Top 23 Switchgear Manufacturers in California 2026
Last updated
FirmsLedger lists 23 switchgear manufacturers headquartered in California. The largest clusters are in Anaheim (2), Corona (2), Ontario (2) and Sacramento (2), and the other 15 are in 14 more cities. Anaheim listings include Power Plus and L3Harris Power Paragon.
By specialty, California has electrical wire & cable (20), solar panels (19), wiring harness (7), transformers (7) and control panels (4) listings. Capabilities that more than one of them list include automatic transfer switches (ATS) (2), generators (2) and low voltage switchgear (2).
DEI Power Solutions
Ontario, California10-49 employees
Founded in 1999 in Ontario, California, DEI Power Solutions operates as a privately held manufacturer of custom low-voltage power distribution equipment. The company maintains its production facility in the Inland Empire region, serving customers across the western United States.
Industrial Electric Manufacturing (IEMFG)
Fremont, California
Industrial Electric Manufacturing (IEM) traces its roots to 1951 in Fremont, California. Now operating as The New IEM LLC, a subsidiary of IEM Holdings Group, Inc., the company has spent more than seven decades designing and fabricating custom power distribution systems.
Trayer Engineering Corporation
San Leandro, California
Trayer Engineering Corporation operates from San Leandro, California, where it was founded in 1962 as a pioneer in low-maintenance vacuum switchgear for electrical distribution systems. Now a Siemens company, the business is led by CEO Kevin Calister and continues to design and manufacture its products at its California headquarters.
Aggreko
Whittier, California1000+ employees
Aggreko, headquartered in Whittier, California, was founded in 1962 as a pioneer in temporary energy and temperature control solutions. The company, now publicly traded, began by creating the category for rental power equipment and has since expanded globally.
Bay City Electric Works
Poway, California70 employees
Bay City Electric Works was founded in 1932 by Bob and Leola Norris as a small appliance repair shop on University Avenue in San Diego. The business became a Kohler generator dealer in 1962 and was appointed Kohler's distributor for San Diego and Imperial Counties in 1971.
Castillo Electric Distribution
Signal Hill, California
Castillo Electric Distribution was founded in 2006 in Signal Hill, California, as an electrician-run wholesale electrical supplier. The company stocks and distributes a broad line of electrical products including switchgear, circuit breakers, panelboards, fuses, wiring, conduit, lighting, controls, tools, and safety gear.
- MV Circuit BreakersMission Viejo, California
- Pacific Electric IncCorona, California
- Power PlusAnaheim, California
- Steven EngineeringCorona, California
- Waukesha-Pearce Industries (WPI)Bakersfield, California
- Western Energy SystemsBrea, California
- L3Harris Power ParagonAnaheim, California
- Myers Power ProductsOntario, California
- RG Industries, LLCSanta Fe Springs, California
- Butcher Power ProductsSacramento, California
- Delta Power, IncSanta Ana, California
- Pioneer CEP (Pioneer Power Solutions)Santa Fe Springs, California
- The DySyn Group, LLCNorth Highlands, California
Frequently asked questions
Which switchgear manufacturers in California list automatic transfer switches (ATS)?
2 companies list it: Industrial Electric Manufacturing (IEMFG) and Bay City Electric Works.
Which certifications do switchgear manufacturers in California list?
UL 891: DEI Power Solutions, Industrial Electric Manufacturing (IEMFG) and Trayer Engineering Corporation. UL Listed: Aggreko, Pacific Electric and Steven Engineering. ISO 9001: Steven Engineering and Butcher Power Products.