What contractors are needed for UPS systems, backup generators, ATS, and emergency power?
Emergency power systems — UPS, generators, and automatic transfer switches — form the backbone of resilience for critical facilities. Installing, commissioning, and maintaining these systems requires contractors with specific technical expertise and, in many cases, manufacturer-specific training.
UPS systems: manufacturer-trained installers
UPS systems for critical facilities range from small rack-mounted units (1–20kVA) to large three-phase systems (100kVA to several MVA). For small UPS systems, any licensed electrician comfortable with the manufacturer's installation manual can complete the work. For large three-phase UPS systems (from Vertiv/Liebert, Eaton, Schneider Electric, ABB), manufacturer-trained or certified installers are strongly preferred — and in some cases, required for the warranty to remain valid. Ask your UPS vendor for their installer certification program and whether they maintain a network of certified installers in your area.
Generators: licensed electricians with ATS experience
Generator installation for critical facilities requires a licensed electrician experienced in: generator startup and commissioning (often done with the generator OEM's field service team); ATS installation and sequencing; generator connection to the UPS bypass or direct to the main switchboard; fuel system coordination with the mechanical contractor; and generator load testing under realistic load conditions. Generator manufacturer certifications (Generac, Kohler, Cummins, MTU) are a positive signal — they indicate factory training on the specific equipment.
Automatic transfer switches: critical coordination
An ATS (automatic transfer switch) or STS (static transfer switch) is the critical component that transfers the load from utility to generator — or between two utility sources — in milliseconds to seconds. ATS installation requires precise coordination between the electrical contractor and the UPS and generator vendors to ensure transfer times, bypass sequences, and protection settings are compatible. For N+1 or 2N data center architectures, the ATS topology design must be reviewed by an electrical engineer before installation.
Emergency power systems: commissioning and testing
For critical facilities, it is insufficient to simply install emergency power equipment and energize it. Every system must be commissioned and tested under realistic conditions: full-load generator testing, ATS transfer time verification, UPS battery discharge testing, and black-start testing (starting from a complete power loss). These tests require coordination between the electrical contractor, the equipment vendors, and the facility operations team — and they must be completed and documented before the facility goes live.
Published · ElectriScout Editorial