BACKGROUND OF THE INVENTION
1. Field of the Invention
[0001] The present invention relates to over voltage protection in low voltage distribution
system, more particularly, to a surge protection device with short-circuit current
protection function.
2. The Related Art
[0002] Because of the factors such as current impacts, frequency voltage fluctuation and
environment temperature change, elements in voltage limiting type SPD, such as piezoresistors
will meet degradation or short-circuit malfunction, which may result in failures such
as overheat, short-circuit or electric shock. Such failures may threaten the surrounding
people or articles, or even the system itself. Therefore, voltage limiting type SPDs
must have degradation or short-circuit protection, that means, voltage limiting type
SPDs shall have releases for preventing thermal breakdown (i.e. providing thermal
protection) or short-circuit malfunctions (i.e. providing short-circuit protection).
When degradation or short-circuit malfunction occurs in a voltage limiting type SPD,
the release may disconnect the SPD from a system, so that the malfunction will not
propagate to the system or cause a fire.
[0003] In existing protection techniques for voltage limiting SPDs, external connected overcurrent
protection elements are usually used as releases for preventing thermal breakdown.
The overcurrent protection elements include breakers, fuses or residual current operated
protective devices (RCD). The external overcurrent protection elements are designed
based on power frequency characteristics and do not have corresponding surge performance
indexes, thus the power frequency performance and the surge performance may not match
in actual applications. Possible results of such mismatch include: the external overcurrent
protection element is not able to bear the surge impact which is matched to the voltage
limiting type SPD; or an overall residual voltage Up value of a combination of the
overcurrent protection element and the SPD is not able to be determined. Such problems
will influence the safety and protection effect of the voltage limiting SPDs.
[0004] The Chinese patent application with an application number
CN200810039516.1, entitled "surge protection device with backup protection" discloses a surge protection
device with backup protection. The surge protection device integrates a short-circuit
protection component and a surge protection component, and overcomes the problem of
high residual voltage brought by using an external overcurrent protection device as
backup protection for a voltage limiting type SPD.
[0005] However, the SPD disclosed in this application still have some drawbacks, for example:
1) the current capacity is small; 2) the short-circuit breaking capacity is low; 3)
a protection to a small multiple overload current is not provided and the protection
range is narrow; 4) the reliability of the short-circuit protection device is not
high; 5) a protection under temporary overvoltage (TOV) caused by a system malfunction
due to large capacity surge current impact is not considered; 6) an overall volume
of the product is large.
SUMMARY
[0006] The present invention discloses a voltage limiting type surge protection device with
short-circuit protection function.
[0007] According to an embodiment of the present invention, an integrated surge protection
device with short-circuit current protection function is disclosed, the surge protection
device comprises a surge protection module and a short-circuit current protection
module. The surge protection module discharges and suppresses a surge current and
voltage and the surge protection module is a plug-in type module. The short-circuit
current protection module has short-circuit protection function and is integrated
in a pedestal. The short-circuit protection module is recoverable and provides short-circuit
protection and plug-in mounting for the surge protection module.
[0008] In an embodiment, the short-circuit protection module comprises: a base and a lid,
a moving contact and a static contact, a lightening sensitive switch, an electromagnetic
mechanism, an elastic connection piece, a baffle plate, a first connection terminal,
a second connection terminal, a first elastic plug and a second elastic plug. The
lid covers the base to form a housing of the pedestal. The static contact includes
a static contact bracket. The lightening sensitive switch is connected to the static
contact and the elastic connection piece. The electromagnetic mechanism includes an
iron yoke and a coil. The elastic connection piece includes an elastic pin, an upper
curved extension part and a lower extension part. The baffle plate is mounted on the
base, the baffle plate and the base forms a self-extinguishing interrupter. The first
connection terminal is connected to an external phase line. The second connection
terminal is connected to an external phase line or a ground line. The first elastic
plug and the second elastic plug is connected to the surge protection module, the
first elastic plug is connected to the first connection terminal and the second elastic
plug is connected to the second connection terminal.
[0009] In an embodiment, the static contact bracket is a U shaped rotary bracket so as to
ensure that the direction of a current flowing through the static contact is consistent
with the direction of a current flowing through the moving contact.
[0010] In an embodiment, a high resistance coil with a resistance larger than 200m Ω is
used to provide a high current limiting capacity. The lightening sensitive switch
is connected in parallel with the high resistance coil and a first end of the lightening
sensitive switch is connected to the static contact bracket.
