Why is the armature reaction in an alternator called the pessimistic method?
At lagging loads, armature reaction in an alternator is 6. Synchronous impedance method of finding voltage regulation of an alternator is called pessimistic method because A. it was first suggested by Dr. Pessimist of Depression Island in Indian ocean.
How is the magnetic pole of an alternator excited?
Nand Spoles fixed to its outer rim. The magnetic poles are excited (or magnetised) from direct current supplied by a d.c. source at 125 to 600 volts. In most cases, necessary exciting (or magnetising) current is obtained from a small d.c. shunt generator which is belted or mounted on the shaft of the alternator itself.
What happens when two alternators are in synchronization?
When two alternator are operating in parallel and at perfect synchronization, their synchronizing power will be (A) negative. (B) infinite. (C) positive. (D) zero.
What are slip rings and commutator in an alternator?
As the exciting voltage is relatively small, the slip-rings and brush gear are of light construction. Recently, brushless excitation systems have been developed in which a 3-phase a.c. exciter and a group of rectifiers supply d.c. to the alternator. Hence, brushes, slip-rings and commutator are eliminated.
Can a battery voltage test be done on an alternator?
One test is not enough if you are diagnosing a charging system problem. All too often, the alternator is condemned as the source of the problem if only battery voltage is present with the engine running. If this is the case, it only means that the alternator is not charging, but does not reveal why.
Is it normal for an alternator to not charge?
Still, it’s perfectly normal for others to see the alternator not charge at all intermittently. One test is not enough if you are diagnosing a charging system problem. All too often, the alternator is condemned as the source of the problem if only battery voltage is present with the engine running.
Is the armature reaction completely magnetizing in an alternator?
In an alternator, the armature reaction will be completely magnetizing in case the load power factor is 15. In a star connected armature winding Answer: (a) phase voltage contains 3rd harmonic e.m.f. but line voltage does not contain it. 16. The slip rings employed in a 3-phase alternator in hydro station are insulated for 17.
When does the alternator light turn on the battery?
On older vehicles, the battery light would turn on the alternator light when the alternator output or battery voltage dropped below a preset value. The battery light on modern vehicles, however, is controlled by data and trouble codes. This is why a scan tool is essential to diagnosing a charging system.