Preparing a useful utility capacity inquiry

A useful preliminary inquiry identifies the site, the proposed load and when service is needed. It also explains how that load will operate. These inputs give the utility a basis for assessing the request and identifying the further information or analysis required.

National Grid's New York September 2024 service delivery process requests location, load and approximate service date at Step Zero. Massachusetts' service-connection guidance similarly identifies location, peak load and timing as the inputs for an initial assessment. Follow the serving utility's process; the term “Step Zero” is not universal.

Describe the load the utility will need to serve

Connected load is the sum of the installed equipment's electrical input ratings. Expected peak demand estimates the greatest simultaneous draw. Equipment may cycle, operate in different shifts or peak in different seasons, so the two figures can differ materially. Explain the assumptions behind the expected peak rather than entering identical totals by default.

National Grid's load sheet requests connected and diversified load separately, but does not define the latter field. In general, diversification accounts for equipment not reaching maximum demand simultaneously. Confirm the utility's intended calculation rather than assuming that its field is identical to another utility's peak-demand estimate.

Break the estimate down by equipment type and seasonal use. Lighting, heating, process loads and charging can affect the supply at different times. Explain which loads are expected to operate together and how that assumption produces the proposed peak.

Identify significant motors and starting characteristics, as well as storage, generation and any requested alternate supply. Brief starting currents and power-quality effects need separate consideration from an average demand estimate. National Grid's load sheet, for example, requests a motor data sheet for new three-phase motors above 15 HP and single-phase motors above 5 HP; those are requirements of that form, not a universal threshold.

Separate an inquiry from an application package

A preliminary inquiry can begin with the core project information. A formal application requires the serving utility's documents and technical detail. Prepare available plans, but do not assume every document needed for construction must be complete before making initial contact.

National Grid's New York process moves from an initial inquiry to a work request with a load sheet, one-line diagram and additional documents where needed. Central Hudson's service delivery process lists a stamped, municipally approved site plan, an application, a load letter and a one-line diagram. The latter document is undated; confirm the current requirements for the specific project.

A one-line diagram shows the proposed electrical arrangement. A load schedule explains what equipment will operate and when. An electrical professional can prepare these and reconcile the project totals with the utility's forms. See load forms and load letters for the document distinction.

A concise inquiry template

Subject: Capacity inquiry — [street address, town] — [expected additional peak demand] kW

• Location: address, parcel identifier and details of any existing utility service.
• Project: proposed use, whether this is new service or an expansion, and who is making the request on whose behalf.
• Load: expected additional peak demand, existing demand where known, connected load and the assumptions used to estimate simultaneous operation. Include service voltage and phase if known.
• Operating profile: hours, seasonal variation, significant motors and starting behavior, storage, generation and any redundant-feed requirement.
• Timing: requested service date and cumulative load by date if the project will expand in stages.
• Available documents: site plan, load schedule and one-line diagram, identifying any items still being developed.
• Requested next step: confirm the serving equipment, the appropriate application route and what further information is needed.
• Contacts: the project representative and the person responsible for technical questions.

Keep the initial request specific about uncertainties. A preliminary load estimate can be useful if identified as such; an unexplained precision can be misleading. When the response arrives, assess what it establishes and what remains unresolved before using it in a site decision.