Circuit structure capable of avoiding live replacement of AC220V limit switch
By designing a parallel circuit structure and using an air switch, the signal instability and electric shock risk during live replacement of AC220V limit switches were resolved, achieving a safe and efficient limit switch replacement process.
Patent Information
- Application Number
- CN202520332823.8
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-02-28
- Publication Date
- 2026-01-20
- Estimated Expiration
- 2035-02-28
AI Technical Summary
When replacing an AC220V limit switch while it is energized, there are issues such as unstable signal, risk of electric shock, and complex wiring.
Design a circuit structure to avoid replacing AC220V limit switches while the circuit is energized. Use a parallel circuit to connect the PLC module and the limit switches, and install a No. 1 air switch on each branch. The main control switch is located in the distribution box, simplifying the wiring process.
It enables the replacement of limit switches without power interruption, avoiding signal loss and electric shock risks, and simplifies the wiring and adjustment process.
Smart Images
Figure CN223815919U_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The utility model relates to circuit technical field, concretely is a kind of circuit structure for avoiding live replacement AC220V limit switch. BACKGROUND
[0002] The ironworks of our company includes blast furnace and sintering, and many limit switches and proximity switches are used in the field. Because the area is large, the line between limit switch and PLC is very long, the voltage drop of DC24V power supply is large, and the signal is unstable, so AC220V is used as limit power supply.
[0003] The common end of PLC module is zero line N, which is in the distribution room. The live wire L is sent to the field limit switch, and then returned to the PLC input module. Multiple limit switches share a live wire, which is connected in parallel on the terminal. When replacing the limit switch in the field, if power is cut off, multiple signals will be lost, and if live replacement is performed, there is a risk of electric shock.
[0004] The butt joint of limit switch in the original limit switch junction box and cable from PLC is wrapped with adhesive tape. If the limit switch signal is connected in reverse, the adhesive tape needs to be removed, the connection needs to be adjusted, and then wrapped with adhesive tape, which is time-consuming and laborious UTILITY MODEL CONTENT
[0005] The utility model aims at providing a kind of circuit structure for avoiding live replacement AC220V limit switch to solve the problems raised in the above background.
[0006] To achieve the above-mentioned purpose, the utility model provides the following technical scheme: a kind of circuit structure for avoiding live replacement AC220V limit switch, including PLC module, multiple limit switches, the common end of PLC module is connected to zero line N, one end of each limit switch is respectively connected to the input end of PLC module, the other end is commonly connected to live wire L, to form a parallel circuit, a No. 1 air switch is connected on the branch of each limit switch, and the No. 1 air switch is close to live wire L, a No. 2 air switch is connected as total control switch at the parallel end of all No. 1 air switch branches, the No. 1 air switch and the No. 2 air switch are installed in the inside of a distribution box, and the wiring end of PLC module and limit switch is also located on the wiring terminal strip in the distribution box.
[0007] Preferably, the No. 1 air switch and the No. 2 air switch are both single-pole air switches.
[0008] Preferably, the number of No. 1 air switch and limit switch is two, and the limit switch body is located outside the distribution box.
[0009] Preferably, one of the limit switches is connected to the open-to-position signal of the PLC module, and the other is connected to the close-to-position signal of the PLC module.
[0010] The limit switch is connected with an AC 220V power supply.
[0011] Compared with the prior art, the utility model has the advantages that:
[0012] The circuit structure of the utility model discloses an avoid live replacement AC220V limit switch, the circuit design not only can replace the limit switch without power failure, ensures that the signal is not lost, and the wiring between the limit switch and the PLC is simple, and when the limit switch signal is connected reversely, it is convenient to adjust. BRIEF DESCRIPTION OF DRAWINGS
[0013] Figure 1 The improved circuit structure schematic diagram is shown in the figure.
[0014] Figure 2 The improved circuit structure schematic diagram is shown in the figure.
[0015] In the figure: 1, PLC module; 2, limit switch; 3, No. 1 air switch; 4, No. 2 air switch; 5, distribution box. DETAILED DESCRIPTION
[0016] The technical solutions in the embodiments of the utility model will be clearly and completely described below with reference to the drawings in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, rather than all the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by those skilled in the art without creative labor fall within the protection scope of the utility model.
[0017] Reference Figure 2 As shown: the common end of the PLC module 1 is connected with the zero line N, one end of each limit switch is connected with the input end of the PLC module 1 respectively, and the other end is commonly connected with the fire wire L, thereby forming a parallel circuit, wherein the butt joint of the limit switch and the cable from the PLC is wrapped with adhesive tape and is installed in the limit wiring box (not shown in the figure).
[0018] When the limit switch is replaced on site, power failure will cause multiple signal loss, and live replacement will have the risk of electric shock. If the limit switch signal is connected reversely, the adhesive tape wrapped around the cable joint in the wiring box needs to be torn, and then the wiring is connected, so that the adjustment is difficult.
[0019] Therefore, the improvement is as follows:
[0020] Reference Figure 1, cancel the limit terminal box, install the distribution box 5 in the original position, install 3 1A single-pole air switch inside, connect a No. 1 air switch 3 on each limit switch branch, and the No. 1 air switch 3 is close to the live wire L, and connect a No. 2 air switch 4 as the total control switch at the parallel end of all No. 1 air switch 3 branches. The wiring terminal of PLC module 1 and limit switch 2 is also located on the terminal block in the distribution box 5.
[0021] If the limit switch needs to be replaced, only 3 air switches need to be disconnected, directly replaced, and the risk of live work is avoided. If the limit switch bit signal is reversed, only the last two No. 1 air switches 3 need to be disconnected, and the limit switch connection wire can be adjusted. It is not necessary to remove the rubber cloth, adjust the wiring, and wrap the rubber cloth again, which is time-consuming and laborious.
[0022] Although the embodiments of the utility model have been shown and described, it can be understood by those skilled in the art that various changes, modifications, replacements and variations can be made to these embodiments without departing from the principles and spirits of the utility model, and the scope of the utility model is defined by the appended claims and their equivalents.
Claims
1. A circuit structure for avoiding live replacement of AC 220V limit switches, comprising a PLC module (1) and a plurality of limit switches (2), wherein the common end of the PLC module (1) is connected to a zero line N, one end of each limit switch (2) is respectively connected to an input end of the PLC module (1), and the other end is commonly connected to a fire line L to form a parallel circuit, characterized in that: A No. 1 air switch (3) is connected on the branch of each limit switch (2), and the No. 1 air switch (3) is close to the live wire L, and a No. 2 air switch (4) is connected on the merging end of all the branches of the No. 1 air switch (3) as a total control switch, the No. 1 air switch (3) and the No. 2 air switch (4) are installed in a distribution box (5), and the wiring terminals of the PLC module (1) and the limit switch (2) are also located on the terminal block in the distribution box (5). 2. The circuit structure for avoiding live replacement of AC 220V limit switch according to claim 1, characterized in that: The No. 1 air switch (3) and the No. 2 air switch (4) are both single-pole air switches.
3. The circuit structure for avoiding live replacement of AC 220V limit switch according to claim 1, characterized in that: The number of the No. 1 air switch (3) and the limit switch (2) is set to two, and the main body of the limit switch (2) is located outside the distribution box (5).
4. The circuit structure for avoiding live replacement of AC 220V limit switch according to claim 1, characterized in that: One of the limit switches (2) is connected to the open-to-position signal of the PLC module (1), and the other is connected to the close-to-position signal of the PLC module (1).
5. The circuit structure for avoiding live replacement of AC 220V limit switch according to claim 1, characterized in that: The limit switch (2) is connected to an AC 220V power supply.