Three-phase power
for real loads.

208V and 480V service, motor circuits, VFDs, and control panels for machine shops, manufacturing floors, multi-tenant commercial buildings, and HVAC scopes across the South Bay. Licensed C-10, fully insured, PG&E coordination included.

  • 208V / 480VWye and delta
  • 1-50 HPMotor circuits sized to load
  • Net 30/60Commercial terms

What we do

From the service entrance to the machine.

Three-phase wiring sits between the utility and the equipment that actually runs the building. Monte Power & Electric handles the full path: PG&E service work, switchgear, distribution panels, motor branch circuits, disconnects, and the VFD or starter at the equipment.

Common scope is a manufacturing tenant improvement, a CNC or fabrication-shop fit-out, a multi-tenant building with mixed loads, or a rooftop HVAC swap that needs a new disconnect and a properly sized motor circuit. Same crew on the panel and the equipment, so the install ties together cleanly.

  • 200-1,600A Three-phase service sizes installed.
  • 1-2 wk Typical lead time on commercial mobilization.
  • $2M General liability coverage on every job.

By voltage & configuration

Sized to the equipment,
not the other way around.

The right voltage and configuration depends on the loads. We spec the service to fit the equipment, not force the equipment to live within the existing service. Walk us through what's coming in and we'll come back with the design.

01

208V wye three-phase

Most-common commercial

Standard for offices, retail, restaurants, light manufacturing, and multi-tenant buildings. Smaller motors, HVAC, and 120V branch loads off the same service. Common 200A to 800A range.

  • 208Y/120V four-wire
  • HVAC and small-motor loads
  • Mixed 120V branch on same service
  • Tenant improvement standard
02

480V wye three-phase

Industrial / manufacturing

The standard for serious motor and process loads. Larger HVAC compressors, CNC machines, fabrication equipment, conveyors, and pumps. Step-down transformers feed 208V or 120V branch loads downstream.

  • 480Y/277V four-wire
  • 10 HP and up motors
  • Step-down to 208V or 120V
  • Most-efficient for large loads
03

Motor circuits & disconnects

Branch-side scope

Dedicated motor branch circuits with overload protection, disconnects within sight of the equipment, and conductor sizing to nameplate full-load amps plus code-required margin. Compliance with NEC Article 430.

  • Disconnect within sight of motor
  • Overload protection per nameplate
  • Equipment grounding conductor
  • Single-motor or grouped circuits
04

VFDs & control panels

Variable speed

Variable frequency drives for HVAC fans, pumps, conveyors, and process motors. Includes input filters, output filters where the motor lead is long, control wiring back to a BAS or PLC, and start-up commissioning.

  • HVAC, pump, and process drives
  • Input and output filters as required
  • BAS / PLC control integration
  • Start-up and commissioning

Common applications

Where three-phase actually shows up in the South Bay.

Most commercial scopes Monte Power & Electric runs involve three-phase somewhere in the build. The eight below cover the majority of what we wire each month.

  • Machine shop fit-out with CNC mills, lathes, and fabrication equipment
  • Manufacturing tenant improvement with conveyors and process motors
  • Rooftop HVAC swap needing properly sized disconnect and circuit
  • Restaurant kitchen build with three-phase walk-ins and equipment
  • Multi-tenant commercial distribution and metering rebuild
  • Cleanroom and lab dedicated equipment and process power
  • Pump house wiring for water, irrigation, or process pumping
  • Property management common-area HVAC and elevator service

How a three-phase scope goes

Five steps from
nameplate to commissioning.

Same disciplined sequence whether the scope is one rooftop disconnect or a full machine-shop floor. The crew that designs the install runs the install.

  1. 01

    Scope

    On-site walk with mechanical and equipment specs in hand. Nameplate review, load calc, distribution sizing, and AHJ check. No charge.

  2. 02

    Quote

    Itemized quote with line items for service work, distribution, branch circuits, disconnects, VFDs, controls, and commissioning.

  3. 03

    Permit & PG&E

    Permit pulled, PG&E coordination scheduled where service-entrance work is involved. Transformer sizing and primary work handled.

  4. 04

    Install

    Distribution, conduit, conductors, gear, motor circuits, and controls installed on the agreed schedule. Coordinated with mechanical and equipment trades.

  5. 05

    Commission

    Final inspection, motor rotation check, VFD start-up, and BAS / PLC integration verified. Sign-off, photos, and warranty paperwork delivered.

Quick answers

Three-phase
questions.

Six of the most-asked. More on the dedicated contact page or by phone.

  • What's the difference between 208V and 480V?
    208V wye serves most commercial spaces and small motors. 480V wye is the standard for manufacturing, larger motors, and HVAC compressors. Choosing the right service voltage avoids upsized conductors and step-down losses later.
  • Do you install VFDs?
    Yes. We size, mount, and wire variable frequency drives for HVAC fans, pumps, conveyors, and process equipment. Includes input and output filters, control wiring, and start-up commissioning.
  • Can you wire a CNC or machine-shop floor?
    Yes. Three-phase machine power, dedicated motor disconnects, equipment grounding, and overcurrent protection sized to nameplate. Common scope for tenant improvement and manufacturing fit-out.
  • Do you handle PG&E coordination?
    Yes. New 208V or 480V three-phase service entrance work is coordinated with PG&E for transformer sizing, primary work, and meter set.
  • What about motor control centers?
    Monte Power & Electric installs and modifies MCCs, motor-control panels, and individual starters. Includes overload protection, contactors, and control wiring tied back to PLCs or BAS where required.
  • How fast can you mobilize?
    Most commercial three-phase scopes start within one to two weeks of approved quote. Emergency motor failures get next-day service.

Ready when you are

Get a quote on the
three-phase scope.

Send us the equipment list, the floor plan, and the timeline. We'll come back with an itemized quote and a mobilization date.