Tech Thursday: Westinghouse Recording KVA Demand Meter (Type RI-3)

Westinghouse Recording KVA Demand Meter (Type RI-3)

This object is a part of a line of Kva meters produced by Westinghouse in the early 1950s. Other types included the RI-2, RI-4, RI-6, RI-7, RI-8, RI-9, RI-10, RI-32, and RI-38. I’m afraid I couldn’t find anything out about its provenance. There are no Rice property tags, but if it was used at Rice, it was probably used in the Electrical Engineering department.

What I can tell you I learned from the manual, helpfully preserved and provided by www.electricalpartmanuals.com.

Kilovar Hours

Kilovolt Ampere Hours and Kilowatt Hours

The meters pictured above give readings of Kwh, Kvarh, and Kvah, and the chart (below) records Kw and Kva demand and power factor.

Chart recorder

What does that all mean? ‘Demand’ is the amount of electricity being used in a circuit at any given time, which can be tracked over time by the chart. ‘Power factor’ is a bit more complicated, and I will refer curious readers to Wikipedia for a better explanation that I can provide here. Basically, the demand meter can measure the power and work being done in a circuit at a given time and can record the demand for electricity over time. It can gather this information by being plugged into the circuit of interest.

Lines in (external)

Lines in (internal)

To load (external)

The mechanics are pretty wonderful to see up close, but the device has seen better days. The wires show signs of corrosion and the smell of burnt rubber when I removed the covering was quite pungent.