Quick answer
A service entrance conductor is one of the heavy wires that carry electricity from the point where the utility’s service drop or lateral connects to your building, through the meter, to the terminals of your main service disconnect.
They are the customer-side end of the service. Article 230 of the National Electrical Code sets their minimum size, routing and protection; the utility’s conductors upstream of the service point are outside the NEC.
Quick facts
The key facts about Service Entrance Conductor, with sources:
- Runs from
- The service point (splice to drop or lateral) to the service disconnect 1
- Minimum size of the feed
- Service conductors: 8 AWG copper or 6 AWG aluminum; 12 AWG for limited loads 1
- Overhead attachment height
- At least 10 ft above finished grade 1
- Ownership
- Usually the customer, per utility service rules 3
- Emergency disconnect (2023 NEC)
- Outdoor, readily accessible, marked for one- and two-family homes 2
Key takeaways
- Service entrance conductors are the last stretch of wire before your main breaker, and they have no breaker ahead of them in your house.
- The service point marks the handoff: utility wire before it, your wire after it.
- NEC Article 230 sets their size, routing and clearances.
- Damage here is serious because only the utility’s fuse can stop a fault.
- Replacing them is a permitted job done with the utility, usually during a panel upgrade.
What service entrance conductors are
Every home’s power arrives through a short chain. The utility’s transformer sends power through a service drop, overhead, or a service lateral, underground. At the service point, those utility conductors connect to your conductors. From there, service entrance conductors run to the meter and on to the main disconnect.
EC&M explains that a service is the conductors and equipment that connect the utility to the premises wiring, and that the service drop and lateral are utility-owned conductors from the transformer to the service point 1. Article 230 rules begin at the service point.
Upstream of all this, the utility moves power at high voltage and steps it down at substations and neighborhood transformers 4.
The last transformer makes the 120/240-volt split-phase supply your service carries: two hot legs and a grounded neutral 5.
So a typical home service has three service entrance conductors, two hots and a neutral.
On an overhead service, you can see them: a cable or conduit with a weatherhead running down the wall to the meter. On an underground service, they are hidden in conduit between the meter and panel.
How power travels through the service
- Utility transformer → service drop (overhead) or service lateral (underground)
- Service point splice → service entrance conductors → weatherhead or conduit down the wall
- Service entrance conductors → meter base → meter
- Meter → service entrance conductors → main service disconnect → panel → branch circuits
Types of service entrance conductors
| Type | Description | Where used |
|---|---|---|
| SE cable, style U (SEU) | Two insulated conductors with a bare concentric neutral | Overhead service down the wall to the meter |
| SE cable, style R (SER) | Insulated conductors plus neutral and ground in a round jacket | Meter to panel or feeders |
| Conductors in conduit | Individual wires in rigid, IMC or PVC conduit | Mast services and underground 1 |
| Underground service entrance conductors | From the lateral to the service equipment | Buried services; 230.30(B) lists 11 wiring methods 1 |
Example: overhead clearances that shape a service
Minimum clearances for overhead service conductors come from NEC 230.24 and 230.26 as summarized by Mike Holt in EC&M (April 2024) 1. Your local code edition may differ.
| Where the wires pass | Minimum clearance | Rule |
|---|---|---|
| Over walkable areas (120/240 V) | 10 ft | 230.24(B) |
| Over residential driveways and yards | 12 ft | 230.24(B) |
| Same areas, over 300 V to ground | 15 ft | 230.24(B) |
| Over streets and truck parking | 18 ft | 230.24(B) |
| Over railroad tracks | 24.5 ft | 230.24(B) |
| Above a roof (and 3 ft out from its edge) | 8.5 ft, with exceptions | 230.24(A) |
| Attachment point on the building | 10 ft above grade minimum | 230.26 |
A roof replacement that raises the roofline, or a new garage under the drop, can push a mast below these minimums, so the electrician may have to raise it. Our permits guide covers when service work needs one.
Where you see them
Outside on an overhead service, look for the weatherhead near the roofline and the cable or conduit running down to the meter. On an inspection report, defects may be listed as “damaged service entrance cable,” “missing drip loop” or “inadequate clearance.”
On a panel upgrade quote, “new service entrance conductors” or “new mast” means these wires are being replaced to match a larger service. Learn your current size with our service size guide.
What correct service conductors give you, and their limits
Done right
Limits
- No overcurrent protection on your side ahead of the main disconnect.
- Weather, UV and tree contact wear outdoor cable over time.
- Upsizing the service means replacing them, and often the meter base.
- Work requires utility coordination to cut and restore power.
Rules that limit how they run
What drives the cost of replacing them
No dollar figures here. See panel upgrade costs for how service work is priced.
- Service size. A larger service needs larger conductors.
- Overhead vs underground. Trenching and conduit add labor.
- Mast height. Clearance rules may require a taller mast 1.
- Meter base. Often replaced at the same time.
- Utility fees and scheduling. Disconnect and reconnect rules vary.
- Lifespan. Outdoor cable jackets age with sun and weather; inspections catch wear.
How service conductors get replaced
Replacing service entrance conductors is licensed electrician work coordinated with the utility.
- Load calculation and service size decision.
- Permit pulled; utility notified for disconnect.
- Utility cuts power at the service point.
- Electrician replaces mast, conductors, meter base and service equipment as needed.
- Inspection; utility reconnects and sets the meter.
Upkeep
- Look at the weatherhead and cable from the ground once a year.
- Keep trees trimmed away from the service drop; call the utility for that.
- After storms, look for a leaning mast or sagging wires.
- Have an electrician inspect older services; see electrical inspections.
Warning signs
A cracked or frayed cable jacket, a bent mast, wires pulled from the house, water stains under the meter, or lights that dim and brighten when big loads start can point to service conductor problems.
