Definition
Electrical circuitry in a multi-engine airplane that automatically balances the electrical output of two or more alternators or generators so each unit carries an approximately equal share of the total electrical load on the airplane's bus.
Plain English
A built-in system that makes sure two power sources working at the same time share the workload evenly, instead of one doing most of the work while the other coasts.
Context Anchor
You encounter this term in discussions of multiengine aircraft electrical systems, especially when more than one alternator or generator can power the same equipment.
Derivation
"Paralleling" comes from the electrical term parallel, meaning two power sources connected so they feed the same circuit at the same time. The circuitry's job is to keep those parallel sources working together cleanly.
Why Pilots Care
Without proper paralleling, one unit can overload while the other idles, leading to voltage instability or loss of electrical power.
Analogy
It is like two people carrying one heavy box. The paralleling circuitry helps make sure both people carry their share instead of one person taking nearly all the weight.
Intuition Check
Paralleling does not mean simply turning on two power sources at once. Here it means controlling them so they can safely share the same electrical work.
Example Sentence 1
During the runup, the pilot checked that both alternator output gauges showed roughly equal current, confirming the paralleling circuitry was working.
Example Sentence 2
A fault in the paralleling circuitry caused one generator to carry the full load during cruise.