Class Code 3573
Power Supply Mfg
Class Code 3573 covers California employers that manufacture power supplies and related power-conversion equipment. This includes assembly, testing, and fabrication of AC/DC and DC/DC converters, UPS modules, transformers and switch-mode power supplies. The approved pure premium rate for 9/1/2026 is $1.648 per $100 of payroll, which insurers use as the base loss cost for these operations.
What Class Code 3573 Covers
This classification applies to facilities that produce power-supply products or subassemblies: PCB-level assemblies with power components, complete PSU enclosure assembly, transformer winding, heat-sink attachment, and final electrical testing such as hipot, insulation, and burn-in racks. Work includes component soldering (hand and machine), reflow/wave solder processes, wiring and harness assembly, high-voltage bench testing, calibration, and packaging. It covers both production lines in light manufacturing plants and smaller contract manufacturers that perform assembly and electrical testing for OEMs. The code is specific to manufacturing operations rather than purely design or sales activities; R&D bench activities that involve building and testing prototypes on the production floor are typically included.
Who It Applies To
- OEMs manufacturing internal power supplies for electronics and appliances
- Contract electronic assembly houses that build and test PSUs
- Manufacturers producing UPS units, inverters, and transformers
- PCB assembly shops handling power converter boards and reflow/wave soldering
- Production technicians, test engineers, and assemblers working on power modules
Common Job Duties
- Hand and automated soldering of through-hole and SMT components on power PCBs
- Assembly of heat sinks, enclosures, wiring harnesses and mechanical fasteners
- High-voltage testing including hipot, insulation resistance, and ground continuity
- Burn-in and functional testing under load, including thermal cycling
- Transformer winding, coil assembly, and crimping of power connectors
- Operation of reflow ovens, wave-solder machines, conformal coating and cleaning
- Final inspection, calibration of voltage/current outputs, and packaging
Common Injury Risks
Understanding the $1.648 Rate
The pure premium rate of $1.648 per $100 of payroll represents the estimated cost of losses for this class, exclusive of insurer expenses and profit. To estimate premium, divide total payroll by 100 and multiply by 1.648, then apply your insurer's loss adjustment factor, expense loads, state assessments and any experience modification. Final cost is affected by your loss history, safety programs, payroll mix across classifications, payroll misclassification audits, and program choices like deductibles or retrospective rating.
Cal/OSHA Compliance Requirements
Cal/OSHA requires employers manufacturing power supplies to implement electrical safety and control-of-hazardous-energy (lockout/tagout) procedures for equipment servicing and testing. Employers must also follow hazardous-chemical communication (HazCom/GHS) and provide ventilation, local exhaust and respiratory protection when soldering, cleaning or applying conformal coatings. Machine guarding, training for live testing and PPE for high-voltage work (insulating gloves, arc-rated clothing where applicable) are essential elements of compliance.
How Key HR Helps Employers Under Class Code 3573
A PEO like Key HR can help manufacturers in Class Code 3573 by centralizing workers' comp claims handling, providing tailored safety programs for electrical testing and soldering, and conducting on-site risk assessments to reduce losses. Key HR also assists with training, return-to-work programs, accurate payroll classification, and aggregated purchasing power to negotiate better insurance pricing and manage experience modification factors.
Get a QuoteFrequently Asked Questions
Does Class Code 3573 include prototype bench work and R&D testing?
Yes when prototype assembly and electrical testing are performed on the same production benches or in the manufacturing facility, they are typically included under 3573. Purely office-based engineering or design work is excluded and should be reported under the appropriate office/code.
How can I lower my workers' comp premium for power-supply manufacturing?
Focus on loss prevention: implement lockout/tagout, electrical safety training, local exhaust for soldering fumes, machine guarding, and a formal return-to-work program. Accurate payroll classification, separating office or sales staff into their correct codes, also lowers exposure.
What testing operations drive higher claims and how should they be controlled?
High-voltage hipot and live-load burn-in testing present elevated shock and arc-flash risk. Controls include engineering safeguards (interlocked test enclosures), written procedures, calibrated test equipment, insulated tools, lockout/tagout, and supervisor-led training with documented competency.
Quick Facts
- Class Code
- 3573
- Classification
- Power Supply Mfg
- Pure Premium Rate
- $1.648 / $100 payroll
- Effective Date
- September 1, 2026
- Source
- WCIRB Approved Filing
Manage Workers' Comp Through a PEO
Key HR provides pay-as-you-go workers' comp for California employers — no large deposits, no audits, better rates.
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