【０００１】
【考案の属する技術分野】
本考案は低圧電路の分電盤に設置した絶縁劣化警報信号等を受電室ないしは遠隔地に位置する監視所に伝達する方法に関する。
【０００２】
【従来の技術】
従来は受電室から監視所への信号伝達はＢ種接地線を利用しての方法は行われていたが、分電盤に設置された絶縁監視装置から受電室への伝送は個別の伝送路を布設しこれを介して信号を送信していた。又は電気設備管理者の巡視点検時に確認する方法等がとられていた。
【０００３】
【考案が解決しようとする課題】
しかしながら、上述の如き布設工事を伴う方法は経済的負担が大きいのみならず、布設時において活線工事では危険が伴い、停電での作業では時間的制約があった。巡視点検での管理では事故時の敏速な対応が出来ず問題が大きくなることがあった。
【０００４】
【問題を解決するための手段】
上記の課題を達成するため、キュービクル等受電室から分電盤内に配線されているＤ種接地線と電路の接地相間にコンデンサ又はコンデンサと直列にインピーダンスを接続させ、キャリア送出ＣＴを使用して前記接地線と接地相間に搬送信号を重畳させ、受電室のＢないしＤ種接地線で当該信号を検出できるようにしたことを特徴とするものである。
【０００５】
【実施例】
以下本考案の実施例について説明する。
図１は本考案の方式を標準的な低圧電路に設置したときの結線図である。
受電した高圧から低圧には動力用トランス１と電灯用トランス２により３相２００Ｖと単相３線式に分けられ分電盤に配線されている。受電室７ではＢ種接地線３で動力用トランス１の１線と電灯用トランス２の中性線が共通接地されている。アレスタ、高圧機器のケースアースはＡ種接地線４に接続されている。（図１では結線は省略）Ｄ種接地線５は電路には接続されず各分電盤８に配線され分電盤８筐体（フレーム）及び低圧機器のフレームアースに接続されている。ブレーカ６は受電室７の低圧分岐盤（低圧配電盤）に設置されている。受電室７の接地函Ｄ種接地線５には分電盤８からの信号を監視する搬送波吸上用ＣＴ１４が設置されている。受信器１３は検出ＣＴ１４の出力を検出しどの分電盤での異常かを判断している。このブレーカー６までが受電室７に設置されている。分電盤８では入口にＺＣＴ９を設置しこれ以降負荷電路及び機器の絶縁状態を監視している。分電盤８の内部では電路の接地相１５とＤ種接地線５の間にはコンデンサ１１を接続している。コンデンサ１１の値は負荷電流による接地相の電圧降下からコンデンサ１１を通り流れる漏れ電流が機器絶縁劣化の漏れ電流の検出レベルに対し影響のないような小さな容量のものを付けている。接地相（中性線接地相）１５とＤ種接地線５の間にはキャリア送出用ＣＴ１２を付け漏電検出器１０からの信号を受電室７のＤ種接地線５に絶縁劣化状態を監視するよう待機している。
【０００６】
分電盤８の負荷側で絶縁劣化により漏れ電流が発生するとＺＣＴ９で零相電流として検出し出力が発生する。この出力は検出・送信器１０に入力され、その大きさが設定値を超えた時、固有の警報信号を発生しキャリア送出ＣＴ１２に出力される。注入された信号電圧は分電盤８の動力用接地相１５を通り受電室７のＢ種接地線３を介し、大地抵抗１７を通りＤ種接地線５を通り分電盤８に戻る。受電室で設置されている監視する搬送波吸上用ＣＴ１４ではキャリア送出ＣＴ１２からの固有の信号を検出し分電盤８を識別する。分電盤の数が多いときは各分電盤のコンデンサ１１の容量とＢ種接地線３とＤ種接地線５における線経及び亘長によって決まる抵抗値との間の大地接地抵抗１７によりキャリア送出信号レベルが減衰する。加えて、接地線に各種負荷設備によって重畳されるノイズの影響もあり、信号の伝達が悪くなる。そこで各分電盤に設置するコンデンサ１１を適切に選定し各分電盤固有の周波数のみ通過させるフィルタとして最適条件回路を作成することにより信号の伝達は容易になる。
【０００７】
常駐者へは受信器のブザー音で信号の伝達を知ることができ、常駐者は受信器の表示等を見ることにより、どこの分電盤が絶縁劣化を起こしているかを知ることができる。
【考案の効果】
今まで分電盤からの信号の伝送は個別の電線路を布設する方法しかなかったが、本考案により低コストでしかも簡単に確実に伝送を行うことが出来るようになった為、分電盤単位での絶縁管理が行い易くなり、事故時の事故点探査が容易になり電気設備の保守管理業務が大幅に向上した。
【図面の簡単な説明】
【図１】図１は本考案の方式を標準的な低圧電路に接地した時のものである。
【符号の説明】
１ 動力用トランス
２ 電灯用トランス
３ Ｂ種接地線
４ Ａ種接地線
５ Ｄ種接地線
６ ブレーカー
７ 受電室
８ 分電盤
９ ＺＣＴ
１０ 検出・送信器
１１ コンデンサ
１２ キャリア送出ＣＴ
１３ 受信器
１４ 搬送波吸上用ＣＴ
１５ 分電盤側接地相
１６ 分電盤側Ｄ種接地線
１７ Ｂ種Ｄ種接地線間大地抵抗[0001]
[Technical field to which the invention belongs]
The present invention relates to a method of transmitting an insulation deterioration warning signal or the like installed on a distribution board on a low-voltage path to a power receiving room or a monitoring station located at a remote place.