If wires are down or sparking, stay away and call the utility and 911. For damage without immediate danger, call an emergency electrician and the utility.
No breaker protects these wires
Service entrance conductors sit ahead of your main breaker, so turning off the main does not de-energize them. Never touch the mast, weatherhead, cable or meter. Only the utility can cut power to them.
Code rules
| Authority | Rule | Requirement |
|---|---|---|
| NFPA 70 (NEC) | Article 230, 230.23 and 230.31 | Size for the Article 220 load; service conductors feeding them at least 8 AWG Cu / 6 AWG Al (12 AWG limited-load exception) 1 |
| NFPA 70 (NEC) | 230.24, 230.26 | Clearances and 10 ft minimum attachment height 1 |
| NFPA 70 (NEC) | 230.8 | Raceways entering the building sealed 1 |
| NFPA 70 (NEC), 2023 ed. | 230.85 | Outdoor emergency disconnect at one- and two-family homes; replacements must comply 2 |
| Utility | Service requirements manual | Point of connection, ownership, metering 3 |
Service conductors vs related wiring
| Conductor | From | To | Owner |
|---|---|---|---|
| Service drop / lateral | Utility transformer | Service point | Utility 1 |
| Service entrance conductors | Service point | Service disconnect | Customer, usually 3 |
| Feeder | Service equipment | Subpanel | Customer |
| Branch circuit | Final breaker | Outlets and loads | Customer |
Myths
- Myth Turning off the main breaker kills the service wires.
- Reality They are on the supply side of the main and stay live.
- Myth The utility owns everything outside the house.
- Reality Ownership usually changes at the service point 3.
- Myth Any heavy cable can be used.
- Reality Article 230 limits wiring methods and minimum sizes 1.
State and utility differences
When this matters to you
Service entrance conductor size and condition matter when you upgrade service, add big loads, replace a roof under an overhead drop, or buy an older home. In each case, ask whether the service entrance conductors, mast and meter base are sized and in good shape.
Start with the load calculator to see whether your service is big enough.
Roof work alert
Re-roofing under an overhead service often disturbs the mast. Ask the roofer to coordinate with the utility and an electrician before work starts.
Questions about Service Entrance Conductor
What are service entrance conductors?
On an overhead service, they are the thick cable or conduit you can see running from the weatherhead down the wall into the meter, then on to the main breaker.
On an underground service they are buried or hidden in conduit. Either way they carry the full service current with no breaker of yours ahead of them.
Who is responsible for service entrance conductors?
Usually the homeowner. Ownership typically changes at the service point, where the utility’s conductors connect to yours. Snohomish County PUD, for example, puts that point at the service mast for overhead residential service and at the meter base for underground residential service. Check your own utility’s service manual.
What size are service entrance conductors?
Service entrance conductors are sized for the home’s calculated load under NEC Article 220.
The overhead or underground service conductors that feed them can be no smaller than 8 AWG copper or 6 AWG aluminum (230.23 and 230.31), except 12 AWG for limited-load installations. A 200-amp service uses much larger conductors than that minimum.
The electrician sizes them from the load calculation and the edition of the NEC your state uses.
Does turning off the main breaker shut off the service entrance wires?
No. Service entrance conductors are on the supply side of the main breaker, so they stay live when the main is off. Only the utility can de-energize them, by disconnecting at the meter or the service point. That is why work on them is coordinated with the utility.
How high must overhead service wires be?
Under NEC 230.24, overhead service conductors need at least 10 feet over walkable areas for 120/240-volt systems, 12 feet over residential driveways and yards, and 18 feet over streets. The attachment point on the building must be at least 10 feet above grade. Local codes may adopt different editions.
What is the difference between service entrance conductors and a service drop?
The service drop is the utility’s overhead wire from the pole to your house, ending at the service point. Service entrance conductors are your wires from that point to the main disconnect. The drop belongs to the utility and falls outside the NEC; the service entrance conductors fall under Article 230.
When do service entrance conductors need replacing?
When the jacket is cracked or frayed, the mast is damaged, water gets into the meter base, or the service is being upgraded to a larger size. Aging outdoor cable is common on older homes. A licensed electrician replaces them under permit, with the utility cutting and restoring power.
What is SEU and SER cable?
They are common service entrance cable styles. SEU has two insulated conductors wrapped by a bare concentric neutral and is often used down the wall to the meter.
SER has insulated conductors plus a neutral and ground in a round jacket and is often used from the meter to the panel or to feed a subpanel.
What is the 2023 NEC emergency disconnect rule?
The 2023 NEC Section 230.85 requires one- and two-family homes to have an emergency disconnect in a readily accessible outdoor location, on or within sight of the home, marked “EMERGENCY DISCONNECT.” When service equipment is replaced, the rule applies, so a service upgrade may add an outdoor disconnect.
Sources
- Mike Holt, NEC Requirements for Services, Part 1, EC&M (April 16, 2024), retrieved .
- Larimer County (CO), 2023 NEC Significant Code Changes, retrieved .
- Snohomish County PUD, Electric Service Requirements, Section 2: General Requirements, retrieved .
- U.S. EIA, Electricity explained: Delivery to consumers, retrieved .
- Energy Education (University of Calgary), Distribution transformer, retrieved .
Expert review
Written by the HyreElectrical Research team. Not yet reviewed by an outside expert. We say so rather than imply a review that has not happened; see our editorial policy.
How the numbers were checked: Code facts checked against Mike Holt’s Article 230 summary in EC&M and Larimer County’s 2023 NEC summary; ownership against Snohomish County PUD’s service requirements; supply chain against EIA and Energy Education on 2026-10-10.
Suggest a correction. We fix errors and say what changed.