Precautions for the use of Genset Voltage Transformer

What is voltage transformer of diesel genset?

The voltage transformer is used to change the voltage on the line. The purpose of voltage transformation of voltage transformer is mainly to supply power to measuring instruments and relay protection devices, to measure the voltage, power and electric energy of the line, or to protect valuable equipment, motors and transformers in the line in case of line failure. Therefore, the capacity of voltage transformer is very small, generally only a few volt ampere or dozens of volt ampere, The maximum shall not exceed 1000 VA.

There are more than one type of diesel genset transformer, which can be divided into voltage and current transformers and so on. This is because the transformer is usually only used for the supply of voltage and current. For the voltage transformer, its main function is to supply voltage to the coil, and so is the current transformer.

The following points shall be paid attention to when using the voltage transformer of diesel generator set.

1.The working voltage of the voltage transformer shall be equal to or less than the rated voltage of the transformer.

2.The rated capacity of voltage transformer shall be greater than the large capacity of load to ensure its corresponding accuracy. The watt hour meter used for cost calculation shall adopt voltage transformer with accuracy of class 0.5.

Voltage transformers with accuracy of class 1 shall be used for general measuring instruments and relays, and voltage transformers with accuracy of class 3 can be used for measuring instruments (such as voltmeters) used to estimate measured values.

3.The wiring of voltage transformer, relay and measuring instrument shall pay attention to phase difference and polarity to make the reading of measuring instrument and relay protection action accurate.

4.Each voltage coil of the secondary load of the voltage transformer shall be connected in parallel, and the secondary winding of the voltage transformer shall not be short circuited.

5.For the auxiliary wiring of voltage transformer, for the small generator set with ungrounded neutral point, in order to save one mutual inductor, V-V wiring mode can be generally adopted. If the secondary side of the voltage transformer is required to adopt phase B grounding in the same period, when the fuse of the secondary side of the voltage transformer is blown, the secondary winding of the voltage transformer will lose phase B grounding point. In order to realize protective grounding, a breakdown protector shall be installed at the neutral point of the compound.

Function of oil outlet valve of diesel generator set

1. The oil outlet valve separates the plunger chamber from the high-pressure oil pipe when there is no oil supply, so as to prevent the fuel of the high-pressure oil pipe from being sucked back to the oil pump chamber when the plunger goes down.

2. The oil outlet valve of diesel generator set controls the residual pressure maintained in the high-pressure oil pipe, so that the fuel pressure in the high-pressure oil pipe can rise quickly during the next fuel injection.

3. The oil outlet valve can quickly reduce the oil pressure in the high-pressure oil pipe when the oil supply of the fuel injection pump is completed, so as to ensure that the oil cut-off is crisp and clean and eliminate the oil dripping phenomenon of the fuel injector.

Whether in AC generator or DC generator, there will be motor transformer. When we use transformer, we must know the connection method of ammeter, voltmeter and watt hour meter.

In addition, please note that in order to install the generator and transformer safely, we need to ground the transformer during installation, otherwise instantaneous strong high voltage may be generated, which is not conducive to our personal safety. For the auxiliary wiring of voltage transformer, for small generator sets with ungrounded neutral point, in order to save one mutual inductor, V-V wiring mode can be generally adopted. If the secondary side of the voltage transformer is required to adopt phase B grounding in the same period, when the fuse of the secondary side of the voltage transformer is blown, the secondary winding of the voltage transformer will lose phase B grounding point. In order to realize protective grounding, a breakdown protector shall be installed at the neutral point of the compound. Moreover, the transformer shall not be open circuit or short circuit at the limit.