[0002]
[Prior art]
Conventionally, the signal transmission from the power receiving room to the monitoring station has been performed using a class B ground wire, but the transmission from the insulation monitoring device installed on the distribution panel to the power receiving room is a separate transmission line. And a signal was transmitted through this. Alternatively, a method of confirming when the electric equipment manager performs a patrol inspection has been adopted.
[0003]
[Problems to be solved by the invention]
However, the method involving the laying work as described above not only has a large economic burden, but also involves dangers in live-line work at the time of laying, and there is a time limit in work during a power outage. In the case of patrol inspection management, it was not possible to respond promptly in the event of an accident, and the problem was sometimes greater.
[0004]
[Means to solve the problem]
In order to achieve the above-mentioned subject, a capacitor or a capacitor is connected in series with a capacitor or a capacitor between a D-type ground wire wired in a distribution board from a power receiving room such as a cubicle and a ground phase of an electric circuit, and a carrier sending CT is used. A carrier signal is superimposed between the ground line and a ground phase, so that the signal can be detected by a class B or D ground line in a power receiving room.
[0005]
【Example】
Hereinafter, embodiments of the present invention will be described.
FIG. 1 is a connection diagram when the method of the present invention is installed on a standard low-voltage path.
From the received high voltage to low voltage, the power transformer 1 and the lamp transformer 2 divide the power into a three-phase 200 V single-phase three-wire system, which is wired to a distribution board. In the power receiving room 7, one line of the power transformer 1 and a neutral line of the light transformer 2 are commonly grounded by the class B ground wire 3. The arrestor and the case ground of the high-voltage equipment are connected to the class A ground wire 4. (Connections are omitted in FIG. 1) The D-type ground wire 5 is not connected to the electric circuit but is wired to each distribution board 8, and is connected to the cabinet (frame) of the distribution board 8 and the frame ground of the low-voltage equipment. The breaker 6 is installed on a low-voltage switchboard (low-voltage switchboard) in the power receiving room 7. A CT 14 for carrier wave absorption for monitoring a signal from the distribution board 8 is installed on the grounding box D type grounding wire 5 of the power receiving room 7. The receiver 13 detects the output of the detection CT 14 and determines which distribution board is abnormal. Up to the breaker 6 is installed in the power receiving room 7. In the distribution board 8, a ZCT 9 is installed at the entrance, and thereafter, the insulation state of the load circuit and the equipment is monitored. Inside the distribution board 8, a capacitor 11 is connected between the ground phase 15 of the electric circuit and the D-class ground wire 5. The value of the capacitor 11 is such that the leakage current flowing through the capacitor 11 due to the voltage drop of the ground phase due to the load current does not affect the detection level of the leakage current due to the deterioration of the device insulation. A carrier sending CT 12 is provided between the grounding phase (neutral grounding phase) 15 and the D-type grounding line 5, and a signal from the leakage detector 10 is monitored by the D-type grounding line 5 in the power receiving room 7 for insulation deterioration. Waiting for you.
[0006]
When a leakage current is generated on the load side of the distribution board 8 due to insulation deterioration, it is detected as a zero-phase current by the ZCT 9 and an output is generated. This output is input to the detector / transmitter 10, and when its magnitude exceeds a set value, a unique alarm signal is generated and output to the carrier sending CT12. The injected signal voltage passes through the power ground phase 15 of the distribution board 8, passes through the B-class grounding wire 3 of the power receiving room 7, passes through the ground resistance 17, passes through the D-class grounding wire 5, and returns to the distribution board 8. The monitoring carrier CT 14 installed in the power receiving room detects a unique signal from the carrier sending CT 12 and identifies the distribution board 8. When the number of switchboards is large, the carrier is set by the grounding resistor 17 between the capacity of the capacitor 11 of each switchboard and the resistance value determined by the wire length and the length of the class B ground line 3 and class D ground line 5. The transmission signal level is attenuated. In addition, there is also the effect of noise superimposed on the ground line by various load facilities, and signal transmission is deteriorated. Therefore, signal transmission becomes easy by appropriately selecting the capacitor 11 installed in each distribution board and creating an optimum condition circuit as a filter that passes only a frequency unique to each distribution board.
[0007]
The resident can be informed of the signal transmission by the buzzer sound of the receiver, and the resident can see which distribution board is causing insulation deterioration by looking at the display or the like of the receiver.
[Effect of the invention]
Until now, the only way to transmit signals from the distribution board was to lay individual electric lines, but the present invention has made it possible to perform transmission at low cost and easily and reliably. Insulation management on a unit-by-unit basis has become easier, and it has become easier to locate the point of an accident in the event of an accident, greatly improving the maintenance and management of electrical equipment.
[Brief description of the drawings]
FIG. 1 shows the system of the present invention grounded to a standard low-voltage path.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Power transformer 2 Lamp transformer 3 Class B ground wire 4 Class A ground wire 5 Class D ground wire 6 Breaker 7 Power receiving room 8 Distribution board 9 ZCT
10 Detection / Transmitter 11 Capacitor 12 Carrier delivery CT
13 Receiver 14 CT for carrier absorption
15 Distribution board side ground phase 16 Distribution board side D class ground wire 17 B class D class ground wire ground resistance
