P · Glossary
Polarity
Also known as Correct polarity, Polarity check, Reverse polarity
Polarity identifies whether conductors or terminals are connected in the expected live, neutral, positive or negative relationship.
Polarity is the relationship between conductors or terminals that shows which side is live or neutral in an AC circuit, or positive or negative in a DC circuit. In home energy documents it can appear as a polarity test on Electrical Installation Certificates, EICR (Electrical Installation Condition Report) forms and circuit schedules, and as a polarity check on solar PV string test records. It matters because reversed or incorrect polarity can mean equipment is connected differently from the labels, drawings or terminals expect.
Category
Electrical fundamentals
Applies to
Solar, Battery storage, EV charging, Heat pumps & AC
Last reviewed
13 Jun 2026