Electrical Metering Standards and Requirements in Indiana

Electrical metering in Indiana governs how electricity consumption is measured, billed, and verified across residential, commercial, and industrial service points. Metering standards determine meter type, installation method, accuracy tolerances, and the division of responsibility between utilities and customers. The Indiana Utility Regulatory Commission (IURC) and Indiana's adopted edition of the National Electrical Code (NEC) together establish the regulatory framework within which utilities, electrical contractors, and property owners operate.

Definition and scope

Electrical metering encompasses the instruments, enclosures, wiring configurations, and measurement protocols used to quantify electrical energy delivered to a premises. In Indiana, metering standards operate at two intersecting levels: utility-facing accuracy and tariff rules administered by the Indiana Utility Regulatory Commission, and electrical installation standards derived from the NEC as adopted by the state.

The IURC holds authority over investor-owned utilities operating in Indiana — including Duke Energy Indiana, AES Indiana (formerly Indianapolis Power & Light), Northern Indiana Public Service Company (NIPSCO), and Vectren Energy Delivery (now CenterPoint Energy Indiana). Each of these utilities files tariffs and metering standards with the IURC, which must approve them before they govern customer-utility relationships. Rural electric membership corporations (REMCs) operate under cooperative governance structures and are subject to both IURC oversight and their own member-approved service rules.

Metering installations on the customer side of the service point — meter bases, enclosures, and conductor termination — fall under NEC Article 230 (Services) and Article 240 (Overcurrent Protection), as applied through Indiana's state electrical inspection program administered by the Indiana Department of Fire and Building Services (DFBS). The broader regulatory context for Indiana electrical systems defines how these two regulatory layers interact.

This page addresses metering standards applicable within Indiana state boundaries. Federal regulatory instruments — such as FERC-approved tariffs for wholesale transactions — are not covered here. Interstate transmission metering and NERC reliability standards fall outside the scope of this reference.

How it works

Indiana metering installations follow a structured sequence from utility specification through customer installation to utility acceptance and sealing.

1. Utility specification issuance. Each utility publishes a metering specification document, sometimes called a "service entrance guide" or "electric service requirements" manual. These documents define acceptable meter base configurations, wire entry points, conduit sizing, and ground clearance requirements. Duke Energy Indiana, for example, publishes its Electric Service Requirements manual, which specifies meter base ampere ratings, jaw configurations, and bypass provisions.

2. Meter base installation by licensed contractor. The customer is responsible for installing the meter base and associated service entrance equipment. In Indiana, this work must be performed by a licensed electrical contractor under Indiana electrical contractor requirements. The meter base must match the utility's socket type — typically the 4-jaw or 7-jaw ring-type base conforming to ANSI C12.10 (Physical Aspects of Watthour Meters).

3. Electrical inspection. Before the utility will set a meter, the installation must pass inspection by the authority having jurisdiction (AHJ). For residential construction, this is typically the DFBS or a locally authorized inspection program. The Indiana electrical inspection process outlines how inspection requests are submitted and resolved.

4. Meter set by utility. After a passing inspection and utility release authorization, the utility installs and seals the revenue-grade meter. The meter seal is the legal demarcation — tampering with a sealed meter constitutes a criminal offense under Indiana Code § 35-43-4 in addition to civil liability under utility tariff provisions.

5. Ongoing accuracy testing. Utilities are required under IURC rules to test meters on a defined schedule and to respond to customer-initiated accuracy complaints within prescribed timeframes. Accuracy tolerances for revenue-grade watthour meters in the United States are governed by ANSI C12.20, which specifies a Class 0.2 accuracy standard (±0.2%) for revenue metering.

Meter types by service class:

Common scenarios

Residential new construction. A single-family home receives a 200-ampere, 120/240V single-phase service. The electrical contractor installs an outdoor meter base conforming to the serving utility's specification for a 4-jaw, 200A ringless socket. After DFBS inspection approval and utility service authorization, the utility sets an ANSI-standard solid-state watthour meter. Details on residential service configurations appear in residential electrical systems Indiana.

