DE19525370A1 - Method for magnetising fault current circuit breaker - magnetising trip release at specified voltage, measuring release current, determining relevant demagnetising voltage, demagnetising at this voltage. - Google Patents

Abstract

The method involves first magnetizing the trip release with the voltage specified for the particular release type and/or protection switch and measuring the tripping currents (I DELTA). The demagnetizing voltage (U abm) is determined as a function of the measured tripping current and the switch type and demagnetize with that demagnetizing voltage. The tripping current is then measured and (a) if it lies within a specific current range (A) and (b) if it does magnetisation is complete, and (c) if the leakage current is above an upper limit (I o) demagnetize again with the higher voltage. If 9d) the current is below a lower limit (I u) magnetize without changing the voltage and demagnetize with the de-magnetizing voltage (U abm). Repeat (a) and if necessary (c) and (d) until such time as the current lies within the range specified (a).

Description

The invention relates to a magnetizing method according to the preamble of the An Proverb 1. Such methods are used in the manufacture of residual current circuit breakers with permanent magnet releases. With the magnetization process Tripping characteristic of the residual current circuit breaker set.

Residual current circuit breakers with magnetic tripping relays are for example in EP-A2-0590 545. It is stated there that in residual current circuit breakers Locking or holding magnet releases are used, the armature of a permanent magnets pulled against the force of a spring on the yoke of the release relay coil becomes. At the moment of release, stored energy is used to generate a current flow and thus uses a magnetic flux that opposes the permanent magnetic flux is directed and causes the armature on the magnetic release to fall off.

The trip characteristic of the release is by a magnetization process of the permanent magnet adjustable.

A magnetizing method used in production for a long time is explained below with reference to FIG. 4. A prior publication of the method is not known.

Fig. 4 shows a flow chart of the procedure of a magnetization and demagnetization. In this case, a magnetization device is given a magnetization voltage of, for example, 1000 V, and a demagnetization voltage of, for example, 250 V. Thereafter, magnetization and then demagnetization are each carried out with the predetermined voltage. The tripping current I _{Δ of} the residual current circuit breaker is then measured. In the next step, it is checked whether the measured value I _Δ lies within a permissible range which is determined by a lower limit value I _u and an upper limit value I _o .

If the measured value I _{Δ is} greater than the upper limit value I _o , a renewed magnetization is unnecessary, a repeated demagnetization step is carried out with an increased demagnetization voltage.

If the measured value I _{Δ is} smaller than the lower limit value I _u , magnetization is carried out again with the originally used magnetization voltage and he is again demagnetized with a reduced demagnetization voltage. The determination of the voltages to be used in each further step (n + 1) can be carried out using the interval bisection method

U _{n + 1} = U _n (1 ± 2 ^-n )

or by another division procedure

U _{n + 1} = U _n (1 ± 2 ^-kn )

respectively.

The described method has the disadvantage that the electrical apparent power of the Trigger during the magnetization process can not be considered. Already at A small spread of the magnetizing current scatter the apparent powers and thus the response values so strong that it is often required in the course of production is necessary to re-magnetize the trigger.

The invention is therefore based on the object of specifying a magnetizing method, which is a setting of the tripping current in a comparatively narrow tolerance band enables.

This object is achieved in a method according to the preamble of claim 1 its characteristic features solved.

An advantage of the method is that any tripping current value is internal half of the VDE limits can be set with a very narrow tolerance band. Another The advantage is that very high and very low apparent powers can be seen and the associated devices can be sorted out. In addition, ge shows that compared to the previous method fewer demagnetization cycles required are.

The method according to the invention is described below with reference to the drawing figures explained. It shows:

Fig. 1 tripping current characteristics depending on the voltage Abmagnetisierungs for different devices,

FIG. 2 process steps of the invention Magnetisierverfahrens,

Fig. 3 apparent power characteristic curves in dependence on the approximately Abmagnetisie voltage for different devices,

Fig. 4 steps of the previous magnetization process.

The invention is based on the knowledge that a triggering range in a narrow current range can be achieved by setting a suitable demagnetizing voltage. The tripping current I _{Δ of} a residual current circuit breaker is inversely proportional to the demagnetization voltage. The lower the demagnetization voltage, the higher the tripping current.

