Phone Line & RTU Guidance for Distributed Generation
For distributed generation (DG) installations in National Grid's service territory in New England, DG customers are often required to procure dedicated services from the local telephone company. Please refer to the guidance below.
Phone Line for Revenue Meter
For any project above 60kW (AC), an analog / POTS (Plain Old Telephone Service) phone line to National Grid's revenue meter location shall be provided. The phone line must be capable of direct inward dial without human intervention or interference from other devices such as fax machines, etc. Please refer to the
National Grid Phone Line Installation Guide for the most up-to-date requirements. National Grid will connect the conduit to the meter socket and the telephone wire to the modem in the meter.
Remote Terminal Unit for Energy Management System
In order to fulfill this requirement, DG customers must contact the local telephone company to request the installation of an ordinary phone line service.
Note: This requirement will generally be identified during the initial screening review, and it is required as a result of ISO New England's
Operating Procedure No. 14 (OP14), which includes a data monitoring requirement for DG installations. Essentially, the only exceptions to this requirement include: (1) DG facilities with ≤60kWAC of aggregate generating capacity and (2) DG facilities that are only able to reduce load. In other words, any DG facility >60kWAC that back feeds to the grid (such as a Net Metered facility or a Qualifying Facility) is required to have a phone line installed!
For any project 1MW (AC) or larger (and on a case-by-case basis for smaller capacities), National Grid requires DG customers to install an Energy Management System (EMS) Remote Terminal Unit (RTU). This RTU must be able to communicate several types of status and control information, as described in
National Grid's ESB 756; however, generally the RTU inputs include:
- Status of individual generator breakers
- Status of main or interconnect breaker at the point of common coupling (PCC)
- Three phase line current for each generator
- Three phase line current at the PCC with the Company
- Three phase line-to-line voltage for each generator
- Three phase line-to-line voltage at the PCC with the Company
- Output kW for each unit (+ delivered to the Company, - received)
- Output kVAR for each unit (+ delivered to the Company, - received)
- Total MW (+ delivered, - received) at the PCC
- Total MVAR (+ delivered, - received) at the PCC
- Remote trip and block closing of the Customer's automated disconnect device designated by the Company
Note: The details of this requirement will generally be identified during the impact study, and National Grid will provide an EMS-RTU point list for inputs required at the DG facility. This requirement may alternatively be met by any suitable communications device that meets the
In order to fulfill this requirement, DG customers must contact the local telephone company to order a Multi-Protocol Label Switching (MPLS) line to communicate with "NGrid Muni VPN" (National Grid's Virtual Private Network). To order this service through Verizon, DG customers should contact Verizon Business and submit the
PIP (Personal Internet Protocol) order form
. Additionally, Verizon may require a "High Voltage Protection Study" as part of their installation process.
Note: National Grid advises that DG customers consult with Verizon regarding the timeframe for installing an MPLS line at their site. Previous experience has shown that these installations can take months (not just a few weeks) to complete, so please plan accordingly.
DG customers can reach out to Verizon Business by:
DG customers can click here to download a PIP order form
. In this form, National Grid has already included technical specifications in the comments, and the DG customer must fill in all information highlighted in red.
National Grid Phone Line Installation Guide: /non_html/Expedited%20Standard%20Interconnection/Phone%20Line%20Installation.pdf
ISO New England's OP14: http://www.iso-ne.com/rules_proceds/operating/isone/op14/op14_rto_final.pdf
National Grid's ESB 756: /non_html/shared_constr_esb756.pdf
Verizon's PIP Form (for NGRID-MUNI): /non_html/Verizon_PIP_form_NGRID-MUNI.xls
National Grid's Expedited/Standard Interconnection Documents Zip File: /non_html/Expedited%20Standard%20Interconnection.zip