Union Electric Company d/b/a Ameren Missouri: generator, battery backup & CPAP rules
Service area: Central and eastern Missouri, including the greater St. Louis area: 64 counties and more than 500 communities.
Meter collar transfer switches
No published rule found
Ameren publishes an approved meter collar list (ConnectDER Solar, ConnectDER IslandDER and Enphase IQ Meter Collar) and installation rules. On Ameren's construction resources page, both are listed under Ameren Illinois, and the rules are written for Ameren Illinois territory. We found no Ameren Missouri statement on meter collars. Ask Ameren Missouri before buying a Tesla Backup Switch, GenerLink or any other collar.
Generator and battery disconnect requirements
Ameren's backup generator connection request covers generators that switch over with an open transition, or with a closed transition shorter than 100 milliseconds. For services under 600 volts, you need a main service disconnect that can be padlocked open, a UL-listed transfer switch, and permanent signs at the meter and at the disconnect. The generator may not run in parallel with Ameren's grid for peak shaving, serving normal loads or testing. Ameren Missouri lists approved transfer switches. For net-metered solar, an AC disconnect must be within 10 feet of the meter and visible and accessible to Ameren at all times.
Gas meter upgrades for standby generators
Gas utility: Ameren Missouri in its gas areas of central and eastern Missouri; Spire Missouri in the St. Louis region and western Missouri
Neither Ameren Missouri nor Spire publishes a generator-specific gas meter upgrade policy or fee. The natural gas generator pre-authorization form on Ameren's site is for Ameren Illinois only. Contact your gas company before adding a generator.
- Ameren: Construction Resources (natural gas generator form listed for Illinois)
- Ameren Missouri news release: natural gas meter upgrades (135,000 gas customers)
- Spire: Contact Information (service areas)
Estimate your gas load with our gas meter calculator and read how gas meter sizing works.
Medical program for CPAP, BiPAP and oxygen users
- Program
- Medical Equipment Registry
- What it provides
- Gives advance notice of planned outages so you can make other arrangements for your medical equipment. It does not prevent disconnection for nonpayment and does not give priority restoration after an outage. Separately, Ameren Missouri's Critical Medical Need Pilot Program funds community agencies that connect customers with critical medical needs to help, and customers with a verified critical medical need cannot be disconnected for 30 days.
- CPAP / BiPAP
- Yes. The registry form lists CPAP (Child), BiPAP and oxygen concentrators, along with ventilators, dialysis and other equipment.
- Renewal
- The registry form does not state a renewal period.
Backup battery or generator programs
- Program
- None found
- What it provides
- Ameren Missouri does not offer a backup battery or generator program for medical customers. Its registry form recommends that customers have a backup device or standby power source.
Frequently asked questions
Does Ameren Missouri allow meter collar transfer switches like the Tesla Backup Switch?
No published rule found. Ameren publishes an approved meter collar list (ConnectDER Solar, ConnectDER IslandDER and Enphase IQ Meter Collar) and installation rules. On Ameren's construction resources page, both are listed under Ameren Illinois, and the rules are written for Ameren Illinois territory. We found no Ameren Missouri statement on meter collars. Ask Ameren Missouri before buying a Tesla Backup Switch, GenerLink or any other collar.
Does Ameren Missouri have a program for customers who use a CPAP or other medical equipment?
Medical Equipment Registry: Gives advance notice of planned outages so you can make other arrangements for your medical equipment. It does not prevent disconnection for nonpayment and does not give priority restoration after an outage. Separately, Ameren Missouri's Critical Medical Need Pilot Program funds community agencies that connect customers with critical medical needs to help, and customers with a verified critical medical need cannot be disconnected for 30 days. Yes. The registry form lists CPAP (Child), BiPAP and oxygen concentrators, along with ventilators, dialysis and other equipment.
Does Ameren Missouri offer backup batteries or generator rebates for medical customers?
We did not find a current backup battery or generator program for medical customers at Ameren Missouri. Ameren Missouri does not offer a backup battery or generator program for medical customers. Its registry form recommends that customers have a backup device or standby power source.
How do I get a bigger gas meter for a standby generator in the Ameren Missouri area?
Ameren Missouri in its gas areas of central and eastern Missouri; Spire Missouri in the St. Louis region and western Missouri: Neither Ameren Missouri nor Spire publishes a generator-specific gas meter upgrade policy or fee. The natural gas generator pre-authorization form on Ameren's site is for Ameren Illinois only. Contact your gas company before adding a generator.