Service Entrance Cables
There are two main types of service entrance cables: SER and SEU. SER cables are with a Style R reinforcement tape, and they typically deliver power from the service drop-down to the meter base to the distribution panel. SEU cables are most frequently used as panel feeders in branch circuit applications.According to the National Electric Code (NEC), service entrance cables are designed to be used for services. All service entrance cables are produced, tested, and marked according to UL 854 standards. Service entrance cables for underground use are UL Type USE or USE-2, and service entrance cables for aboveground use are UL Type SE, Style R or U.
Service Entrance Cable Characteristics
Aboveground service entrance cables are either SER or SEU. They have a moisture-resistant and flame retardant covering that enables them to easily pull through framing members and wooden joists in commercial buildings. Installation and application of all service entrance cables are specified by NEC Article 338.Conductor Materials
SEU and SER cables are manufactured with an AA-8000 series (ACM) electrical-conductor-grade aluminum alloy. Manufacturing underground UL Type USE and USE-2 cables that are not marked with any other type—such as RHH, RHW, or RHW-2—is done with an AA-8000 series (ACM) electrical-conductor-grade aluminum alloy or an EC-1350 grade aluminum alloy.SER and SEU cables have different anatomies that make them suitable for various parts of a project. For example, an SEU cable has a neutral conductor but lacks a ground conductor. Because ground conductors and neutral conductors are only joined at the point of service disconnect, SEU cables are only safe to use at the point of disconnect. On the other hand, SER cables have both neutral and ground conductors, which makes them safe to use after the service disconnect.
Service Entrance Cable Specifications
| Cable | SE Style R | SE Style U | USE–2 | Mobile Home Feeder |
| Number of Conductors |
2c + Bare Cabled 3c + Bare Cabled 4c + Bare Cabled | 2c + Bare Concentric | 1c | 3c + Insulated Ground |
| Aluminum Conductor Size |
8 AWG to 300 kcmil |
8 AWG to 4/0 AWG |
8 AWG to 1000 kcmil |
2 AWG to 4/0 AWG |
| Conductor Insulation |
Thermoplastic (UL 83) Thermoset (UL 44) |
Thermoset (UL 44) | ||
| Conductor Types | UL 83: THHN / THWN-2 UL 44: XHHW |
RHH / RHW-2 / USE-2 | ||
| Covering | Overall Tape-and-Finish | N/A | N/A | |
| Covering Material | 75 deg C PVC | N/A | N/A | |
| Covering Thickness |
Minimum Average: 30 mil Minimum Point: 25 mil |
N/A | N/A | |
| Sunlight Resistant | YES | YES | YES | YES |
| Impact and Crush Tested |
NO | NO | YES | YES |
| Direct Burial | NO | NO | YES | YES |
| Joist Pull Tested | YES | YES | NO | NO |
| Overload Test | YES | YES | ||
