JPH03270637A - Noise surge protective device - Google Patents

Abstract

PURPOSE:To protect electronic instruments from external abnormal voltage or noise by a method wherein surge absorbers are connected between respective phases of power supply lines as well as between one phase and a grounding unit, coils are connected to respective phases while capacitors are connected between respective phases as well as between respective phases and the grounding unit in the load side of the coils. CONSTITUTION:An external abnormal voltage is absorbed by surge absorbers 7a, 7b. The normal mode component of an external noise voltage is absorbed by a capacitor while the component of common mode is absorbed by capacitors 9b, 9c. Thus, a load 1 is surely protected from the external abnormal voltage or a noise voltage from an external source. Further, when the external abnormal voltage has become higher than the surge resistant voltage of the surge absorbers 7a, 7b, a fuse 6a is cut by fusion and the damage of the surge absorbers 7a, 7b can be prevented.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a noise surge protection device. The present invention relates to a noise surge protection device.

[Prior Art] This type of conventional noise surge protection device connects a surge absorber between the power lines of each phase connected to the load, and between the power line of each phase and the ground. , which was designed to absorb external abnormal voltage. By the way, in this conventional noise surge protection device, when the external abnormal voltage exceeds the surge withstand capacity of the surge absorber, the surge absorber breaks down and becomes short-circuited, resulting in burnout or damage to external equipment. There was a problem.

Furthermore, when such conventional noise and surge protection devices are installed in a power distribution board, etc., and various tests such as insulation tests and withstand voltage tests are performed, the surge absorber may burn out in the same way as in the case described above. There was a problem.

Therefore, although various breakthrough measures have been taken to overcome these difficulties, none of them are particularly noteworthy, and for example, the effectiveness against noise at low voltage levels has been limited. The problem was that it was not that high. Also, in order to eliminate noise, it is considered to insert a capacitor between the power supply line and the housing, but in this case, it is necessary to 2
Another drawback was that it required the use of extremely high voltage resistance such as kV.

[Problems to be Solved by the Invention] Although the conventional noise and surge protection device described above is equipped with a surge absorber, when the external abnormal voltage exceeds the surge withstand capacity of this surge absorber, the surge absorber is destroyed. However, there was a problem in that it could become short-circuited, resulting in burnout or damage to external equipment. In addition, when such conventional noise surge protection devices are installed in power distribution boards, etc., and various tests such as insulation tests and withstand voltage tests are performed, there is a problem that the surge absorber burns out in the same way as in the above case. There was a point.

Furthermore, although it has been considered to insert a capacitor between the power supply line and the equipment housing to eliminate noise at relatively low voltages, in this case, it is necessary to However, there was also the problem that a material with extremely high pressure resistance had to be used.

This invention has been made to solve the above-mentioned problems, and by appropriately arranging coils and capacitors, it is possible to prevent, for example, external abnormal voltages and noises superimposed on the auxiliary power supply. The purpose of the present invention is to obtain a noise surge protection device that can reliably protect electronic equipment.

[Means for Solving the Problems] A noise surge protection device according to the present invention includes: a casing that houses a load; a plurality of power supply connection terminals that are attached to the casing and connect the load and a power source; and the casing. A connection terminal device consisting of a ground connection terminal for grounding the power source: a fuse inserted into one phase (or each phase) of the power line connecting the power source connection terminal and the load;; between the fuse and the load; A surge absorber connected between each phase of the above power line and between one phase (or each phase) of the above power line and the grounding part; a coil connected at each phase of the above power line; and a load of the above coil. The device is characterized by comprising a capacitor connected between each phase of the power supply line and between each phase of the power supply line and a ground portion on the side.

[Function] In the present invention, by appropriately arranging coils and capacitors in the circuit, it is possible to reliably protect electronic equipment from, for example, external abnormal voltages and noises that are superimposed on the auxiliary power supply. can.

[Embodiment 1] FIG. 1 is an electrical wiring diagram showing a noise surge protection device according to a first embodiment of the present invention. In FIG. 1, a load (1) is housed in a housing (2). Also,
A connection terminal device (3) is also attached to this housing (2), but this connection terminal device (3> is made up of power supply connection terminals (3a), <3b>, and relay connection terminals (3).
c), and a ground connection terminal (3d), and
The electric wires (4a) and (4b) are connected to the power supply connection terminal (3a)
), (3b) are connected to the load (1). The switch (5a) and the fuse (6a) are connected in series and inserted into the proper position of the power line (4a). Here, the switch (5a) inputs only the negative phase of the power line (4a). The surge absorber (7a) is connected between the power line (4a) and (4b), and the surge absorber (7b) is connected between the power line (4a) and the relay connection terminal (3c). Also, each power line (4
Coils (8a) and (8b) are inserted into appropriate positions of a) and (4b). Furthermore, the power line (4a) and the t source! ! (4
A capacitor (9a) is connected between the power supply &
! A capacitor (9b) is connected between (4b) and the relay connection terminal (3c), and the power supply 1! (4a)
A capacitor (9c) is connected between the and relay connection terminal (3c).
is connected. The connection terminal <13> is attached to the housing (2>), and is connected to the ground connection terminal (3d) with an appropriate connection wire (12>.
) is for grounding the ground connection terminal (3d), and the shorting device (1) is for connecting the relay connection terminal (3C) to the ground connection terminal (3d).

Next, the operation of the apparatus of the first embodiment will be explained. First, by connecting an appropriate auxiliary power source ((21 not shown) to the power supply connection terminals (3a) and (3b), and then closing the switch (5a), the said auxiliary power source for the load (1) is connected. Apply power.