In Fig. 1 the relationship between demagnetization voltage U _abm and trigger current I _Δ for several different devices a to d is shown. It can be seen that in the fully magnetized state of the release (U _abm = 0), the release currents I _{Δ vary} within wide limits, namely for devices a to c in the range from 35 to 80 mA, with inclusion of the device d to 1240 mA ( not readable in Fig. 1).

Of FIG. 1 it can be seen that it is possible to adjust by means of device-specific choosing a suitable Abmagnetisierungsspannung a trigger current in a mandatory Financial trigger area A, for example, between 15 mA and 30 mA. As a rule, a single demagnetization step will suffice to make the desired setting.

Fig. 2 shows the operation steps of the inventive Magnetisierverfahrens. After the start, the respective release is magnetized and the release current I _Δ is then measured. A demagnetization voltage is selected as a function of the measured tripping current I _Δ and the device type, specifically with the aid of characteristic curves of the type shown in FIG. 1, which are stored in a microcomputer the tripping current I _{Δ is} measured. It is checked whether the condition I _u <I _Δ <I _{o is} fulfilled. If so, the magnetization process itself is ended, but it is possible to repeat the test step several times for checking. If, contrary to expectations, the test condition is not fulfilled, the voltages are changed up and down, as has already been explained with reference to FIG. 4.

Pulses are used for magnetizing, with different pulse shapes (preferably pure sine) and pulse curves (in terms of amplitudes and number of Impulses) are possible. However, similar pulse sequences (with in the Sum of the same energy content of the pulses) can be used.

The method makes it possible to classify devices to be magnetized (triggers), ie to divide them into different classes. Here, for. B. Devices according to the characteristic curve d in Fig. 1 are sorted out, if, for example, demagnetization voltages above 100 V are not desired.

The method according to the invention also enables the apparent power of a Set the trigger by selecting the demagnetization voltage or devices with to recognize and sort out very high or very low apparent power.  

Fig. 3 shows characteristics of different devices A to D, the apparent power S is plotted as a function of U Abmagnetisierungsspannung _ABM.

If in a microcomputer to control the magnetization process except the off dissolving current characteristics also the apparent power characteristics can be stored on due to the demagnetization voltage used on the apparent power of the of the respective device.

Claims (6)

1. Method for magnetizing a residual current circuit breaker with a permanent magnet release, characterized by the following steps:

• a) magnetizing the trigger with a voltage specified for the respective trigger type and / or device type;
• b) measuring the tripping current (I _Δ );
• c) determining the demagnetization voltage (U _abm ) as a function of the measured tripping current (I _Δ ) and the device type;
• d) demagnetizing with the demagnetizing voltage (U _abm ) determined in step c);
• e) measuring the tripping current (I _Δ ) and checking whether the tripping current (I _Δ ) is in a tripping current range (A) defined as permissible and
• e1) if yes, end the magnetization, or
• e2) if the tripping current (I _Δ ) is greater than an upper limit value (I _o ), demagnetize again with an increased voltage value or
• e3) if the tripping current (I _Δ ) is less than a lower limit value (I _u ), magnetize with unchanged voltage and then demagnetize with the demagnetization voltage (U _abm ) determined in step c), and
• Repeat steps e) and, if applicable, steps e2) and e3) until step e1) is reached.

2. The method according to claim 1, characterized in that for opening and Demagnetize a sequence of sinusoidal voltage pulses is used. 3. The method according to claim 1 or 2, characterized in that the chip for repeated magnetization and demagnetization after a division process be determined. 4. The method according to one of the preceding claims, characterized in that in step c) the demagnetization voltage is determined with the aid of a microcomputer and the characteristic curves stored therein (U _abm = f (I _Δ )) for different trigger types and / or device types. 5. The method according to any one of the preceding claims, characterized in that trigger type-specific apparent power characteristics (S = f (U _abm )) who used to, based on the measured trigger current (I _Δ ) on the apparent power (S) to close and, if necessary, to sort out triggers on the basis of a seemingly impermissible apparent power. 6. The method according to claim 1, characterized in that after the first Magnetization defines magnetized and then according to steps b) to e4) is proceeded further.