Every fixed appliance in a Kansas house carries a data plate, and it contains the answers to most of the questions an electrician would otherwise have to ask. Very few homeowners have ever read one.

Where to find it

On the back, inside a door, under the unit, or on the side of an outdoor condenser.

Photograph it before the appliance goes against a wall. That is the last convenient moment, and the photograph answers questions for as long as you own the machine.

Voltage

Stated as 120, 240, or occasionally as a range such as 208 to 240.

That range matters. Commercial buildings frequently run 208 volts while houses run 240, and equipment rated for both will operate at reduced output on the lower figure.

A single number tells you which kind of circuit the appliance needs and therefore whether one already exists.

Amps

The current draw, and the figure most directly useful.

For simple resistive equipment this is the whole story: multiply by voltage to get watts, compare against the circuit.

Watts

Often given instead of amps, particularly on heating equipment.

Divide by voltage to get current. A 1,500-watt appliance on 120 volts draws 12.5 amps, which is most of a 15-amp circuit before anything else is connected.

Minimum circuit ampacity

This appears on motor-driven equipment, principally air conditioning and heat pumps.

It states the smallest conductor the equipment may be fed by, accounting for the motor’s characteristics. It is not the same as the running current and it is not the same as the breaker size.

Maximum overcurrent protection

The companion figure, stating the largest breaker or fuse permitted.

These two numbers do not match, and that surprises people. Motor circuits are permitted protection above the conductor’s ampacity, because the alternative is a breaker that trips every time the compressor starts.

Sizing from tonnage, from the old unit, or from what the existing wire happens to be is wrong. These two figures govern, and any HVAC installation in Wichita or the surrounding Sedgwick County area is inspected against them.

Locked rotor amps

The current the motor would draw if it were prevented from turning. It indicates the magnitude of the starting surge.

Relevant for generator sizing, because a generator has to supply that momentary demand rather than just the running current.

Running load amps

The steady draw under normal operation, distinct from the starting figure.

Service factor

A multiplier indicating how much beyond its rating a motor can be operated continuously. A figure above one means some margin exists.

Duty cycle

On equipment such as welders, stating what proportion of a period the machine may operate at its rated output. A machine rated at a given output for a fraction of each period cannot run continuously at that level.

Phase

Single or three. Three-phase equipment cannot be connected to a residential service without conversion, and this is the field that reveals whether a used industrial machine is usable at a given property.

Frequency

Sixty hertz in North America. Worth checking on imported equipment, since equipment designed for fifty hertz behaves differently.

Why this matters before buying

Three common outcomes come from not reading it.

An electric tankless water heater whose combined circuit requirement exceeds anything a typical Wichita house on a 100-amp service can supply.

A used three-phase machine tool at an attractive price on a property with single-phase service.

An induction cooktop drawing more than the radiant unit it replaces, on a circuit sized for the old one.

All three are discovered on delivery day, and all three were printed on a plate.

What to do with it

Keep the photographs somewhere retrievable, with the house records rather than on a phone that gets replaced.

When planning any addition, hand the figures to whoever is running the load calculation. Having Wichita electrical services work from nameplate data rather than assumptions produces a number you can rely on and frequently avoids a service upgrade that a rule-of-thumb estimate would have suggested.

Permits for circuits sized from those figures come from the Metro Area Building and Construction Department for Wichita and unincorporated Sedgwick County, on (316) 660-1840, with inspection against the 2023 code edition in force locally.

The one-line version

Before you buy it, photograph the plate. Before you install it, give the plate to the electrician.

Model and serial number

Also on the plate, and worth photographing for a reason unrelated to circuits.

Parts, manuals and recall notices are all indexed by model and serial. An

appliance that fails ten years in is much easier to source parts for when those

numbers are recorded somewhere other than on a plate behind the machine.

Manufacture date is frequently encoded in the serial number, which tells you how

old a unit inherited with a house actually is.

The plate is also where any listing marks appear, indicating the standards the

equipment was evaluated against.