At this time, even if an external abnormal voltage or an external noise voltage is superimposed on the auxiliary power supply, these are absorbed as described below, and the load (1) is reliably protected. That is, external abnormal voltage is applied to surge absorbers (7a) and (7b).
absorbed by. Regarding external noise voltage, its normal mode component is absorbed by the capacitor (9a), and the common mode component is absorbed by the capacitor (9b).
, (9c). Thus, the load (1)
is reliably protected from external abnormal voltages and external noise voltages.

Furthermore, the external abnormal voltage is applied to the surge absorber (7a).
, (7b), the fuse; (6a) blows and the corresponding surge absorber (7a)
), (7b) is prevented.

Here, execution of the insulation test or withstand voltage test for load (1) will be explained. First, remove the short circuit device (11) from the relay connection terminal (3c) and the contact and male connection terminals <3d>, and connect the ground side of the surge absorber (7b> and capacitors (9b), (9C) 77) to the housing (2). In this state, apply a predetermined voltage between the power supply connection terminal (3a) and the case (2) or between the power supply connection terminal (3b) and the case (2>). , Negative?!ii' (1).By doing this, the surge absorber (7b) and capacitor (7b) and capacitor (
9b) and (9c) can be reliably prevented.

FIG. 2 is an electrical wiring diagram showing a noise surge protection device according to a second embodiment of the invention. The configuration shown in FIG. 2 is similar to that of the first embodiment described above, except for the following matters.

(a) Switch (5b) and fuse (6b) are connected in series to create a power supply! (4b) is also inserted in the proper place; and (b) The surge absorber (7c) is also connected between the power line (4b) and the relay connection terminal (3C>).

Note that the switch (5b) is arranged to work in conjunction with the switch (5a).

Next, the operation of the device of the second embodiment will be explained. First, connect an appropriate auxiliary power supply (not shown) to the power supply connection terminals (3a>, (3b), and then switch (5)
By closing a) and (5b), the auxiliary power is applied to the load (1).

At this time, even if an external abnormal voltage or an external noise voltage is superimposed on the auxiliary power supply, these are absorbed as follows, and the load (1) is more reliably protected.

g, external abnormal voltage can be handled by surge absorber (7a), (7
b) and (7c). Regarding external noise voltage, the normal mode component is absorbed by the capacitor (9a), and the common mode component is absorbed by the capacitors (9b) and (9C). In this way, the load (1) is more reliably protected from external abnormal voltages and external noise voltages.

Furthermore, the external abnormal voltage is applied to the surge absorber (7a).
, (7b) and (7C), the fuses; (6a) and (6b) are blown.
The surge absorbers (7a), (7b) and (7c)
> damage is prevented.

Here, execution of the insulation test or withstand voltage test for load (1) will be explained. First, remove the short circuit device (11) from the relay connection terminal (3c) and the ground connection terminal (3d), and connect the ground sides of the surge absorbers (7b), (7C) and capacitors (9b), (9C) to the housing (2).
〉, and in this state, apply a predetermined voltage between the power connection terminal (3a) and the case (2) or between the power connection terminal (3b) and the case (2). Then, perform the required insulation test or withstand voltage test for load (1).

By doing this, the surge absorbers (7b), (7c) and capacitors (9b), (
9c) damage can be reliably prevented.

[Effects of the Invention] As explained above, the noise surge protection device according to the present invention includes: a casing for storing a load; attached to the casing;
A connection terminal device consisting of a plurality of power connection terminals that connect the load and the power source, and a ground connection terminal that grounds the housing; one phase (or each phase) of the power line that connects the power connection terminal and the load ); a surge absorber connected between each phase of the power line and between one phase (or each phase) of the power line and the ground between the fuse; and the load; A coil connected to each phase of the power line; and a capacitor connected between each phase of the power line and between each phase of the power line and the ground on the load side of the coil. With the above features, abnormal voltages and noise voltages from the outside are reliably absorbed, and damage to the surge absorber is reliably prevented even when the external abnormal voltage exceeds a certain allowable value. Furthermore, damage to the surge absorber and capacitor during various tests can be reliably prevented.

[Brief explanation of drawings]

FIG. 1 is an electrical wiring diagram showing a noise surge protection device according to a first embodiment of the present invention, and FIG.
FIG. 2 is an electrical wiring diagram showing a noise surge protection device according to an embodiment. (1) is the load, (2) is the housing, (3) is the connection terminal device, (3a), (3b) is the power supply connection terminal, (3c) is the relay connection terminal, (3d) is the ground connection terminal, (4a) ), (4b) are power lines, (5a), (5b) are switches, a), (6b) are fuses;, a>, <71)), (7c) are surge absorbers, a)
, (8b) is a coil. a), (9b), and (9c) are capacitors, 0) is a grounding wire, l> is a short circuit device, 2) is a connecting wire, and 3) is a connecting terminal.

Claims (2)

[Claims] (1) A casing that houses the load; A connection terminal device that is attached to the casing and includes a plurality of power connection terminals that connect the load and the power source, and a ground connection terminal that grounds the casing; The power supply connection A fuse inserted into one phase of the power line connecting the terminal and the load; A fuse inserted between each phase of the power line and between one phase of the power line and the ground between the fuse and the load. a surge absorber; a coil connected to each phase of the power line; and a capacitor connected between each phase of the power line and between each phase of the power line and the ground on the load side of the coil; A noise surge protection device characterized by: (2) A casing that houses the load: A connection terminal device that is attached to the casing and includes a plurality of power connection terminals that connect the load and the power source, and a ground connection terminal that grounds the casing; The power supply connection A fuse inserted into each phase of the power line connecting the terminal and the load; A fuse inserted between each phase of the power line and between each phase of the power line and the ground between the fuse and the load. a surge absorber; a coil connected to each phase of the power line; and a capacitor connected between each phase of the power line and between each phase of the power line and the ground on the load side of the coil; A noise surge protection device characterized by: