Days 1–30
Pre-install — coordination call
Equipment specs reviewed, power requirements confirmed, install location and disconnect placement agreed. Manufacturer tech scheduling target set.
Industrial Electrical Services · Pillar Guide
Machinery wiring, done to spec and labeled for the next decade.
Industrial machine installation, motor wiring, controls integration, equipment relocations — NEC-compliant, properly sized, labeled and documented.
11 yrsMarin electrical work
C-10CSLB licensed contractor
1st passInspection rate
48 hrTypical estimate turnaround
Key Takeaways
- Industrial machine wiring is governed by NEC Article 670 (industrial machinery) and Article 430 (motors) — different code framework than commercial.
- Equipment installs almost always involve coordination with the equipment manufacturer's service tech for final commissioning.
- Motor circuit sizing per NEC 430 uses 125% of full-load current for the conductors and specific overcurrent device rules — getting this wrong creates code violations.
- Disconnect placement (within sight, NEC 430.102) is the most-common preventable code violation on equipment installs.
- Documentation at install — including motor nameplate data, controls schematic, and a labeled disconnect — pays back many times over during future troubleshooting.
01 — OverviewWhat Machinery & Equipment Wiring actually covers in Marin.
Industrial machinery and equipment wiring is the install side of industrial work — bringing power, controls, and disconnects to production equipment ranging from small CNC machines to large process equipment. The scope sits between the electrical contractor (us) and the equipment manufacturer's service tech (who handles commissioning, calibration, and any equipment-specific final connections).
Most industrial equipment installs follow a standard sequence: site walk to identify panel capacity and pathway routes, design phase confirming circuit sizing and disconnect placement, rough-in phase pulling conductors and installing disconnects, equipment placement coordinated with the customer and rigging, final connection coordinated with the manufacturer's tech, commissioning and testing, and documentation handoff.
Definition
'Industrial machinery and equipment wiring' is the electrical install work for production equipment — including motor circuits, motor controls, disconnects, equipment power feeds, and the code-compliance and documentation work supporting it.
NEC Articles 430 and 670
Article 430 governs motors and motor circuits — sizing, overcurrent protection, controllers, disconnects. Article 670 governs industrial machinery (defined as equipment with multiple motors or controls integrated). Both apply to most industrial equipment installs; getting them right is what separates compliant work from inspection failures.
Manufacturer coordination
Industrial equipment manufacturers typically require their tech for final commissioning to maintain warranty. We coordinate scheduling so our scope (power to disconnect, labeled and tested) is complete before their scope (equipment-specific connections, programming, calibration) begins.
For the broader context this guide supports, see our Industrial Electrical Services overview.
Explore the Full Guide
Equipment wiring scope organizes by equipment type and by install sequence.
Three guides to read first
Cornerstone
Motor Circuit Sizing per NEC 430
Conductor sizing, overcurrent protection, motor controllers, and disconnect requirements per NEC 430.
Explore the guide →
Critical
Disconnect Placement & Lockout/Tagout
NEC 430.102 disconnect within sight, OSHA lockout/tagout requirements, and how to design for both.
Explore → CommonEquipment Relocation Electrical
What's involved in moving production equipment electrically — circuit recovery, rerouting, recommissioning.
Explore →Browse the Full Library
By equipment type
Controls integration
02Motor circuit sizing — the simplified rules.
NEC 430 sizing is rule-bound. Quick reference for the most common decisions.
Conductors
Sized at 125% of full-load current per NEC 430.22. So a 20-amp FLA motor needs conductors rated 25 amps minimum. Use motor nameplate FLA, not horsepower-table values.
Overcurrent protection
Branch circuit OCPD typically sized 175-250% of FLA depending on motor type and starting method — much higher than continuous loading would suggest, to allow for inrush. Specific multipliers per NEC 430.52.
Controller and disconnect
Motor controller sized to motor HP and voltage. Disconnect within sight of motor (NEC 430.102) and rated for the motor's locked-rotor current.
03Disconnect placement — the most common code violation.
NEC 430.102(B) requires a disconnecting means within sight of each motor or motor-driven machinery. 'Within sight' is defined as visible and within 50 feet. This requirement gets violated regularly during equipment installs because it's easy to assume the motor controller (often centralized in an MCC or panel room) doubles as the disconnect — it doesn't, unless it's within sight of the motor.
The compliant approach: every motor or machine gets a local disconnect within sight (typically a fusible disconnect or non-fused disconnect adjacent to the equipment), plus the motor controller in the MCC. The local disconnect supports OSHA lockout/tagout for maintenance and meets NEC requirements simultaneously. Cost is small ($180-$420 per disconnect installed); compliance value is significant.
