Rhode Island Code of Regulations
Title 815 - Division of Public Utilities and Carriers
Chapter 30 - Electric Utilities
Subchapter 00 - General Administration
Part 1 - Standards for Electric Utilities
Section 815-RICR-30-00-1.4 - Quality of Electric Service

Universal Citation: 815 RI Code of Rules 30 00 1.4

Current through September 18, 2024

A. Standard Frequency - The standard frequency for alternating current distribution systems shall be sixty (60) Hertz, with permissible variations not exceeding maximum and minimum values of 60.3 and 59.7 Hertz.

B. Service Voltage - The following service voltage standards shall be maintained at the point where the electrical system of the supplier and the electrical system of the user are connected.

1. Table 1 (These values are ANSI C84.1 (1989). Values shall change if ANSI adopts new standards.)

Established Standard Service Voltage

Minimum Voltage

Maximum Voltage

Type of Service

120

114

126

Single Phase

120/240

114/228

126/252

Single or Polyphase

208Y/120

197Y/114

218Y/126

Single or Polyphase

240

228

252

Single or Polyphase

480Y/277

456Y/263

504Y/291

Single or Polyphase

480

456

504

Single or Polyphase

600

570

630

Single or Polyphase

2400

2340

2520

Single or Polyphase

4160Y/2400

4050Y/2340

4370Y/2520

Single or Polyphase

12470Y/7200

12160Y/7020

13090Y/7560

Single or Polyphase

2. For distances exceeding a 2-mile radius from any distribution sub-station serving the customer, the minimum permissible voltage shall not be less than 97% of the minimum values shown in Table 1, § 1.4(B)(1) of this Part.

C. Momentary Fluctuations - Momentary fluctuations of voltage and/or frequency at the customer's service shall not be construed as non-compliance with this Section (§ 1.4 of this Part) and for the purposes of these Rules a momentary fluctuation of voltage and/or frequency shall be defined as a change in voltage and/or frequency not exceeding a three (3) second time interval of a non-periodic recurring cycle; provided, however, that fluctuations in frequency and/or voltage having continuous and/or recurring periodic time cycles shall not be considered as compliance with this Section (§ 1.4 of this Part); and the public utility shall immediately initiate and complete all necessary action to eliminate and/or correct the cause of such fluctuations, if found to originate directly or indirectly within the public utility's system.

D. Abnormal Conditions - These Rules shall not apply to temporary conditions due to acts of God, windstorm, fire, strikes, insurrections, construction and/or maintenance or other disruptions of service beyond the immediate control of the public utility; provided, however, that all public utilities shall initiate immediate action and proceed without delay and perform all necessary work to restore its system and/or customers' services to normal operating conditions.

E. Special Provisions - No public utility shall be required to maintain service voltage according to Table I, at any point beyond the point where the electrical system of the supplier connects to the electrical system of the user if the wire or cables of the customer are

1. inadequate or undersized

2. not capable of delivering the customer's normal requirements for electricity, or

3. not in conformance with the requirements of the National Electric Code or any applicable statute, ordinance, rule or regulation of any authority having jurisdiction.

Disclaimer: These regulations may not be the most recent version. Rhode Island may have more current or accurate information. We make no warranties or guarantees about the accuracy, completeness, or adequacy of the information contained on this site or the information linked to on the state site. Please check official sources.
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