This standard stipulates the range of working voltage of motor vehicles and towed vehicles’ external lighting and signal devices, and the methods to measure these working voltages.
This standard is equivalent to the international standard ISO 3559-1976 Road vehicle - Working voltage of lamps fitted on motor vehicles and their trailers.
Working voltages and their measurement for lights and lighting signal devices fitted to motor vehicles and towed vehicles
1 Applicable scope
1.1 This standard is applicable to vehicles propelled by internal combustion engines and equipped with lead-acid batteries, and to their trailers.
1.2 The methods stipulated in this standard is for measuring:
a. The working voltage of the electrical connecting terminal of incandescent lamps in the external lighting and signal devices fitted on vehicles.
b. The working voltage on socket terminals of the electrical connectors fitted on the motor vehicles towing trailers?.
c. The working voltage of the incandescent bulb electrical connecting terminals in the external signal devices fitted on trailers.
2 Terms
2.1 Terms relating to filament lamps
2.1.1 Nominal voltage
voltage marked on the bulb or its package
2.1.2 Test voltage
voltage on the bulb to let the bulb reach the photoelectric parameters and the average life stipulated in the national standard or specialized (departmental) standard, the values are stipulated in the national standard or specialized (departmental) standard
2.1.3 Working voltage
actual voltage on the bulb’s electrical connecting terminal or on the electrical connector’s socket (or plug) lug
2.1.4 Working voltage range
value range of the working voltage stipulated in this standard, including the maximum and/or minimum value
2.2 Terms relating to a vehicle’s and trailer’s electrical system
2.2.1 Vehicle test voltage
actual voltage on the battery’s connecting side under the testing conditions stipulated in this standard
2.2.2 Trailer test voltage
actual voltage on the socket (plug) lug for testing when the electrical power is supplied by an external constant voltage power supply according to the requirements of this standard
2.3 Other terms
For other terms, please refer to GB 3730.1-83 Motor vehicles and trailers - Types - Terms and definitions, GB 4785-84 Numbers, positions and colours of the external lighting and light signalling devices for motor vehicles and their trailers, GB 3949-83 Laboratory d.c. resistors, and GB 5008.1-85 Lead-acid starter batteries - Part 1:Technical conditions and methods of test.
3 Measuring procedures
3.1 Preparation of vehicles and trailers
3.1.1 During all voltage measurements, equivalent resistors or calibrated filament lamps shall be used for the lamps to be measured to substitute for all those filament lamps installed. The method chosen shall be recorded in the test report. In case of dispute, the method using resistors shall be decisive.
The resistance of the equivalent resistor or the calibrated filament lamps must meet those specified in Table 1. If the type of the filament lamps is not included in Table 1, then its equivalent resistance shall be determined according to the average power consumption at its test voltage.
Table 1
Nominal value of filament lamps Equivalent resistance, Ω
(Limit of intrinsic error is ±3%) Type of filament lamps International type of filament lamps
12V 60/55W
24V 75/70W 2.52/2.75
8.3/8.9 LQ12-60/55P
LQ24-75/70P H4
12V 65W 2.77 LQ12-55-1
LQ12-55-2
LQ12-55-3 H1, H2 and H3
24V 70W 10.1 LQ24-70-1
LQ24-70-2
LQ24-70-3
12V 45/40W
24V 55/50W 3.35/3.77
11.3/12.4 QT12-45/40P
QT24-55/50P E (or R2)
12V 35W
24V 35W 5.21
22.4 - F2
12V 21W
24V 21W 7.3
28.0 QT12-21
QT24-21 P25-1
12V 21/5W
24V 21/5W 7.3/30.4
28.0/78.4 QT12-21/5
QT24-21/5 P25-2
12V 10W
24V 10W 18.2
62.75 QT12-10
QT24-10 R19/10
12V 5W 36.4 QT12-5
QT12-5 SV R19/5,C11 and W10/5
24V 5W 112.0 QT24-5
QT24-5 SV
12V 4W
24V 4W 45.5
157.0 - T8/4
12V 3W
24V 3W 60.8
196.0 - W10/3
3.1.2 Every equivalent resistor shall be connected to a plug for measuring accordant to the replaced bulb, and the resistance and working voltage of the equivalent resistor shall be measured at the connecting side of the plug for measuring (Figure 1).
Figure 1
3.1.3 For vehicles towing trailers fitted with electrical connector sockets, the equivalent resistor shall approximately simulate the typical load of a trailer, and its equivalent resistance shall meet those specified in Table 2. During the whole measuring process, the equivalent resistor shall be connected to the socket through electrical connector plug, except for the situations otherwise specified in 3.3.3. The equivalent resistance shall be measured on the plug’s lug, and the working voltage shall be measured on the socket’s lug (Figure 2).
Foreword i
1 Applicable scope
2 Terms
3 Measuring procedure
4 Measuring environment and apparatus and meters for measurement
5 Working voltage range
