200A Meter-Main Combo Service Upgrade Procedure

Why this matters

A 200-amp service upgrade is the most common large-ticket residential electrical job in North America. Demand for EV chargers, heat pumps, induction ranges, and battery storage has converted what used to be an occasional capacity job into a high-volume practice. The job is also the most public-facing piece of work an electrical contractor performs: the meter must come off and go back on with the utility, the work is visible at the curb, the inspector reviews it on a specific day, and the homeowner is without power for the duration. Coordinating the three stakeholders (utility, inspector, customer) while doing clean, code-compliant work in a constrained outage window is what separates a profitable upgrade from a multi-day callback. This SOP walks the prep, the day-of sequence, and the inspection-ready details for a meter-main combo replacement, the dominant configuration for new residential service in most jurisdictions.

Scope

This SOP covers replacement of an existing 100 or 150A overhead or underground residential service with a 200A meter-main combo (exterior service disconnect integrated with the meter socket), feeding either an indoor or exterior subpanel with a 200A main-lug load center. Underground service upgrades, manufactured-home services, and three-phase services follow the same general flow but require additional coordination.

Roles

• Project lead: confirms permit, schedules utility coordination, walks job with customer, signs off final
• Lead electrician: performs the install
• Helper: spotter, tool runner, ground-rod driving, trench-side work for underground feeds
• Customer: present at start for outage confirmation, sometimes required to be on-site for utility re-energization

Pre-job checklist (3 to 7 days before)

1. Permit issued. Most jurisdictions require a separate service-change permit identifying the new ampacity, conductor sizes, grounding electrode system, and disconnect location.
2. Utility coordination scheduled. Submit the utility's service-change application identifying:
   • New service ampacity (200A continuous)
   • New meter socket type. A standard 120/240 V single-phase residential service takes a 4-jaw socket; 5-jaw belongs on a 120/208 V network service, and 7-jaw on three-phase. Confirm jaw count, and whether the utility wants a lever (horn) bypass, against that utility's own service manual before ordering, because the wrong socket is a rejected inspection and a second outage
   • Location of the new meter on the building elevation
   • Anticipated date and outage duration
   • Customer account and address
3. Inspection scheduled for the same day or next morning. Most utilities will not re-energize without an inspector's release sticker.
4. Materials staged on truck: meter-main combo (verify utility-approved model number), 4/0 SER cable or 4/0 aluminum URD conductors per design, 200A main breaker confirmed already in the combo, two 5/8-inch by 8-foot copper-clad ground rods, #4 bare copper grounding electrode conductor, water-line bonding clamp, intersystem bonding termination, conduit and fittings sized to the conductor, lever-operated bypass meter if used, and weatherhead or service entrance fittings to match overhead or underground source.
5. Customer notified of the outage start time, expected duration (4 to 8 hours for a clean job), what will lose power, and that any sensitive equipment (medical, freezer, fish tank) needs alternate planning.
6. Walkthrough of the existing service to confirm conductor entry direction, available trench access if underground, suitable mounting wall, and clearance from gas meter, windows, and HVAC equipment.

Code clearances and placement

Service-disconnect location and meter placement are dictated by 2023 NEC and utility service standards:

• Meter location: per utility service standards; commonly 4 to 6 ft above grade to center of meter, on an exterior wall with unobstructed access
• Working clearance per NEC 110.26(A): 36 in deep, 30 in wide, 6.5 ft headroom in front of the disconnect
• Distance from gas meter: typically 3 ft horizontal per gas utility rules
• Distance from windows: typically 3 ft to operable openings
• Service-disconnect quick-disconnect rule, NEC 230.85 (2020+): rapid shutdown of all service conductors at an exterior, readily accessible location for first-responder access. A meter-main combo satisfies this rule because the main breaker IS the exterior service disconnect; a meter-only socket feeding an indoor main panel does not satisfy 230.85 without an additional exterior disconnect.

Day-of sequence

Step 1: Pre-outage prep at the customer's house (30 to 60 minutes)

1. Walk the customer through the outage one last time. Confirm freezers are at lowest setting, sensitive equipment is on UPS or unplugged, the customer has alternate plans for refrigeration if extended.
2. Set up cones and signage at the meter location.
3. Photograph everything: existing meter face, conductor entry, indoor panel busbar, ground electrode connections, and the readiness state of the work area.

Step 2: Confirm outage and pull the meter

1. Call the utility dispatch line to report the outage start. Some utilities require a confirmation callback before pulling.
2. Cut and lock-out any solar inverter disconnect or generator transfer switch.
3. Pull the meter. Some utilities require their crew to pull and reset; others issue a tag that permits the contractor to pull. Verify procedure in advance.
4. Verify absence of voltage at the panel main lugs. Prove the meter on a known live source, test the conductors, then prove the meter again; a non-contact tester is a first look, never the proof.
5. Understand what is still hot. Pulling the meter kills the load side. The line-side jaws of the socket are still connected to the utility and remain energized, with no overcurrent device between them and the transformer. Treat the line side as live for the entire job, keep one hand out of the enclosure, and do not let a helper reach past you into the socket. This is the single most common way a service upgrade injures someone, because the meter coming out feels like the power going off.

Step 3: Demo the existing service

1. Disconnect and label the existing service conductors at the panel.
2. Remove the existing meter socket, leaving the conductors temporarily in place if the entry path will be reused.
3. Inspect the entry penetration for damage; plan to seal with electrical duct seal at the end of the job.
4. If overhead, plan the weatherhead replacement separately; if underground, expose the URD termination point.

Step 4: Install the new meter-main combo

1. Set the enclosure and mark the mounting holes. Check for plumb before drilling; a racked enclosure binds the deadfront and the meter ring.
2. Fasten to structure, not to siding alone. Use backing or a mounting board rated for the load, and seal every penetration.
3. Confirm the meter socket height is within the utility's window (commonly 48 to 72 inches to centre, but it is utility-specific and gets rejected on inspection if wrong).
4. Land the service-entrance conductors on the line side, torqued to the label value with a calibrated torque wrench or screwdriver. Aluminium conductors get an anti-oxidant compound and a re-torque.
5. Install the grounding electrode conductor to the neutral bar and confirm the main bonding jumper is in place. This is the one and only point where neutral and ground bond.
6. Land the branch feeders and re-identify any conductors as required.
7. Seal the entry penetration with duct seal and re-fit the deadfront before the utility returns.

Step 5: Utility reset and commissioning

1. Call for the meter set or reset per the tag you were issued.
2. With the main off, have the meter installed and the socket sealed.
3. Close the main and verify voltage: leg-to-leg at nominal 240 V, each leg to neutral at nominal 120 V, and neutral-to-ground at near zero.
4. Energize branches one at a time and confirm no nuisance trips.
5. Re-torque the main lugs after the first heat cycle if the manufacturer calls for it.
6. Photograph the finished work, the torque settings and the label for the job record.

References

• 2023 National Electrical Code, Article 230 (Services), Article 250 (Grounding and Bonding), Section 230.85 (Emergency Disconnect)
• NEC Section 110.14(D), Torque requirements for terminations
• NEC Table 250.66, Grounding Electrode Conductor sizing
• NEC Table 250.122, Equipment Grounding Conductor sizing
• NFPA 70E, Standard for Electrical Safety in the Workplace
• IEEE Std 142, Grounding of Industrial and Commercial Power Systems (informational)
• Square D / Eaton / Siemens / Milbank meter-main combo installation instructions for the specific model
• Local utility service requirements manual (NSTAR, ConEd, PG&E, etc.) for the service territory