Safety locks serve in order that interrupt a chain when current exceeds a certain value, and to protect elements and wires which can be damaged by too strong current. Sharp increase in current is usually caused by malfunction in a chain, most often short circuit. The block of safety locks is located under the dashboard from the driver.

Each of safety locks protects the chain, its belonging to this or that chain is designated on a cover of the block of safety locks.

Fig. 7.2. Example of serviceable and faulty safety locks

Safety locks of knife type which color corresponds to current of protection of a safety lock are installed in the block of safety locks. In case of an exit of any element of electric equipment out of operation, first of all, it is necessary to check a condition of a safety lock. Serviceability of a safety lock is determined by presence of the wire conductor connecting contacts of a safety lock (fig. 7.2).

Fig. 7.3. Special tweezers for extraction of safety locks

For replacement of the failed safety lock previously switch off the corresponding electric chain, take a safety lock from a nest tweezers (fig. 7.3).

If again established safety lock instantly fails when giving tension, check the protected electric chain. If the safety lock protects several chains, then they need to be connected serially that to determine a faulty chain by burn-out of a safety lock.

The heater and the conditioner consume big current therefore the block of safety locks has the switch for protection of their chains. If the chain is disconnected by the switch, switch off a heater and the conditioner before pressing the button of repeated turning on of the switch.