[0011] In an embodiment, the second end of the lightening sensitive switch is connected
to an elastic pin of the elastic connection piece, the elastic connection piece provides
an elastic force for pressing the lightening sensitive switch. An upper extension
part of the static contact bracket is welded to a first end of the coil at an extension
part of the iron yoke. The upper curved extension part of the elastic connection piece
is welded to a second end of the coil, the lower extension part of the elastic connection
piece is connected to a first elastic plug through a connection piece.
[0012] In an embodiment, ladder shaped gates are disposed on the baffle plate.
[0013] In an embodiment, the moving contact is made of silver tungsten alloy material, the
static contact is made of silver tungsten carbide alloy material.
[0014] In an embodiment, the lightening sensitive switch is a ceramic gas discharge tube
with a nominal DC breakdown voltage higher than 250V.
[0015] In an embodiment, the short-circuit current protection module further comprises a
handle, an operation mechanism, a block plate and a remote alarm device which is optionally
installed.
[0016] In an embodiment, the surge protection module comprises a first plug plate and a
second plug plate, the first plug plate and the second plug plate are plugged with
the first elastic plug and the second elastic plug.
[0017] In an embodiment, an overall width of the product is 27mm or 36mm, a width of the
surge protection module is 9mm or 18mm. The surge protection module has convex edges
with different heights on both sides, the short-circuit current protection module
has grooves with corresponding heights on corresponding surfaces, so that plug operations
in error may be avoided.
[0018] The surge protection device with short-circuit protection function of the present
invention has the following advantages:
- 1) The problem of coordination between a lightening impact current and a power frequency
short-circuit current is solved, and the overall circuit has a high current limiting
capacity. High resistance resistors with positive temperature coefficient, such as
a high resistance coil with a resistance higher than 200mΩ is preferred. The surge
protection device has a strong current limiting capacity, in other words, a strong
short-circuit current protection capacity and a good short-circuit breaking capacity.
- 2) The surge protection device provides protection to a small multiple overload current.
The minimal short-circuit current that can be protected is 10A. The surge protection
device provides protection to a broad range of short-circuit currents and may be applied
to any type of grounding systems.
- 3) A recoverable temporary overvoltage (TOV) tolerance mode is provided, flaming under
traditional TOV failure and tolerance mode is eliminated so as to avoid fire hazards.
The product has a high safety reliability.
- 4) The principle of opening the contact in advance by an electrical force is changed,
actions in error will not occur even under a large capacity lightening impact current,
so the service life of the product is increased.
- 5) The residual voltage Up is controllable, a power frequency current and a surge
current may be converted quickly through dual channels with high flexibility and high
reliability. A frequency sensitive switch not only considers the system over voltage,
but also the operation over voltage. An action in error of the lightening sensitive
switch may be prevented so as to ensure the stability and a high short-circuit breaking
capacity of the product.
- 6) Ablation resistant materials are used for contacts so as to increase the ablation
resistance and anti-electrical wear ability. The contact pressure changes in a small
range even under a large capacity lightening impact current.
- 7) The lightening sensitive switch is connected in a manner of elastic connection,
so that the integrity of the lightening sensitive switch during assembly is guaranteed
and the assembly process is facilitated.
- 8) The attraction of contacts with a same direction of currents and a high resistance
resistor with positive temperature coefficient may reduce the requirements of arc
extinction. Gas channels are enlarged to facilitate the gas exclusion, gas quenching
is utilized such that the volume of the product is smaller.
BRIEF DESCRIPTION OF THE DRAWINGS
[0019] The above and other features, natures, and advantages of the invention will be apparent
by the following description of the embodiments incorporating the drawings, wherein,
Fig. 1 illustrates an overall structural diagram of a surge protection device with
short-circuit current protection function according to an embodiment of the present
invention.
Fig. 2 illustrates a structural diagram of a surge protection module in the surge
protection device with short-circuit current protection function according to an embodiment
of the present invention.
Fig. 3 illustrates a structural diagram of the surge protection module mounting to
a pedestal in the surge protection device with short-circuit current protection function
according to an embodiment of the present invention.
Fig. 4 illustrates a structural diagram of a short-circuit current protection module
in the surge protection device with short-circuit current protection function according
to an embodiment of the present invention.
