Okay, this is a common situation, and you're right to be concerned about complying with the NEC (National Electrical Code) and local requirements in California. Let's break down the scenario and address your questions.

General Considerations



NEC is a Minimum Standard

The NEC provides minimum safety requirements. Local jurisdictions (city, county) always have the authority to amend or add to the NEC. You must check with your local building department or electrical inspector. California also has its own specific amendments to the NEC.

Permitting is Essential

This temporary and permanent work requires a permit and inspection. Doing otherwise is inviting trouble (fines, delays, potential safety hazards). The inspector is the final authority on interpretations.

Coordination

Communicate clearly with the utility company (PG&E, Southern California Edison, etc.) and your local inspector throughout this process. They will have specific requirements for service drops, meter locations, and grounding.

Licensed Electrician

You stated "I will run it after the meter" indicating the likelihood of you doing the electrical work. As you know, most electrical work requires to be done by licensed contractors.

Addressing Your Specific Questions


Can a branch circuit run overhead on the same pole as the service feed? Potentially, but HIGHLY unlikely without special considerations/requirements. NEC Article 230 (Services) and Article 225 (Outside Branch Circuits and Feeders) cover this. The major concern is clearance and separation. You can't simply run a branch circuit alongside a service drop without maintaining proper clearances. The NEC requires separation between service conductors and other conductors, especially branch circuits. Think about the possibility of a fault on either the service or the branch circuit. The main concern is safety.2. If so, what is the minimum distance from this service feed wire to this branch circuit wires feed? This is where it gets very specific and depends on voltage, conductor type, and location. Consult NEC Articles 230 and 225. Table 230.51(C) and the notes accompanying it are relevant. Also refer to 225.26 and 225.
27. In general, you're looking at several feet of separation, and possibly even requiring a physical barrier between the service and branch circuit conductors. Think several feet, not inches. In reality, the clearances are often so stringent that it's simply impractical to run the branch circuit on the same pole as the service. That is why there are requirements for "service mast" and "meter pole" to protect the service conductors.3. Can I use PVC conduit on this temp branch circuit? Will it be strong enough to support the "pull-strength" from the wires? Yes, you can use PVC conduit for the temporary branch circuit, but you MUST support it properly. PVC conduit can be used overhead, but it requires very careful support to prevent sagging or breakage. Use appropriate support straps/clamps at regular intervals (check the NEC and manufacturer's instructions for spacing requirements). These intervals will be considerably shorter than for rigid metal conduit. The pulling strength of the wires is not a primary concern if you are pulling the wires through the conduit according to code. Consider using a stronger conduit type like rigid metal (RMC) or intermediate metal (IMC) for overhead runs, especially in temporary situations. This will give you a more robust and less sag-prone installation.

Recommended Approach (Temporary Setup)


Consult with the Utility Company

The utility must be involved in disconnecting and reconnecting the service drop. They will have specific requirements for the temporary pole and its location.2.

Temporary Service Pole (Properly Installed)

The temporary pole must be properly sized and installed to meet the load requirements of the triplex. It needs to be firmly grounded. Use a weatherproof disconnect at the pole.3.

Underground is Safest (and Often Required)

The safest and most code-compliant approach is to run an underground temporary feeder from the temporary service pole to the existing triplex. This eliminates clearance issues.4.

If Overhead is Absolutely Required

If underground is not possible, and the inspector approves an overhead temporary feeder: Use a separate pole for the temporary feeder from the temporary service disconnect to the triplex. Do not try to share the same pole as the service drop. Maintain all required clearances from buildings, ground, and other conductors. Use appropriately sized and rated conductors and conduit (RMC or IMC is recommended). Support the conduit at very frequent intervals to prevent sagging.5.

Grounding

Ensure proper grounding at both the temporary service pole and the triplex.

Important Considerations



California Amendments

Research California-specific amendments to the NEC related to services, feeders, and temporary wiring.

Working Space

Provide adequate working space around the temporary service disconnect and meter.

Accessibility

Make sure the meter and disconnect are readily accessible.

Weatherproof

All temporary wiring and equipment must be weatherproof.

Temporary Wiring Time Limits

The NEC limits the duration of temporary wiring installations (see Article 590). Plan the permanent installation as quickly as possible.

In summary: Running a branch circuit on the same pole as the service drop is highly problematic from a code compliance and safety perspective. Underground is almost always the better option for temporary feeders. Contact the utility company and get a permit before starting any work. Coordinate closely with the electrical inspector to ensure your temporary and permanent installations meet all requirements. Flag for review