The electrical equipment system of KamAZ vehicles is single-wire with a rated voltage of 24 V. The negative poles of current sources and current consumers are connected to the vehicle ground
The negative terminal of the batteries is connected to the vehicle ground through a switch, so all electrical consumers work only when the batteries are connected to ground.
For reliable contact between the cab and the frame, the frame and the engine, additional ground wires are used.
In the general scheme of electrical equipment, groups of devices can be distinguished that form independent systems, the most important of which are the power supply system, which includes:
- -batteries and generator set with voltage regulator;
- - engine starting system, consisting of a starter, batteries and starting aids;
- - a system of instrumentation, which includes a speedometer, a tachometer, instruments for measuring temperature, pressure, fuel level and current strength, as well as systems for external and internal lighting, light signaling, heating, sound signaling and glass cleaning.
Some devices cannot be clearly classified into systems and can be classified as accessories.
Switches, switches, relays, fuses, connection panels and plug-in connections belong to the switchgear group and are included in all systems.
On the electrical diagrams, next to the digital designation of the wires, their color is indicated in letters: B - white, D - blue, G - yellow, 3 - green, R - red, KCh - brown, O - orange, R - pink, C - gray, F - purple. H - black.
The sources of electricity are two batteries 6 connected in series and a generator set 2 connected in parallel to the batteries.
The negative terminal of the batteries is connected to the vehicle ground via a remote-controlled ground switch 7.
The genset battery charging circuit is protected by a 3 x 60A fuse.
Relay 1 is introduced into the circuit, through which the excitation winding of the generator set is connected to the power source.
When starting the engine using an electric torch device, voltage is applied to relay coil 1, which opens all freely closed contacts and blocks the generator set for the period of operation of the electric torch device.
In addition, the circuit provides for blocking the disconnection of the mass of the batteries when the generator is running, since otherwise, when the batteries are disconnected, the generator set may fail.
For this, button 8 of the remote ground switch is connected to the power source through the normally closed contacts of the relay of the heater electric motors.
When the instrument and starter switch 13 key is in the "0" position, button 8 is powered through the circuit: "+" batteries - starter terminals 5 - starter relay 4 - ammeter 10 - instrument and starter switch 13 - heater motor relay 9 - button 8 - switch winding 7 mass - "-" batteries.
When button 8 is pressed, switch 7 operates and connects or disconnects the "-" batteries with the vehicle ground.
When the instrument and starter switch key is turned to position "1" or "2", voltage is applied to relay coil 9, which opens its normally closed contacts and breaks the power supply circuit of the remote ground switch-off button.
The mass switch VK 860-V is installed on the front bracket of the battery box and consists of an electromagnet, a housing with a contact part and a manual switch device with a protective cover (Fig. 2).
Disconnecting the batteries with button 8 is possible only when the instrument and starter switch key is turned to the “O” position, i.e. when the generator set is disconnected from the electrical system.