Fig. 5 illustrates a structural diagram of a baffle plate of the short-circuit current
protection module in the surge protection device with short-circuit current protection
function according to an embodiment of the present invention.
Fig. 6 illustrates a structural diagram of a self-extinguishing interrupter of the
short-circuit current protection module in the surge protection device with short-circuit
current protection function according to an embodiment of the present invention.
DETAILED DESCRIPTION OF EMBODIMENTS
[0020] The present invention discloses a surge protection device with short-circuit protection
function. The surge protection device comprises a surge protection module and a short-circuit
current protection module. The surge protection module discharges and suppresses a
surge current and voltage and the surge protection module is a plug-in type module.
The short-circuit current protection module is integrated in a pedestal and provides
short-circuit protection and plug-in mounting for the surge protection module.
[0021] The short-circuit current protection module comprises: a base and a lid, a moving
contact and a static contact, a lightening sensitive switch, an electromagnetic mechanism,
an elastic connection piece, a baffle plate, a first connection terminal, a second
connection terminal, a first elastic plug and a second elastic plug. The lid covers
the base to form a housing of the pedestal. The static contact includes a static contact
bracket which is a U shaped rotary bracket. The electromagnetic mechanism includes
an iron yoke and a coil, the coil is connected to a high resistance resistor with
a resistance larger than 200mΩ. The electromagnetic mechanism has a strong current
limiting capacity. The lightening sensitive switch is connected to the static contact
and the elastic connection piece. The lightening sensitive switch is connected in
parallel with the coil. A first end of the lightening sensitive switch is connected
to the static contact bracket. A second end of the lightening sensitive switch is
connected to an elastic pin of the elastic connection piece. The elastic connection
piece provides an elastic force for pressing the lightening sensitive switch. An upper
extension part of the static contact bracket is welded to a first end of the coil
at an extension part of the iron yoke. An upper curved extension part of the elastic
connection piece is welded to a second end of the coil. A lower extension part of
the elastic connection piece is connected to the first elastic plug through a connection
piece. The elastic connection piece includes an elastic pin, an upper curved extension
part and a lower extension part. The baffle plate is mounted on the base and ladder
shaped gates are disposed on the baffle plate, so that the baffle plate and the base
form a self-extinguishing interrupter. The first connection terminal is connected
to an external phase line. The second connection terminal is connected to an external
phase line or a ground line. The first elastic plug and the second elastic plug are
connected to the surge protection module. The first elastic plug is connected to the
first connection terminal and the second elastic plug is connected to the second connection
terminal.
[0022] The moving contact is made of silver tungsten alloy material. The static contact
is made of silver tungsten carbide alloy material. The lightening sensitive switch
is a ceramic gas discharge tube with a nominal DC breakdown voltage higher than 250V.
The short-circuit current protection module further includes a handle, an operation
mechanism, a block plate and a remote alarm device which is optionally installed.
[0023] The surge protection module includes a first plug plate and a second plug plate.
The first plug plate and the second plug plate are plugged with the first elastic
plug and the second elastic plug. An overall width of the product is 27mm or 36mm.
A width of the surge protection module is 9mm or 18mm. The surge protection module
has convex edges on both sides and the short-circuit current protection module has
grooves on corresponding surfaces.
[0024] The surge protection device with short-circuit protection function of the present
invention has the following characteristics:
- 1) High resistance resistors with positive temperature coefficient are used to enhance
the short-circuit current protection. A high resistance coil with a resistance higher
than 200mΩ is used so the product has a good short-circuit breaking capacity. The
electromagnetic mechanism may act under a small failure current. The product has a
small minimal instantaneous tripping current value, provides protection to a broad
range of short-circuit currents and may be applied to any type of grounding systems.
- 2) A recoverable temporary overvoltage (TOV) tolerance mode is provided, sparks or
flaming is eliminated.
- 3) The currents flowing through the moving contact and the static contact have a same
direction so that the electrical opening force is reduced. The static contact bracket
has a U shaped rotary structure. The moving contact and a near side of the U shaped
rotary bracket (mounted with the static contact) which is close to the moving contact
will attract each other under the electrical force. When a large current capacity
impact occurs, a response time of moving contact opening will be delayed and an impact
force caused by moving contact opening is small, therefore the operation mechanism
will not trip by mistake. Assisted by the high resistance current limiting and the
design that the contacts may open only when the electromagnetic mechanism acts, the
operation mechanism has a high stability.
