Question, someone help please!

With regards to centre-zero ammeter, if it is reading only Zero (deflection on the centre), what does that mean? And what impact does it has on alternator and battery?

I understand that...
• If the deflection reads negative (-ve), it indicates that alternator has failed and the battery is working.
• If the deflection reads high positive (+ve), it indicates that the battery is at fault and is not accepting or holding its charge but the alternator is working.

Hello,
A zero indication of a Centre-zero ammeter means that the charge coming from the alternator is matching the electrical depends of the aircraft. This is normal operation for the electrical alternator system.
Think of it this way. During moments of high demand the battery will step in to help until the alternator can catch up. This is where you will see a discharge usually in the form of a quick flick to the negative side. The alternator then repays the battery for its help by topping its charge by showing a postive charge then returning to zero once the battery is back up to capacity.

A high positive reading may be the result of two things. A faulty battery, or, a faulty voltage regulator.

Don't forget the important role of the voltage regulator. The voltage regulator is there to regulate the output from the alternator. If it fails, the alternator can become a simple generator and will start pumping more voltage into the electrical system including the battery. More than the system can handle and could cause an electric fire. It could also make the battery overheat or explode.

Turning the alternator switch off then on can reset most systems. Check P.O.H your aircraft for the correct procedure.

Hope this helps,

Mister W.

Thank you so much Mister W! Your explaination has help me to understand it a lot more. I really do appreciate your help!

No worries. Glad to be of help.