Bus MAZ-206, MAZ-226. Guide - part 75

MAZ fuse box

The MAZ fuse box is a device that houses safety elements designed to prevent damage to electrical devices and equipment.

The MAZ safety panel includes three modules:

1. In the first block, in accordance with the layout, there are fuses for 30 and 60 amperes. These elements are designed to protect generator sets and batteries from overvoltage and short circuits. The main component of the 60 amp relay box powers almost all electrical loads, except for the light alarm, since it is connected directly to the battery.
2. The second fuse box contains 21 6 amp devices.
3. The third module contains 9 8-amp components and one 16-amp component.

On the module itself there is a protective cover, on which information with labels is applied. The latter explain the purpose of safety devices and relays and indicate the resistance rating of the parts. All elements differ in appearance and location, but they are all designed to ensure the correct operation of the vehicle's electrical circuit. If voltage surges occur in the network, the fuse is the first to break, protecting electrical equipment from failure.

Only these components can operate without fuses:

• starter relay;
• main light switch;
• ground disconnect winding;
• mechanism for deactivating devices and automatic starting.

Marking and description of safety elements located in the second module:

• 127 – device responsible for protecting the speedometer, speed control mechanism;
• 57 – brake lights;
• 90 – windshield washing and cleaning systems;
• 120 – wheel and axle locking mechanism, reversing lights and optical hitch lighting devices;
• 162 – heating system for side rear-view mirrors;
• P61 – fuse responsible for the operation of the instrument lighting system;
• 55 – anti-fog optics protection device;
• 52 – side optics installed on the right and left of the car;
• 56 – left and right low-beam headlights;
• 53 – safety element for additional high-beam headlights;
• 54 (marked K and Z) – high beam headlights installed on the right and left, respectively;
• 78 – vehicle turning lights;
• 79 – light signaling of the vehicle;
• 80 – heating system fan;
• 31 – light indicators of the instrument cluster and control indicator;
• 50 – rear fog optics.

Also in this part of the module there are 11 relays:

• 1 – steering horn and sound signals;
• 2 – reversing lights;
• 3 – blocking of grounding disconnection;
• 4 – brake light lamps;
• 5 – relay responsible for the operation of the on-board control system;
• 6 – low beam optics;
• 7 – high beam blocking system;
• 8 – side lights;
• 9 – high beam;
• 10 and 11 – electric torch elements.

The third part of the module is marked PR112 and includes ten elements:

• valve – safety device for the cooling system fan clutch;
• 59 – element of the cabin lighting system;
• 131 – fuse responsible for the refrigerator, pneumatic signal, socket of an emergency light bulb;
• 133 – air dryer;
• 161 – safety component of the engine stop valve;
• 171 – timer and car radio fuses;
• 172 – element responsible for the operation of the body lighting system;
• 179 – malfunction of the fuel heating system;
• One slot in the module is reserved.

7.3. Power supply system (generator). Device.

electrical system consists of two sources: batteries and an alternating current generator set. In addition, the system includes a number of intermediate relays, a battery mass switch and a key switch for instruments and starter. The connection diagram for power supply system products is shown in Fig. 135

.

The generating set (GU) G273A is an alternating current generator with a built-in rectifier unit and an integrated voltage regulator (IVR). The technical characteristics of the generator set are given in Table 16.1. The generator (Fig. 136) is a three-phase synchronous electrical machine with electromagnetic excitation and is one of the power sources for electrical equipment. Equipped with a rectifier unit and an integrated voltage regulator. The small-sized integrated voltage regulator YA120M serves to maintain the voltage generated by the generator within specified limits. The regulator is an electronic device, closed with a lid and filled with a special sealant. The regulator has 4 pins. Using these leads, the regulator is installed in the brush holder so that the leads marked with the letters “W”, “D”, “B”, and “P” lie on the current-carrying busbars of the brush holder (Fig. 137). The brush holder also contains a 75 Ohm feed resistance 3, which serves to ensure reliable excitation of the generator set at low engine speeds. The electrical diagram for connecting the generator with the voltage regulator is shown in Fig. 138.

Source

AUTOPRIBOR

LLC NPK AVTOPRIBOR is Russia's largest manufacturer of electrical equipment and instruments for domestic cars, buses, tractors, combines, motorcycles and other equipment, supplying products to automobile factories and many consumers in the Russian Federation, the CIS and countries near and far abroad.

• Electric motors
• Speedometers
• Signposts
• Sensors
• Switches and relays
• Windshield wiper systems (wiper blades, wiper arms, wiper trapezes, wiper drives)
• Instrument clusters and panels
• Drive, brushes, levers
• Tachometers
• as well as products for household and industrial use.

In warehouses: 73 pcs.

Checking the voltage regulator

The regulator is designed to stabilize the generated voltage before supplying it to the vehicle's on-board circuit, including the battery for recharging it. The only way to determine its serviceability yourself is to check the charging of the generator, or rather, the amount of voltage it supplies to the battery terminals. Depending on the make and model of the machine, it can range from 13.5 to 15.5 V. Therefore, before checking the operation of the generator to ensure that the regulator is working properly, you need to find out exactly what voltage it should produce. This information can be obtained from the vehicle's owner's manual.

How to test a generator with a multimeter? To do this, switch the device to voltmeter mode and, observing polarity, connect its probes to the battery terminals with the engine not running. A voltage between 12-12.8 V is considered normal. Next, start the engine and repeat the procedure. The voltage at the battery terminals should increase to 13.5-15.5 V. Only in this case can the regulator be considered operational. An increase or decrease in voltage, on the contrary, indicates that it is faulty.

How to check the generator for the operability of the stator windings

Let's move on to the stator. It has several windings, each of which must be checked separately. But before this, you must definitely disconnect the wires connecting the terminals of the windings and the diode bridge.

We connect the probes of the multimeter, switched on in ohmmeter mode, to the terminals of each of the windings in turn. The working winding should have a resistance of about 0.2 Ohm.

Next, you need to measure the resistance between the common terminal (zero) of the stator and the terminal of any of the windings. It should be at least 0.3 Ohm.

Repair and connection of the generator on MAZ trucks

The MAZ generator is a source of electricity for the vehicle's on-board network when the engine is running. The consumers are powered in parallel with the battery. The network is designed in such a way that when the generator voltage is more than 24 V, the batteries begin to charge, and less - vice versa. MAZ vehicles are equipped with units of various types, differing in power and connection method. However, their design and operating principle are the same.

AUTOPRIBOR

LLC NPK AVTOPRIBOR is Russia's largest manufacturer of electrical equipment and instruments for domestic cars, buses, tractors, combines, motorcycles and other equipment, supplying products to automobile factories and many consumers in the Russian Federation, the CIS and countries near and far abroad.

• Electric motors
• Speedometers
• Signposts
• Sensors
• Switches and relays
• Windshield wiper systems (wiper blades, wiper arms, wiper trapezes, wiper drives)
• Instrument clusters and panels
• Drive, brushes, levers
• Tachometers
• as well as products for household and industrial use.

In warehouses: 73 pcs.

Not available:

How to check the generator for performance? Self-check and repair of the generator

A generator is a kind of power plant that provides energy to all engine systems: power, cooling, ignition, so its failure will inevitably lead to other malfunctions. To prevent breakdowns, it is necessary to systematically diagnose it, and if problems cannot be avoided, repair it immediately.

In this article we will talk about how to check the generator for performance without resorting to the help of specialists. But first, let's look at the symptoms of its possible malfunctions.