- 4) The lightening sensitive switch in a frequency sensitive current conversion switch
is disposed in front of the coil of the electromagnetic mechanism in electrical routine.
In other words, when a surge current intrudes, the surge current is discharged by
the lightening sensitive switch first. The current after discharge then flows through
the coil, thus the surge energy born by the coil and the high resistance resistor
is significantly decreased. The surge bearing capacity of the short-circuit protection
module is increased.
- 5) A self-extinguishing interrupter is formed within the product to replace an original
coupled interrupter, so that the volume of the product is reduced. The self-extinguishing
interrupter is formed as follows: ladder shaped gates are designed on the elements,
after assembly, a semi-hermetic interrupter forms around a position where the moving
contact and the static contact close or open, and the moving contact and the static
contact are completely surrounded by the interrupter. Because of the current limiting
by the high resistance resistor, when the moving contact opens, the arc current is
not so large even under a large failure current, the arc is extinguished at the first
time by gas quenching.
- 6) The moving contact is made of silver tungsten alloy material. The static contact
is made of silver tungsten carbide alloy material.
- 7) The nominal DC breakdown voltage of the lightening sensitive switch is higher than
250V.
- 8) The surge protection module may prevent plug in error.
[0025] Fig. 1 ∼ Fig. 6 illustrate the structural diagrams of an surge protection device
with short-circuit current protection function according to an embodiment of the present
invention. As shown in Fig. 1 ∼ Fig. 6, the surge protection device 100 with short-circuit
current protection function solves the problems brought by using an external overcurrent
protection device as backup protection. The surge protection device 100 with short-circuit
current protection function includes a short-circuit current protection module 101
and a surge protection module 102. The short-circuit current protection module 101
is used to protect the surge protection module 102. The surge protection module 102
is used to discharge and suppress a surge current and voltage. The short-circuit current
protection 101 is integrated in a pedestal for mounting the surge protection module
102. The surge protection module 102 is plug-in type.
[0026] The short-circuit current protection module 101 comprises a base 103, a lid 105,
a moving contact 106, a static contact 107, a lightening sensitive switch 108, an
electromagnetic mechanism 109, a handle 110, an operation mechanism 111, an elastic
connection piece 112, a baffle plate 113, a block plate 114, a first connection terminal
115, a second connection terminal 116, a first elastic plug 117, a second elastic
plug 118 and a remote alarm device 104, the remote alarm device 104 is optionally
installed.
[0027] The lid 105 covers the base 103 to form a housing of the pedestal, that is, the housing
of the surge protection module 102. The static contact 107 includes a static contact
bracket 107a. The static contact bracket 107a is a U shaped rotary bracket using a
U shaped rotary structure so as to ensure that the direction of a current flowing
through the static contact 107 is consistent with the direction of a current flowing
through the moving contact 106. Thus, the moving contact 106 and a near side of the
U shaped rotary bracket (mounted with the static contact) which is close to the moving
contact will attract each other under the electrical force. When a large current capacity
impact occurs, a response time of moving contact opening will be delayed and an impact
force caused by moving contact opening is small, therefore the operation mechanism
111 will not trip by mistake.
[0028] The electromagnetic mechanism 109 includes an iron yoke 109a and a coil 109b. The
coil 109b includes a high resistance resistor and the high resistance resistor performs
current limiting for the coil 109b. The resistance of the high resistance resistor
is larger than 300mΩ. The number of windings of the coil 109b is larger than 100 turns,
which may facilitate the actions of the electromagnetic mechanism under a low fault
current while ensuring a high breaking capacity of the short-circuit protection module.
[0029] The lightening sensitive switch 108 is connected in parallel with the coil 109b of
the electromagnetic mechanism in electrical connection. Further, a first end of the
lightening sensitive switch 108 is connected to the U shaped rotary static contact
bracket 107a of the static contact 107. A second end of the lightening sensitive switch
108 is connected to an elastic pin of the elastic connection piece 112. The elastic
connection piece 112 provides an elastic force for pressing the lightening sensitive
switch 108. The elastic connection piece 112 includes an elastic pin, an upper curved
extension part and a lower extension part. An upper extension part of the U shaped
rotary static contact bracket 107a, on which the static contact 107 is mounted, is
welded to a first end of the coil 109b at an extension part of the iron yoke 109a.