Commercial multi-tenant metering. A strip mall with 8 tenant spaces requires individual revenue-grade meters for each unit plus a master meter for common-area lighting. This configuration — called a "master-metered with sub-metered" arrangement — requires that all revenue meters be utility-grade ANSI C12.20 devices if the sub-metering results in direct billing to tenants. Indiana law does not permit landlords to mark up electricity resold to tenants beyond the utility rate without specific IURC authority. Multi-family metering configurations are addressed in indiana multi-family electrical systems.

CT-rated metering for industrial loads. A manufacturing facility operating at 480V three-phase with a 1,200-ampere service requires current-transformer (CT) rated metering, because direct-connected meters are not rated above 320 amperes. In CT metering, instrument-grade current transformers — typically 600:5 or 1200:5 ratio — step down the load current to a measurable secondary current, which the revenue meter reads and multiplies by the CT ratio. NIPSCO and Duke Energy Indiana both publish CT ratio requirements and wiring diagrams in their service manuals. Industrial metering scenarios intersect with indiana electrical load calculations when service upgrades are evaluated.

Net metering for solar installations. Indiana customers with grid-tied solar photovoltaic systems are entitled to net metering under Indiana Code § 8-1-40 (Indiana General Assembly), which requires utilities to install bidirectional meters capable of recording both imported and exported energy. The transition from a standard meter to a bidirectional or interval meter is a utility function coordinated through the interconnection application process. The Indiana solar and renewable electrical systems reference covers interconnection requirements in detail.

EV charging with demand metering. Properties installing DC fast-charging stations — which may draw 50 kW to 350 kW per unit — trigger demand metering requirements, because utilities assess demand charges (in $/kW) separately from energy charges (in $/kWh) for commercial accounts above a defined threshold. NIPSCO's commercial rate schedules, for example, apply demand charges to accounts exceeding 50 kW of measured peak demand. Indiana EV charging electrical requirements addresses the electrical service sizing that accompanies demand metering transitions.

Decision boundaries

The central determination in any metering situation is who holds responsibility for each component and under which standard it must comply.

Utility property vs. customer property. The meter itself is always utility property, sealed by the utility, and governed by the utility's IURC-approved tariff. The meter base, weatherhead, service entrance conductors, and main disconnect are customer property, installed under NEC and DFBS jurisdiction. The dividing point is the load-side terminal of the utility meter — everything downstream of that point is customer equipment.

Direct-connected vs. CT-rated thresholds. Services up to 200 amperes at 120/240V single-phase typically use direct-connected meters. Services above 200 amperes — and virtually all three-phase services in commercial and industrial settings — require CT-rated metering. The specific threshold at which a utility mandates CT metering varies by utility tariff; contractors should consult the serving utility's service entrance manual before specifying meter equipment.

Revenue metering vs. sub-metering. Revenue meters (used for utility billing) must conform to ANSI C12.20 accuracy standards and are set and sealed by the utility. Sub-meters (used for internal cost allocation by a building owner) are not subject to IURC tariff requirements but are subject to standards under Indiana's weights and measures law if used to bill tenants directly. The distinction determines whether utility involvement in meter installation is mandatory.

Permitting applicability. New meter base installations, replacements, and service entrance modifications all require electrical permits in Indiana. Routine meter exchanges by the utility — replacing one revenue meter with another of the same configuration — do not require a customer permit, but any change to the meter base, socket, or service entrance conductors does. The indiana electrical panel standards reference addresses the service entrance equipment that accompanies metering installations.

Professionals navigating metering-related service questions can locate additional sector context through the Indiana Electrical Authority index, which maps the full scope of regulated electrical topics across the state.

References

• Indiana Utility Regulatory Commission (IURC)

• Indiana Department of Homeland Security — Fire and Building Safety (DFBS)