DE9006337U1 - NH fuse link - Google Patents

Description

, .. ,. ,. 9OG 3207&Ogr;&Egr;

(j 1 Siemens Aktiengesellschaft

NH - fuse link
5

The innovation relates to a low-voltage, high-performance fuse link, hereinafter referred to as NH fuse link, between whose contact blades in the housing at least one fusible element is arranged, the state of which is monitored by an electrically parallel-connected indicator, in detail according to the generic term of protection claim.

Indicators in the form of spring-loaded indicators have proven themselves in practice and are easy to manufacture and install. 1.5 LM To reduce the risk of accidents when using Nri fuses , NH fuses are increasingly being used. These are fitted with a stress-free gripping strip. The end plates are no longer made of metallic material, but of insulating material. In order to achieve all-round protection against contact, it is necessary to protect all live parts accordingly. This also includes the indicator. It is well known that the indicator can be covered over a large area with a flake of transparent insulating material.

According to another known design, the spring plate indicator is clamped at the end in insulating material and the circuit for the indicator fuse is closed between a contact point on the spring plate via this to a contact point on a contact blade.

The innovation is based on the task of providing a further, particularly simple solution. The solution to the task is achieved according to the innovation by covering the indicator spring with insulating material in areas where contact is at risk. This solution is suitable for indicators of the type of spring plate indicators in a wide variety of designs and in particular for those that are not fundamentally safe from contact due to special design measures. This solution

NO/ Me / 29.05.1990

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ψ ( �L 1 is therefore particularly suitable for conventional fuse inserts available on the market.

In the case of an indicator whose spring plate is in the release position

e 5 If the indicator spring is raised at one end from the end plate, it is advisable to cover the indicator spring at this end with an insulating cap.

£ The stop spring can easily be covered with a shrink tube, at least in the area where there is a risk of contact.

In order to achieve a conspicuous indication of the tripping state _r u, ' (J it is advantageous if the insulating material is provided with colour. For example, the insulating material can be coloured accordingly.

The innovation will now be explained in more detail using an example shown schematically in the drawing:

FIG 1 shows a fuse link in longitudinal section,

FIG. 2 shows the front view with an indicator of a safety insert according to FIG. 1.

' In the fuse link 1 according to FIG. 1, a fusible element 3 extends between contact blades 2. Its state is indicated by an electrically parallel-connected indicating fusible element 4 and an indicator 5 in the form of a spring plate indicator.

If the fuse link is intact, the spring plate of the indicator 5 rests against the end plate 6 with the gripping tab 7. The indicator is then held down by the indicator fuse element. If the fuse element 3 is blown due to over-

load and has melted or has increased its resistance accordingly, the indicator fuse element 4 is overloaded, causing it to melt as well. The

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The spring plate of the indicator 5 can then spring into the indicator position for the used fuse link, which is illustrated by the right position of the indicator 5. The left position shows the indicator in the position of an unused fuse link.

The circuit via the indicator fuse element 4 is established with an unused fuse link from the right contact blade 2 via the indicator fuse element 4 to the left contact blade 2.

The indicator spring is covered with insulating material at least in areas where there is a risk of contact. This ensures that even in cases where the spring-loaded indicator spring is still at potential, a risk from accidental contact is avoided. The indicator spring can in particular be covered with an insulating material cover 7. In the simplest case, the indicator spring is covered with a shrink tube, at least in the area where there is a risk of contact.

In order to be able to quickly identify a fuse link that has been triggered, it is advantageous to provide the indicator's insulating material with a correspondingly conspicuous color. In particular, the insulating material can be colored accordingly. Insulating materials with corresponding mechanical properties that have the required high electrical breakdown strength are suitable.

Claims (5)

90 6 3 2 0 7 OE Protection claims 1. NH fuse link (1), between the contact blades (2) of which at least one fusible element (3) is arranged in the housing, the condition of which is indicated by an electrically parallel-connected indicator fusible element (4) and indicator (5) in the manner of a spring plate indicator, characterized in that the indicator spring is covered with insulating material (e.g. insulating material cover 7) in areas where contact is at risk. 10 2. NH fuse link according to claim 1, characterized in that the indicator spring is covered with an insulating cover (7). 3. NH fuse link according to claim 1 ₁ , characterized in that the indicator spring is covered with a shrink tube at least in the area where there is a risk of contact. 4. NH fuse link according to claim 1, characterized in that the insulating material is provided with paint. 5. NH fuse link according to claim 4, characterized in that the insulating material is colored ( .