keep the wire length to the minimum for both the power
source side and the ground side. An example with single-
phase/two-wire configuration is shown below. The wire
length between the branch point and the ground ( ‘a’ in the
figure) should ideally be less than 0.5 meters. Extra long
wires should not be bundled in coils, but be cut to the mini-
mum required length.
■
PROTECTING LOW-VOLTAGE EQUIPMENT
The MAT2, one-port surge protector, is most suitable to
protect electric devices such as isolation transformers, heat-
ers, electromagnetic contactors, motors. On the other hand,
combination type surge protectors incorporating serial im-
pedance (M-System model examples: MAX, MMA, MAH)
are suitable to protect low-voltage electric devices such as
computers, measuring instruments, transmission devices.
However, when the distance between the distribution
switchboard and the protected device ( ‘b’ in the figure)
is longer than 20 or 30 meters, the reactance of the wires
would function as serial impedance in the combination type
surge protectors.
In this case, the overall protection performance should be
augmented by one-port surge protectors installed inside the
switchboard and next to the protected device, protected de-
vice side cross-wired to the ground.
• Single-Phase/2-wire connection
Protected
Device
Cross-wiring
Distribution Switchboard
Power Source
a
b
G
U
V
PE
(N)
Circuit breaker
2
1
PE
N
3
MAT2
PE
Circuit breaker
2
1
PE
N
3
MAT2
GROUNDING
■
COMMON GROUNDING WITH CROSS-OVER WIRE
Basically a common grounding with cross-wiring between
the MAT2 and the protected device is recommended for ade-
quate protection. Grounding resistance should be less than
100 ohms. If the protected device has no ground terminal,
ground only the MAT2.
The ground point should be close to the MAT2 side as shown
below.
• Single-Phase/2-wire connection
Cross-wiring
PE
Protected
Device
G
U
V
(N)
PE
Circuit breaker
2
1
PE
N
3
MAT2
■
INDEPENDENT GROUNDING
The MAT2 installed inside a distribution switchboard is of-
ten located far from the protected device, thus an independ-
ent grounding is needed. In such cases, keep the grounding
resistance as low as possible (several ohms), or add another
MAT2 for local protection next to the protected device.
ALARM OUTPUT
Optional SPDT relay output is available to alert when the
thermal breaker has separated the discharge element from
the power supply circuit.
If the alarm output should be transmitted remotely via out-
door cables, a surge protector for signal line is required.
Choose a circuit breaker with an alarm output. Configure a
logical addition sequence so that the alarm trips when both
or either of the MAT2 or the breaker alarm trips.
■
RELAY SPECIFICATIONS
Alarm output:
The SPDT relay trips when the thermal
breaker operates and/or power source shut-
down.
Rated load: 250V AC @1A (resistive load)
24V DC @1A (resistive load)
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CONNECTION
Terminal: Tension clamp
Applicable wire size: 0.13 to 1.5 mm
2
Stripped length: 8 mm
CHECKING
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WIRING
• Make sure that wiring is done as instructed in the con-
nection diagram.
• Make sure that the Ground terminal (G) is connected to
the metallic housing of protected equipment.
• Make sure that the Ground terminal (G) is grounded to
earth.