The upper curved extension part of the elastic connection piece 112 is welded to a
second end of the coil 109b. The lower extension part of the elastic connection piece
112 is connected to a first elastic plug 117 through a connection piece 119. In such
a connection type, the lightening sensitive switch is disposed in front of the coil
of the electromagnetic mechanism in electrical routine. More particularly, when a
surge current intrudes, the surge current is discharged by the lightening sensitive
switch first. The current after discharge then flows through the coil, thus the surge
energy born by the coil and the high resistance resistor is significantly decreased.
The surge bearing capacity of the short-circuit protection module is increased.
[0030] The base 103 and the baffle plate 113 are assembled and form a self-extinguishing
interrupter 120 within the product. More particularly, ladder shaped gates are disposed
on the baffle plate 113, when the base 103 and the baffle plate 113 are assembled
tightly, a semi-hermetic interrupter 120 forms around a position where the moving
contact and the static contact close or open. The moving contact and the static contact
are completely surrounded by the interrupter. When the moving contact opens and generates
an arc, the arc is driven by the electrical force and moves downward along one side
of the U shaped rotary bracket, the arc is directly cut by the ladder shaped gates
at the first time and is extinguished.
[0031] The short-circuit current protection module 101 is integrated within the pedestal
for mounting the surge protection module 102. The first connection terminal and the
second connection terminal for connecting external lines are both disposed within
the short-circuit current protection module. The first connection terminal 115 disposed
within the short-circuit current protection module is used to connect an external
phase line, and the second connection terminal 116 disposed within the short-circuit
current protection module is used to connect an external phase line or a ground line.
The first connection terminal 115 disposed within the short-circuit current protection
module is connected to the first elastic plug 117 for mounting the surge protection
module through a series of internal electrical connections, and the second connection
terminal 116 disposed within the short-circuit current protection module is connected
to the second elastic plug 118 for mounting the surge protection module, so that the
short-circuit protection module provides backup protection to the surge protection
module.
[0032] The surge protection module 102 is designed to have a plug-in structure, which may
be replaced easily and quickly. The first plug plate 122 and the second plug plate
123 of the surge protection module 102 are plugged into the corresponding first elastic
plug 117 and the second elastic plug 118 of the short-circuit current protection module
respectively, so that the surge protection module and the short-circuit current protection
module are connected to each other. The surge protection module has convex edges 121
with different heights on both sides, and the short-circuit current protection module
has grooves corresponding to different heights on corresponding mounting surfaces,
therefore the surge protection module may be mounted reliably and plug operations
in error may be avoided.
[0033] The width of the surge protection module 102 is designed to be 9mm or 18mm, which
complies to the international practice and may obtain a strong mounting compatibility.
[0034] The moving contact 106 is made of silver tungsten alloy material. The static contact
107b is made of silver tungsten carbide alloy material. The alloy material may attenuate
the erosion of the moving contact and the static contact caused by the surge energy.
The short-circuit current protection module still works after multiple impacts of
large current capacity, the service life of the short-circuit current protection module
is increased.
[0035] The lightening sensitive switch 108 is a switch element, and is preferred to be a
gas discharge tube, such as a ceramic gas discharge tube. The nominal DC breakdown
voltage of the ceramic gas discharge tube is higher than 250V.
[0036] The surge protection device with short-circuit protection function of the present
invention has the following advantages:
- 1) The problem of coordination between a lightening impact current and a power frequency
short-circuit current is solved, and the overall circuit has a high current limiting
capacity. High resistance resistors with positive temperature coefficient, such as
a high resistance coil with a resistance higher than 200mΩ is preferred. The surge
protection device has a strong current limiting capacity, in other words, a strong
short-circuit current protection capacity and a good short-circuit breaking capacity.
- 2) The surge protection device provides protection to a small multiple overload current.
The minimal short-circuit current that can be protected is 10A. The surge protection
device provides protection to a broad range of short-circuit currents and may be applied
to any type of grounding systems.
- 3) A recoverable temporary overvoltage (TOV) tolerance mode is provided, flaming under
traditional TOV failure and tolerance mode is eliminated so as to avoid fire hazards.
The product has a high safety reliability.
- 4) The principle of opening the contact in advance by an electrical force is changed,
actions in error will not occur even under a large capacity lightening impact current,
so the service life of the product is increased.
