SVC Varistors Type
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.
Line and groud circuit
Varistor voltage selection table(Z )
Switching Circuit Protection
Applications
E
Protection of relay
(Contact coil)
Protection of
semiconductors
ꢀThe Protection of semiconducting elements such as
diodes, thyristors, transistors, IC and relays against
transient Voltages.
Power Supply Voltage
Type
When the SVC is shorted, the overcurrent protection device
“Ⅰ”operates (trips or blow off the fuse).
100V AC
SVC431D -□□A
SVC471D -□□A
② If the overcurrent protection device“Ⅰ”can not be installed
in“Ⅰ”position, connect a fuse a“t Ⅱ”position. Select fuse
rated current for the SVC referring to the following table.
ꢀSimilar protection of many types of measuring
instruments, control machinery and communication
equipment and broadcasting equipment against
inductive lightning and switching surges.
200V AC
SVC751D -□□A to SVC112D -□□A*
SVC182D -□□A**
Notes :
05A
05B
07A
07B
10A
10B
14A
14B
20A
20B
SVC
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.
ꢀProtection of general purpose electrical equipment,
domestic mechinery and appliances. TV and radios
and similar consumer products against lightning and
switching surges.
Applicable fuse
rated current(A)
1 to 2
2 to 3
3 to 5
3 to 10
5 to 15
2
③ When“Z ”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.
② When subjected to dielectric strength test(1000V AC).
Varistor voltage selection guide
remove the SVC or use** marked SVC.
Power Supply Voltage
12V DC
Type
Select varistors taking a note of operating conditions
peculiar to the equipment.
Power Supply Circuit Protection
SVC220D -□□B
SVC390D -□□B
SVC151D -□□A
SVC201D -□□A
SVC221D -□□A
SVC241D -□□A
SVC271D -□□A
Installation
24V DC
① When operated at location near heating element or
exposed to direct sun light, confirm that the ambient
temparature range.
Line circuit
Varistor voltage selection table (Z )
100V DC
AC/DC
single-phase circuit
AC
L
three-phase circuit
Power Supply Voltage
Type
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.
100V AC
SVC201D -□□A
SVC221D -□□A
SVC241D -□□A
SVC271D -□□A*
SVC391D -□□A
SVC431D -□□A
SVC471D -□□A*
SVC220D -□□B
SVC390D -□□B
100V AC
Notes :
① The power supply voltage must not exceed the maximum
Molding
allowable circuit voltage of the SVC
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
200V AC
② Pay due attention to the surge energy generated by the
Telecommunication Circuit Protection
load.
12V DC
24V DC
③ Select SVC referring to the pulse lifetime rating.
Current, power and energy rating vs, temperature
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.
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)
Application Notes
Overcurrent protection
Varistor voltage selection guied
③The bold faced portions of the type letters vary.
Power Supply Voltage
Type
When surges exceed the rating for the SVC, short-circuits or
damages can be expected. Take following precautions.
SVC180D -□□B
SVC220D -□□B
SVC820D -□□A
SVC390D -□□B
SVC820D -□□A
12V DC
AC/DC
AC
single-phase circuit
three-phase circuit
Electrical Characteristics
24V AC
Operating ambient temperature
Storage temperature
-40℃to +85℃
-40℃to +125℃
-0.05% ℃
Notes :
Voltage temperatur coefficient
Insulation resistance(at500V)
The varistor SVC has a capacitance value. Take not of this when
applying them to high-frequency signal circuits.
Over 1000MΩ
128
129
SAMWHA CAPACITOR Co., Ltd.
DISC Ceramic Capacitors
SAMWHA [ SAMWHA ELECTRIC ]
