DE2306621C3 - Test device for residual current protective circuits - Google Patents

Description

f ³

_{m is} waived, which is currently on the Morkt measured parallel to the B ^e 'ö ^st "" | ^ iderstand ⁹ + * JJ

Sensitive testing devices do not meet these requirements, one presses the key, then Ieg ^ m.t Jm Beside

in all points. Devices that only have a chip resistance U in series as an ammeter,

voltage measurement work, are due to the incomplete- The load resistance viewed au; the aen

to reject the examination. Devices with pre-test buttons 5, display of a Fixwidewtandes9 and mjpb Rege

have, as already mentioned, security resistance 10. The «» JJf

Disadvantages and a simultaneous measurement of current resistance 10 will be rei

SÄ SÄ S iÄÄ SAS SSftt »

^{so that the test device is expensive io} ^ t £ ^ £

The present invention aims to achieve maximum value. maximum effective reasons to avoid the disadvantages listed above- If one calculates "» t wner roaximai ^ π »-π» den This is according to the invention with a test device voltage of 220 V _{in the} test circuit, f ^^ mMmaw for fault current protection circuit, consisting of 15 times 22 mA Prufstrom to Begin, an arrangement for measuring current and voltage may then ^ the resulting voltage, as well as advantages and shunts, and addition of resistors in ^ «dene ⁸ n a is variable, for determining the system ^^^^ . ^^ "^^^ ΐΐ ^ zi earth resistance of the protected system and the test process itself plays like t <°> 8 ^ι *? only one measuring mechanism on an outer conductor and the ^ utele.ter possessed, which places over a switching element, for example one. The Spanungsmesser /e.?,t the = ^N ^ oltage to TASI, rotary or toggle switches, the "* *" ^ "" a return by itself or in OVoIt for ^ J? * ™ "un its initial position, from the voltage "- dangerous current through the earth. If the measuring arrangement is on a current measuring arrangement, the connection resistance 13 can be switched over via fi ^ jg ™ ^ and that the actuating element can be used, or is the protective conductor un ^ ^rbr changeable resistance after release by the bocht the voltage; at the _L ^Me f '^ X operator by a spring in its rest position and the error is recognized ^ V £ stood from the series and shunt resistances in the test resistor 10 against the force ^ rHöernicK circuit with the actuator of position 12 reset f 8 «™«

circle when the actuator of the position 12 is reset. One regulates ^

Rheostat is not less than 10,000 ohms. increasing earth tension caused by the ^ f 8 «™«

This automatic resetting of the control gear on the voltmeter is activated from. Be üe

Resistance ensures that at the beginning of the 3000 ohms mark of the rain W zc.gt der

i d il Wt d Blastungs 35 voltmeter exactly the JjSJJJE '

Resistance is ensured that at the beginning of 3000 OhmM g ^

Always check the maximum value of the stress 35 voltmeter exactly that

Resistance is in the test circuit. As a result, with the We.terrege η must the

the safety of the test, because this before the prescribed E

maximum value of the load resistance as large as 24 V or 65 V, '^^ JfflJ ^ k

is that after the test voltage has been applied, the voltage also exceeds the specified MaX _1n valley

In the worst case only a current to flow 40 then the earth resistance 13 is still and muli

comes that is harmless and, for example, in the area of improvement. ..... _{In the} " _haUtast e 7 _ee -

Is close to the seizure threshold (10 to 25 mA). After this check, the original key is pressed

When the current is turned up, one is pressed. You can also use it in the cheek be certain position of the actuator of the easier handling of the Ge ™ ^ veme ^ lb "

When the current is turned up, one is pressed. Si Ba ^ e

certain position of the actuator of the easier handling of the Ge ™ ^ veme ^ lb "be

Rheostat has a value resulting from 45 The actuator of the rain resisting 10 is

Reach the series and shunt resistances that the dabe, through the spring 12 ^to ™ ^ck 8 " ^te ""_; J J ^

the harmless Slrom νor is used again in the various national regulations. be sp. ^ we se

standardized value of the body resistance, for example 22 mA that of the measuring mechanism, dasjetot aU ^Str ™ ^s ^

wise 3000 ohms, corresponds. In this position switched «! Is displayed. ^W 'J ^de ™ J ₀ ^ ™ "r

If the voltmeter then shows the prescribed ₅ o by means of the resistor 10 J ^oc ^ «8 ^ woj; ^fl «

moderate ^ orderly contact voltage. This circuit breaker must trigger before its trigger

The position can be marked and thus the test nominal residual current is reached.

device Lch a, s contact _voltage meter ve, ^^ _{9ΐ ^^^ Ώ} ^^ Ά _ί

According to Fig. 3, the test circuit of such 55 is the practice ^ J ^ \ _t ^^^ _e £ J ^^.

