SVC Varistors Type
Applications
The Protection of semiconducting elements such as
diodes, thyristors, transistors, IC and relays against
transient Voltages.
Similar protection of many types of measuring
instruments, control machinery and communication
equipment and broadcasting equipment against
inductive lightning and switching surges.
Protection of general purpose electrical equipment,
domestic mechinery and appliances. TV and radios
and similar consumer products against lightning and
switching surges.
Line and groud circuit
Varistor voltage selection table(Z
E
)
Power Supply Voltage
100V AC
200V AC
Type
SVC431D -□□A
SVC471D -□□A
SVC751D -□□A to SVC112D -□□A*
SVC182D -□□A**
Notes :
①
When subjected to megger testing(500V DC), the insulation
resistance value can decrease due to the leakage current of
the SVC, To avoid this remove the varistor or use* marked
SVC.
②
When subjected to dielectric strength test(1000V AC).
remove the SVC or use** marked SVC.
Switching Circuit Protection
Protection of relay
(Contact coil)
Protection of
semiconductors
①
Connect the SVC at a position nearer to the equipment than
the overcurrent protection device
“Ⅰ”
(fuse, MCCB) as is
shown in the diagram.
When the SVC is shorted, the overcurrent protection device
“Ⅰ”
operates (trips or blow off the fuse).
②
If the overcurrent protection device
“Ⅰ”
not be installed
can
in
Ⅰ”
“
position, connect a fuse at
“Ⅱ”
position. Select fuse
rated current for the SVC referring to the following table.
SVC
Applicable fuse
rated current(A)
05A
05B
1 to 2
07A
07B
2 to 3
10A
10B
3 to 5
14A
14B
3 to 10
20A
20B
5 to 15
DISC Ceramic Capacitors
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Varistor voltage selection guide
Power Supply Voltage
12V DC
24V DC
100V DC
Type
SVC220D -□□B
SVC390D -□□B
SVC151D -□□A
SVC201D -□□A
100V AC
SVC221D -□□A
SVC241D -□□A
SVC271D -□□A
Notes :
①
The power supply voltage must not exceed the maximum
allowable circuit voltage of the SVC
Power Supply Circuit Protection
Line circuit
Varistor voltage selection table (Z
L
)
Power Supply Voltage
Type
SVC201D -□□A
100V AC
SVC221D -□□A
SVC241D -□□A
SVC271D -□□A*
SVC391D -□□A
200V AC
12V DC
24V DC
Notes :
①
The power supply voltage must not exceed the maximum
allowable circuit voltage.
②
Since independent wiring loads and capacitive loads cause
the voltage build-up at the time of opening or closing the
load, use SVC having a varistor voltage as high as
possible.(*mark)
③
The bold faced portions of the type letters vary.
SVC431D -□□A
SVC471D -□□A*
SVC220D -□□B
SVC390D -□□B
Select varistors taking a note of operating conditions
peculiar to the equipment.
③
When
“Z
2
”SVC
is connected between the equipment and
ground install an ELCB (Earth Leakage Circuit Breaker). If not
possible, connect a fuse or thermal fuse at
“Ⅲ”position.
Installation
①
When operated at location near heating element or
exposed to direct sun light, confirm that the ambient
temparature range.
②
When operated in dusty or dirty locations, or exposed to
corrosive atomospheres, or where metallic powders or salt
can be expected, be sure to mount within a protective
enclosure.
AC/DC
single-phase circuit
AC
three-phase circuit
Molding
When shielding the SVC in a resin molding, take a note of the
materials used and temperature, since they influence the
reliability. For further information please contact SAMWHA
Telecommunication Circuit Protection
②
Pay due attention to the surge energy generated by the
load.
③
Select SVC referring to the pulse lifetime rating.
④
To further reduce the tendency of sparking across the
contacts connect a capacitors parallel with the SVC. This will
also protect the equipment from electromagnetic wave
jamming.
Current, power and energy rating vs, temperature
Application Notes
Varistor voltage selection guied
Power Supply Voltage
12V DC
Type
SVC180D -□□B
SVC220D -□□B
SVC820D -□□A
24V AC
Notes :
The varistor SVC has a capacitance value. Take not of this when
applying them to high-frequency signal circuits.
SVC390D -□□B
SVC820D -□□A
Overcurrent protection
When surges exceed the rating for the SVC, short-circuits or
damages can be expected. Take following precautions.
AC/DC
single-phase circuit
AC
three-phase circuit
Electrical Characteristics
Operating ambient temperature
Storage temperature
Voltage temperatur coefficient
Insulation resistance(at500V)
-40℃
to
+85℃
-40℃
to
+125℃
-0.05% ℃
Over 1000MΩ
128
SAMWHA CAPACITOR Co., Ltd.
DISC Ceramic Capacitors
129
SAMWHA [ SAMWHA ELECTRIC ]
