When ComEd power drops, critical loads fail first – sump pumps, freezers, medical devices, POS systems, and network gear. This guide explains emergency power options in Chicago: standby generators, automatic transfer switches (ATS), and UPS battery backup – plus what must be sized, permitted, and maintained so the system works when storms hit.
What Counts as an Emergency Power System
Emergency power is not one product. It is a system that keeps selected loads running through an outage. Common building blocks include:
– Standby generator – natural gas, propane, or diesel unit that starts when utility power fails
– Automatic transfer switch (ATS) – senses outage and switches building loads to generator power
– UPS (uninterruptible power supply) – battery buffer that covers short gaps and protects electronics during the switchover
– Critical-load panel or subpanel – dedicated circuits for equipment that must stay on
Portable generators can help in a pinch, but they are not the same as a permitted standby system with an ATS. Improper portable setups are a common carbon monoxide and backfeed hazard.
Why Chicago Properties Need Backup Planning
Chicago outages spike during summer storms, winter ice, and grid stress events. Basement flooding risk makes sump pump backup especially important. Retail and offices lose sales and data when cash registers, Wi-Fi, and phones go dark.
Older 100-amp services in bungalows and two-flats may not support a whole-home generator without a panel upgrade. Capacity planning starts at the main panel – see our guide to electrical panel safety and upgrades.
Standby Generators vs. UPS: Different Jobs
Generators handle longer outages (hours to days) for larger loads: HVAC, well/sump, refrigerators, lighting, and selected receptacles. They need fuel, ventilation, clearances, and regular exercise cycles.
UPS units protect computers, servers, networking, and medical devices through brief interruptions and dirty power. A UPS alone will not run a home for a multi-day outage; a generator alone may still drop electronics during the transfer unless UPS covers the gap.
Many commercial installs use both: UPS for ride-through, generator + ATS for sustained operation.
Sizing: Critical Loads First
Do not size for every convenience outlet. List what must stay on: life safety, food storage, communications, security, and revenue-critical equipment. Add starting watts for motors (sump, furnace blower, AC) – those spikes often drive generator size more than continuous watts.
STS Electric evaluates panel capacity, fuel availability, and outage history before recommending a package. Oversizing wastes money; undersizing trips breakers and leaves critical rooms dark.
Permits, Fuel, and Interconnection
Chicago-area standby installs often involve electrical permits, gas-line coordination, and placement rules for clearance and exhaust. Improper interconnection can backfeed the utility and endanger line workers – that is why transfer equipment must be installed correctly.
DIY generator wiring is a frequent insurance and inspection failure. Licensed installation protects the homeowner and the grid.
Maintenance That Keeps Backup Ready
Standby systems fail when ignored. Monthly exercise cycles, battery checks on UPS units, ATS function tests, and annual service keep the system ready. After any utility-side storm outage, confirm the generator returned to utility mode cleanly and that the ATS did not stick.
When You Need Emergency Electrical Help Now
If you already have an outage with no backup – or a generator that will not start – you need repair service, not just a sales quote. STS Electric provides 24/7 emergency electrical repair in Chicago for outages, failed transfer equipment, and unsafe temporary setups.
Plan a System With a Licensed Electrician
Whether you need a whole-home standby generator, a commercial critical-load design, or UPS protection for office gear, start with a load assessment and panel review. Request a licensed residential electrician for home projects, or call (773) 721-1111 for commercial scoping across Chicago and Cook County.
