14.3. Safety locks - the general information
Various combinations of safety locks, fusible inserts and breakers of a chain are applied to protection of contact chains of electric equipment of the car. The main assembly block is installed in a motive compartment, one more assembly block of the relay and safety locks is located in interior of the car, under the dashboard.
Various combinations of safety locks, fusible inserts and breakers of a chain most of which part is concentrated in two assembly blocks are applied to protection of contact chains of electric equipment of the car (see Specifications).
Each separate safety lock is used for protection of any concrete electric contour or at once several contours. The label with the ID card of placement of safety locks in the assembly block is usually glued to a cover of the last, from its internal party.
In assembly blocks the safety locks of a compact design equipped with bayonet contact plugs, and which if necessary are easily taken by fingers from the nests in the block are located. At refusal any of consumers of the electric power first of all it is always necessary to check a condition of the corresponding safety lock. Turn a key in the ignition lock in position of ON and by means of a lamp sampler probe open plugs of each of safety locks. If the lamp lights up at connection to each of plugs, therefore, a safety lock as it should be. If tension takes place only from giving of food, so the safety lock fused. Let's notice also that usually the case of a safety lock is manufactured of transparent plastic through which it is easy to define a condition of a working crossing point.
The fact of burn-out of a contact crossing point of the failed safety lock easily is elicited at visual survey of its translucent case
When replacing of the fused safety lock strictly you watch that the established replaceable corresponded on the type which left from an element. The safety locks calculated on various nominal current physically can differ in nothing from each other, without being at the same time interchangeable. Each of electric chains has various working parameters and needs various degree of protection therefore replacement of the safety lock (calculated on a certain current) not corresponding to it in parameters is fraught with the most serious consequences (up to fire emergence). Working parameters of a safety lock (nominal current) are usually designated on its plastic case.
If the new safety lock at once after installation also fails, it does not make sense to make its further replacement, - before it is necessary to reveal and remove the cause of an overload in a chain. In most cases that appears the short circuit of a connecting electrical wiring caused by damage of its isolation.