Padmount Transformer - A transformer designed for mounting on a concrete pad with underground connecting cables.

Panelboard - An assembly of buses and connections, overcurrent devices and control apparatus with or without switches, or other equipment constructed for installation as a complete unit in a cabinet.

Panelboard, Enclosed - An assembly of buses and connections, overcurrent devices and control apparatus with or without switches, or other equipment installed in a cabinet.

Park Model Trailer - a recreational vehicle unit that meets the following criteria:

• it is built on a single chassis mounted on wheels;
• it is designed to facilitate relocation from time to time;
• it is designed as living quarters for seasonal camping and may be connected to those utilities necessary for operation of installed fixtures and appliances; and
• it has a gross floor area, including lofts, not exceeding 50 m² when in the set-up mode, and having a width greater than 2.6 m in the transit mode.

Part-Winding Start Motor - A motor arranged for starting by first energizing part of its primary winding and, subsequently, energizing the remainder of this winding in one or more steps, both parts then carrying current.

Peak Demand - The maximum integrated demand during a time period.

Peak Line Current - Maximum instantaneous current during a cycle.

Percent IR (%IR) - The voltage drop due to conductor resistance at rated current expressed in percent of rated voltage.

Percent IX (%IX) - The voltages drop due to reactance at rated current expressed in percent of rated voltage.

Percent IZ (%IZ) - The voltage drop due to impedance at rated current expressed in percent of rated voltage.

Periodic Duty - see definition for Duty.

Permanently Connected Equipment - Equipment that is electrically connected to the supply by means of connectors that can be accessed, loosened, or tightened only with the aid of a tool.

Permit - The official written permission of the inspection department, on a form provided for the purpose, authorizing work to be commenced on any electrical installation.

Phase - Classification of an ac circuit usually single-phase, two wire or three wire; two-phase, three wire or four wire; or three-phase, three wire or four wire.

Photovoltaic - see definition for Solar Photovoltaic Systems

Plenum - A chamber associated with air-handling apparatus for distributing the processed air from the apparatus (supply plenum) to the supply ducts or for receiving air to be processed by the apparatus (return plenum).

Pools, Tubs, and Spas -

Special terminology and types:

Decorative Pool - a pool that could be used as a wading pool, that is larger than 1.5 m in any dimension, and that is readily accessible to the public.

Dry-niche Luminaire - a luminaire intended for installation in the wall of the pool in a niche that is sealed against the entry of pool water by a fixed lens.

Forming Shell - a structure intended for mounting in a pool structure to support a wet-niche luminaire assembly.

Hydromassage Bathtub - a permanently installed bathtub having an integral or remote water pump or air blower, and having a fill and drain water system, and includes therapeutic pools.

Leakage Current Collector - a device designed to provide a path to ground for leakage current originating from devices in contact with pool water.

Permanently Installed Swimming Pool - a pool constructed in such a manner that it cannot be disassembled for storage.

Spa or Hot Tub - a pool or tub designed for the immersion of persons in heated water circulated in a closed system incorporating a filter, heater, pump, and with or without a motor-driven blower but not intended to be filled and drained with each use.

Storable Swimming Pool - a pool constructed in such a manner that it may be readily disassembled for storage and reassembled to its original integrity.

Wet-niche Luminaire - a luminaire intended for installation in a forming shell mounted in a pool structure where the luminaire will be completely surrounded by pool water.

Portable as Applied to Electrical Equipment - The equipment is specifically designed not to be used in a fixed position and receives current through the medium of a flexible cord or cable and usually an attachment plug.

Portable Ground Fault Circuit Interrupter - A ground fault circuit interrupter which is either of the direct plug-in type or specifically designed to receive current by means of a flexible cord or cable and an attachment plug and which incorporates one or more receptacles for the connection of equipment which is provided with a flexible cord or cable and an attachment plug.

Power Fuse - A power fuse (expulsion and current-limiting) has high voltage ratings of 2.8-167 kV and x/r ratios of 15-25.

Power Follow Current - Refer to Follow Current.

Power-Frequency Withstand Voltage - A specified rms test voltage at power frequency that will not cause a disruptive discharge.

Power Outage - An interruption of power.

Power Supply Cord - An assembly consisting of a suitable length of flexible cord or power supply cable provided with an attachment plug at one end.

Primary Taps - Taps added in the primary winding (see definition for Tap).

Primary Voltage Rating - Designates the input circuit voltage for which the primary winding is designed.

Primary Winding - A winding connected to the voltage source or input.

Propane Dispensing and Storage (see also Hazardous Locations) - locations where propane is dispensed or transferred to the fuel tanks of self-propelled vehicles or to portable containers and to locations where propane is stored or transferred from rail cars or tanker vehicles to storage containers.

Special terminology:

Container Refill Centre - a facility such as a propane service station that is open to the public and where propane is dispensed into containers or the fuel tanks of motor vehicles and that consists of propane storage containers, piping, and pertinent equipment including pumps and dispensing devices.

Filling Plant - a facility such as a bulk propane plant, the primary purpose of which is the distribution of propane, that receives propane in tank car or truck transport for storage and/or distribution in portable containers or tank trucks, that has bulk storage, and that usually has container filling and truck loading facilities on the premises.

Propane - any material that is composed predominantly of the following hydrocarbons either by themselves or as mixtures: propane, propylene, butane (normal butane or iso-butane), and butylene.

Protected as Applied Mainly to Electrical Equipment - The equipment is constructed so that the electrical parts are protected against damage from foreign objects entering its enclosure.

Puncture - Term used when a disruptive discharge occurs through a solid dielectric. A disruptive discharge in a solid dielectric produces a permanent loss of dielectric strength; in a liquid of gaseous dielectric, the loss may be only temporary.

PVC Conduit - see definition for Conduit.

Qualified Person - One familiar with the construction and operation of the apparatus and the hazards involved.