- 5) The residual voltage Up is controllable, a power frequency current and a surge
current may be converted quickly through dual channels with high flexibility and high
reliability. A frequency sensitive switch not only considers the system over voltage,
but also the operation over voltage. An action in error of the lightening sensitive
switch may be prevented so as to ensure the stability and a high short-circuit breaking
capacity of the product.
- 6) Ablation resistant materials are used for contacts so as to increase the ablation
resistance and anti-electrical wear ability. The contact pressure changes in a small
range even under a large capacity lightening impact current.
- 7) The lightening sensitive switch is connected in a manner of elastic connection,
so that the integrity of the lightening sensitive switch during assembly is guaranteed
and the assembly process is facilitated.
- 8) The attraction of contacts with a same direction of currents and a high resistance
resistor with positive temperature coefficient may reduce the requirements of arc
extinction. Gas channels are enlarged to facilitate the gas exclusion, gas quenching
is utilized such that the volume of the product is smaller.
[0037] The above embodiments are provided to those skilled in the art to realize or use
the invention, under the condition that various modifications or changes being made
by those skilled in the art without departing the spirit and principle of the invention,
the above embodiments may be modified and changed variously, therefore the protection
scope of the invention is not limited by the above embodiments, rather, it should
conform to the maximum scope of the innovative features mentioned in the Claims.
1. A surge protection device with short-circuit protection function, comprising:
a surge protection module discharging and suppressing a surge current and voltage,
the surge protection module being a plug-in type module;
a short-circuit current protection module integrated in a pedestal and providing short-circuit
protection and plug-in mounting for the surge protection module.
2. The surge protection device with short-circuit protection function according to claim
1, wherein the short-circuit protection module comprises:
a base and a lid, the lid covering the base to form a housing of the pedestal;
a moving contact and a static contact, the static contact including a static contact
bracket;
a lightening sensitive switch connected to the static contact and the elastic connection
piece;
an electromagnetic mechanism including an iron yoke and a coil;
an elastic connection piece including an elastic pin, an upper curved extension part
and a lower extension part;
a baffle plate mounted on the base, the baffle plate and the base forming a self-extinguishing
interrupter;
a first connection terminal connected to an external phase line;
a second connection terminal connected to an external phase line or a ground line;
a first elastic plug and a second elastic plug for connecting to the surge protection
module, the first elastic plug being connected to the first connection terminal and
the second elastic plug being connected to the second connection terminal.
3. The surge protection device with short-circuit protection function according to claim
2, wherein
the static contact bracket is a U shaped rotary bracket and direction of a current
flowing through the static contact is consistent with the direction of a current flowing
through the moving contact;
the coil is connected to a high resistance resistor with a resistance larger than
500mΩ;
the lightening sensitive switch is connected in parallel with the coil and a first
end of the lightening sensitive switch is connected to the static contact bracket.
4. The surge protection device with short-circuit protection function according to claim
3, wherein
the second end of the lightening sensitive switch is connected to an elastic pin of
the elastic connection piece, the elastic connection piece provides an elastic force
for pressing the lightening sensitive switch;
an upper extension part of the static contact bracket is welded to a first end of
the coil at an extension part of the iron yoke;
the upper curved extension part of the elastic connection piece is welded to a second
end of the coil, the lower extension part of the elastic connection piece is connected
to a first elastic plug through a connection piece.
5. The surge protection device with short-circuit protection function according to claim
3, wherein ladder shaped gates are disposed on the baffle plate.
6. The surge protection device with short-circuit protection function according to claim
2, wherein
the moving contact is made of silver tungsten alloy material;
the static contact is made of silver tungsten carbide alloy material.
7. The surge protection device with short-circuit protection function according to claim
2, wherein
the lightening sensitive switch is a ceramic gas discharge tube with a nominal DC
breakdown voltage higher than 250V.
8. The surge protection device with short-circuit protection function according to claim
2, wherein the short-circuit current protection module further comprises a handle,
an operation mechanism, a block plate and a remote alarm device which is optionally
installed.
9. The surge protection device with short-circuit protection function according to claim
2, wherein the surge protection module comprises a first plug plate and a second plug
plate, the first plug plate and the second plug plate are plugged with the first elastic
plug and the second elastic plug.
10. The surge protection device with short-circuit protection function according to claim
2, wherein
a width of the surge protection module is 9mm or 18mm;
the surge protection module has convex edges with different heights on both sides,
the short-circuit current protection module has grooves with corresponding heights
on corresponding surfaces.