The device is constructed in such a way that the measuring mechanism 6 first switches off two measuring areas by means of a switch

switched. If the button 7 is not pressed, the 60 layers are perfect and with Measuring mechanism via the series resistor 8 as voltage material expense.

1 sheet of drawings

Claims (1)

instruments 3 and 4 measured - If the patent claim is regulated: load resistance X to lower values, i.e. if ^F the current increases, then the voltage drop test device for residual current protective circuits, at the earth electrode and the differential voltage, which results from an arrangement for measuring 5 Mains voltage to earth less earth earth voltage, current and voltage, as well as from pre- and secondary determinations, decreases. This differential voltage is indicated by the resistors, one of which can be changed, by the voltmeter 4. It can be used to determine the earthing resistance of the scale directly to measure the earthing voltage of the protected system and the tripping current. This method is the only one that will ever applied zei ch η et that the tester can only be a measuring mechanism and is therefore highly promising in practice has the residual-current circuit breaker, characterized marked io j _m built-up area (6), which via a switching element (7) applies. .
for example a push button, rotary or toggle switch, the circuit according to FIG. 2, which in theory would have advantages that would return to its original position by itself, uses an auxiliary probe 5 to measure the earth from the voltage measuring arrangement to a current voltage got to. activating organ of the changeable resistance For this reason alone, it could only be returned to its rest position by a spring (12) after approval by the operator, for example in rural areas, in open terrain. However, it also requires a much greater v> d, with the resulting resistance 20 taking more time to install the series and shunt resistors (8, 9, 10 deneline and in practice it can nevertheless lead to faulty and 11) in the test circuit deferred measurements, namely whenever the voltage line is less than 10,000 ohms due to the actuating element of the control resistor (10) non-metallic lines in the earth. ter the protective earth is confusing and therefore as the probe is set incorrectly. This circuit will therefore hardly used in practice. Most test devices therefore use the circuit according to FIG. 1, with preliminary test buttons The invention relates to a test device for attempts to measure the current strength slowly from fault current protection circuits. These protective circuits begin to increase, until the level of voltage drops that can be read off in the technology of protective measures, measuring instruments, become more important or the FI circuit breaker is triggered. Most of the time, tung. It is therefore important to dispense with a current measurement after one has been completed,
electrical system, these protective measures also occur as is known in practice, to check effectively and properly. The pre-test buttons can be confused because aspects such as the simplicity of the test, if possible _also a specialist, does not work every day with such a short test duration and, above all, the harmlessness of devices and therefore easily when pressed are of great importance. Keys can make a mistake. On the other hand is The current state of the art in this field is the test of the Fl-Schutijchaltung without electricity is on the one hand not perfect due to the various measurements. It can be relevant national regulations that the protective earth resistance is small, namely on the other hand, through a number of test devices, with much less than the legal value. Regulates who are attempted to carry out this prescribed test fations to meet. the earth stress remains low, although a damaging The regulations now stipulate a number of test methods for fl-circuit breakers, which can, however, all more or less have major disadvantages far beyond their tripping faults. For example, an I is _1n . Take the following example: Testing a switch with fixed resistors is not without risk. It with /, "= 0.1 A would be so bad that it is only necessary when it detaches from an outer conductor at 1 A. If the system has a protective earth via the test resistor, the voltage to the resistance of 20 ohms, then the earth cr in order must explain that the tripping nominal fault currents of the ren, although the circuit breaker is already faulty, circuit breakers start flowing, for example, and a complete failure is expected shortly, e.g. 100 mA, 300 mA or even 500 mA. 1st is now 55 can. A current measurement is therefore always interrupted and touches the protective conductor. While checking the systems - but since two measuring instruments are hardly equal parts, so can be read by the test with fixed, the correct test method exists serious accidents would occur, as is the case with the Fl protection circuit in two steps. First has actually already been the case. 60 must be determined that the earth resistance Is below the legal value due to the various national regulations; after that is there are two test circuits for testing the circuit breaker to check whether it is off Fl protection circuits have become known that in release current within the prescribed tolerances Figs. 1 and 2 are shown schematically. zcn lies. The most important requirement is the In the method according to FIG. 1, the test and finally must be about a 65 dangerousness changeable load resistance 1 current also taken into account from an economic point of view the protective earth resistor 2. Be there, because the test device must not cost so much the current and voltage with the help of the display that on its purchase because of the too high price