46, So-called three-phase four cables what happened?

Answer: The cable of generator set has 4 pieces, three pieces among them is fire cable, one is zero cable. The voltage is 380v between one pc fire cable the other fire cable; the voltage is 220v between fire cable and zero cable.

47, Three-phase short-circuit is what happened? What is the matter with it?

Answer: the fire cable been not haven yet any burden, directly short-circuit is called three-phase short-circuit. It is very terrible, even more let machine broken and people dead.

48, So-called send an electricity on the contrary is how happened? which two kinds of severity results will be happened?

Answer: The self-provided generator sends the electricity to the city net which call sending electricity on the contrary, the severity results have two kinds :

• The city net had a power fail, its city net power and self-provided generator power produce a non- same period combination, it must destroy the genset. If the capacity of self-provided generator is too lot, it can also let the city net shock.

• b) If the city net having a power fail to be maintaining, its self-provided generator sending electricity on the contrary. It will make the maintained- people at supplied-electrical department dead by the electricity ?

49, Why does the research people must check all the stud bolts in genset is in order or not before trying machine? It is all circuits connect intact or not?

Answer: After long time transport, it is sometimes made screw bolts and the circuit connect loosen or lost, which will influence trying a little or let the machine broken more.

50, The electric power belongs to which kind of energy? What is the character of the alternate current?

Answer: The electric power belongs to second class energy, the alternate current is converted by the machine, the direct current is converted by the chemistry, the characteristics of the alternate current is not be stored, generating electricity must be using on time.

55, What does "two three system" of the electric power system concretely mean?

Answer: Two tickets mean the work ticket and the operation ticket, that is any work and operation in electricity facility. Firstly, the people must obtain work ticket and operation ticket signed by Representative director on duty, who must perdue it according to the ticket.

Three system mean shift-duty system and returned-check system, equipments to periodically cut over system.

56, when the first set practical type the diesel engine was born in whole world, what place, who be the inventory person? How about the condition at present?

Answer: the first set diesel engine was born in the Augsburg of Germany in 1897, it was discovered by the people named Rudolf Dieselin the MAN company. At present, the english name for diesel generator use the people name.