Section 5 Types of Service
5.1 General Characteristics
The electric service furnished by the Department is 60 hertz alternating current, single and three phase.
5.2 Generally Available Types of Service
The type of service (number of wires, phase, and voltage) furnished by the Department depends on two factors (1) the voltage available near the service location and (2) the type of service which in the Department’s judgment can most economically be made available to serve the nature, size, and location of the Customer’s requirements. The voltages and number of phases generally furnished are listed in Table 5.2-1 by nominal service voltages. However, a particular type of service may or may not be available at a given location. Therefore, during the Customer’s design phase, the Department shall be consulted regarding the type of service desired.
Table 5.2-1. Generally Available Standard Transformations of Electric Service
| Types of Service | Typical Loads Served | |
| 1. | 1 phase – 120/240 volts – 3 wire | Residential and other small loads from 25 kVA to 250 kVA |
| 2. | 3 phase delta – 120/240 volts – 4 wire | Loads with both single and three phase requirements not exceeding 150 kVA Open delta – For small three phase loads Closed delta – Single phase load shall be 20% or less of total for loads between 150 and 1,500 kVA |
| 3. | 3 phase wye – 120/208 volts – 4 wire | Three phase loads from 50 kVA to 1,000 kVA |
| 4. | 3 phase wye – 277/480 volts – 4 wire | Loads between 150 kVA and 3,750 kVA where individual motors are 50 hp or greater |
| 5. | 3 phase wye – 2400/4160 volts – 4 wire | Contact Department for minimum load requirements |
Note: For specific information on voltage transformations and other delta services, contact the Department. Refer to Table 5.4-2 for allowable motor sizes for various voltages.
Table 4.2-1 does not include all types of service available. The Department also offers electric service at primary distribution voltages. Normally, the voltages offered at a given location are restricted to those that are already available. Contact the Department for further information on the availability of all distribution voltages not listed in Table 5.2-1.
5.3 Load Sheet
Upon completion of and application for service, new services for residential customers and all services for commercial and industrial customers will be required to fill out a load sheet that covers the following:
- Exact location(s) of premises, including street address if available, where service is desired.
- Type of service (including service voltage), equipment rating, and amount of electrical load to be installed.
- Total motor load (to include size(s) of largest motor(s), starting current(s), NEMA letter or code).
- General characteristics of equipment to be driven by motors.
- Date new electric service or alterations to existing service is needed.
- Desired point of delivery or service entrance location.
When the load sheet has been completed, a Department Engineering staff member will meet with the customer and design the service to best meet the needs of and be financially responsible to the customer and the city. All services will be designed based on the Customer’s completed load sheet. Without completion and submittal of this load sheet to the NLRED Engineering Department, SERVICE WILL NOT BE CONNECTED. It is paramount that the load sheet be completed and submitted to the Department as soon as possible.
To request a Load Sheet, please email nlred-engineering@nlr.ar.gov.
5.4 Availability of Three Phase Service
It is the Department’s policy to allow the Customer the widest selection of service types consistent with sound operation and with the type of service desired to best suit the electrical requirements. However, there are locations in
the Department’s service area where, for practical considerations, the selection must be limited. The Department has many areas in which three phase facilities are not available. In these areas, the Customer may be required to pay the incremental cost of providing three phase service. The cost of providing such facilities may be prohibitive in relation to the value of three phase service to the Customer. Therefore, the Customer should contact the Department to determine if any charges are associated with the desired service prior to making any decision concerning the purchase of electrical equipment.
5.5 Facilities for Highly Fluctuating or Special Loads
The Department normally provides facilities adequate to serve reasonably stable loads. Highly fluctuating loads such as welders, X-ray machines, and motors with unusual or frequent starting requirements, may cause the facilities normally provided to be inadequate. Highly fluctuating loads may interfere with other Customers’ electric service. In some instances, the most practical solution to these problems may be the installation of additional facilities to serve the Customer. Should the Department install such additional facilities, the Customer will be required to pay for them.
5.6 Temporary Service
The Department provides many types and classes of temporary service which may be available at the location for construction work, traveling shows, etc. The Customer must provide adequate protective devices for all temporary services. Poles to be used for temporary service shall be treated. Overhead temporary service poles are typically set no more than 75 feet from the nearest Department pole. See Drawing S-1 for a typical structure for temporary service from an overhead source. See Drawing S-2 (bottom) for a typical structure for temporary service from an underground source. The temporary service pole location for either overhead or underground service will be specified by the Department. Specific terms and conditions under which temporary service will be provided may be obtained from the Department.
5.7 Specialty Permanent Service
5.7.1 Services for Mobile Home Parks, Trailer Parks, and Individually Located Mobile Homes
Requirements for electrical service for mobile homes, mobile home parks and travel trailer parks differ from other types of service and must be given special consideration in each case. The Customer shall consult with the Department well in advance of any installation. For individually owned, permanently located mobile homes, see Drawing S-7 for a typical meter service installation from an overhead source and Drawing S-2 (top) for a typical meter service installation from an underground source. For mobile home parks or travel trailer parks, see Drawing S-7 or S-8 for overhead service and Drawing S-2 (top) for underground service.
5.7.2 Central Service Poles/Load Center Distribution Pole For A Farmstead
For farm and other Customers who have two or more points of utilization at contiguous locations and where it is more practicable to deliver service at a central service pole on the Customer’s property than at a building, the Department will deliver service under the following conditions:
- Central service pole will be installed, owned, and maintained by the Customer. Refer to Drawing S-8.
- Service entrance (or meter loop) and fused switch or circuit breaker (all to be owned by the Customer) will be installed on central service pole by the Customer.
- The Department will connect its service wires to the Customer’s service terminals on the central pole, this point of connection being the point of delivery of service.
- The wires extending from the central power pole to the Customer’s buildings or points of utilization will be a part of the Customer’s installation and will be installed and maintained by the Customer.
- No foreign objects such as television masts, bird boxes, etc. will be allowed on the pole.
5.7.3 Apartment Building Service
Where apartment buildings are contemplated, the Department should be contacted before plans are drawn, in order that adequate service be made available to the prospective tenants.
5.7.4 Vertical Distribution System
The Department will not install, own or maintain a vertical distribution system in multi-story buildings.
5.7.5 Service to Marinas and Boat Docks
The Department will provide electric service to marinas and boat docks terminating at a location on land that will be designated by the Department. The point will be located above the normal flood plain elevation. A disconnect switch must be installed at the point of delivery. With the exception of the meters, the Customer shall own, install, and maintain all facilities beginning at the point of delivery. Meters will be owned by the Department but may be installed near each boat slip. The Customer’s facilities must meet all requirements in NEC Article 555 and any other referenced code.
