During a routine preventive maintenance call, which measurement should be recorded on the service invoice?

• A. Temperature readings
• B. Pressure readings
• C. Volts and amps readings
• D. RPM readings

Answer: (C)

Recording electrical conditions is essential in routine preventive maintenance because it provides objective evidence that the system’s electrical components are operating within safe and expected limits. Volts and amps readings show the actual supply and how much current the equipment is drawing, which helps identify issues like loose connections, overloads, underloads, or faulty components before they cause a failure. While temperature, pressure, and RPM can indicate performance and condition, volts and amps are the most universally relevant measurements to document on a service invoice, as they reflect the electrical health of the entire system.