04How equipment installs sequence with the manufacturer.
Most industrial equipment installs follow a predictable sequence with the equipment manufacturer's tech.
Days 31–60
Rough-in — power to disconnect
We pull conductors, install disconnect, set up controller location in MCC. Power tested to disconnect; documentation complete. Equipment ready to install.
Days 61–90
Equipment placement and final connection
Customer rigs equipment into place. We connect equipment to disconnect. Manufacturer tech arrives to commission — programming, calibration, equipment-specific testing.
05What good documentation includes.
Documentation at install time is what makes equipment maintainable years later.
Panel schedule update
New circuits added with descriptive labels (not 'Circuit 17' but 'CNC Mill - SE bay - 480V 3ph 50A'). Panel cover relabeled if needed.
Disconnect labeling
Disconnect labeled with equipment name, voltage, amperage, source panel and breaker. Standard arc flash label per current NFPA 70E.
As-installed records
Motor nameplate photographed, controls schematic delivered to facility, install-date documented. For maintenance contract customers, this goes into our digital records.
Frequently Asked Questions
Can you work with our equipment manufacturer's installer?
Yes — most industrial equipment installs require coordination with the manufacturer's service tech for commissioning, calibration, and equipment-specific connections. We handle the electrical scope to the disconnect; manufacturer handles equipment-specific scope past it. We've coordinated with dozens of manufacturer service techs across the Bay Area — straightforward handoff.
How much does a typical industrial equipment install cost?
Highly variable based on equipment size, voltage class, and distance from existing infrastructure. For a typical 480V 3-phase machine with 100A circuit, 50-foot run from MCC, dedicated disconnect, and labeling: $2,400-$5,200 for the electrical scope. For larger equipment or longer runs or new circuit additions requiring panel work, costs scale up. We quote each install specifically after site walk and equipment spec review.
Do you need a permit for industrial equipment installs?
Almost always yes. New motor circuits, new dedicated equipment circuits, panel modifications, and any new conductor pulls require an electrical permit from the AHJ. We pull permits for every install and the inspector signs off. Some smaller scopes (replacing existing equipment on existing circuits with no change in load) may be exempt; we check on each project.
What's a VFD and when do we need one?
VFD (variable frequency drive) is an electronic motor controller that varies motor speed by varying the AC frequency supplied to the motor. Used when the application benefits from variable speed: pumps, fans, compressors, conveyors with varying loads. Benefits: energy savings (running at part-speed when full speed isn't needed), soft-start (less inrush, less mechanical stress), process control flexibility. Costs: VFDs add $1,200-$4,800 to a typical motor install depending on motor HP and VFD features. Not needed for fixed-speed applications where the motor runs full-speed during operation.
How long does a typical equipment install take?
For a typical industrial machine install — single motor circuit, disconnect, MCC controller, dedicated circuit from existing panel — expect 1-3 working days of on-site electrical work, scheduled in coordination with the equipment delivery and manufacturer tech availability. Larger installs (multi-motor process equipment, new MCC installations, panel work) scale up to 1-2 weeks. We share the schedule at quote signing.
Do you do equipment relocations?
Yes — equipment relocation is a common scope. Process: disconnect existing equipment electrically, recover the circuit conductors if reusing, route new conductors to the new location, install new disconnect, reconnect equipment, coordinate manufacturer tech for re-commissioning. Cost depends on conductor reuse, distance change, and whether panel work is needed. Typical relocation runs $1,800-$4,800 for the electrical scope; lower when conductors can be reused, higher when new pathways are required.
How We Reviewed This Page
- Reviewed against current California Electrical Code (Title 24, Part 3) and 2023 NFPA 70 (NEC) provisions applicable to the topic.
- Pricing ranges reflect actual 2026 Towery Electric quote data from Marin County jobs — not third-party industry averages.
- Permit and inspection timing reflects current AHJ practice in Novato, San Rafael, Mill Valley, and unincorporated Marin County as of mid-2026.
- Technical review by Alex Towery, founder and C-10 #989290 holder, with 11+ years of California electrical work.
- All factual claims about code requirements were verified against primary sources (CSLB, CARB, PG&E, AHJ) at time of publication.
References
This guide reflects Towery Electric's professional standards as a California-licensed C-10 electrical contractor and is for general information. Site conditions, panel configurations, code amendments, and permit-authority requirements vary; final scoping, sizing, and code compliance for your specific address are determined on a paid site assessment. We follow California Electrical Code (Title 24, Part 3) and applicable NFPA 70 (NEC) editions adopted by your AHJ.