Automatic backup generation built to perform when it's needed most. Carter engineers have supported standby projects across healthcare, municipal infrastructure, data centers, and commercial/industrial facilities.
Emergency lighting, fire pumps, alarms, and egress systems must remain operational during an outage. These are legal minimums — not design options.
NFPA 110 · NEC 700 · NEC 701Hospitals and clinical facilities operate under codes that specify not just that backup power must exist, but how fast it must respond. Life-safety and critical branches have to be online within seconds of an outage.
NFPA 99 · NFPA 110Pumping, treatment, and distribution cannot stop during a utility outage. Standby generation keeps these systems running — from remote pump stations to full treatment facilities serving entire communities.
State and local regulatory requirementsUptime commitments, SLA obligations, and Tier classification frameworks drive standby requirements in data centers — often well beyond code minimums. When downtime carries significant financial and reputational risk, the standby system is engineered to that risk.
NEC · NFPA 110 · Uptime Institute Tier StandardsA standby system connects a generator and a utility feed through an automatic transfer switch (ATS). The ATS monitors utility voltage continuously. When it detects a sustained loss of power, it signals the generator to start. Once the generator reaches operating speed and stable voltage, the ATS transfers the selected loads. When utility power returns and stabilizes, the system transfers back and the generator shuts down.
Load selection is one of the first engineering decisions in a standby project. Some installations back up life-safety systems only — fire pumps, egress lighting, a single elevator. Others back up the full facility. That decision drives generator sizing and shapes everything downstream. Carter engineers work through it with the project team early.
Generator ratings define how a unit is expected to operate — not just how much power it produces, but how often and under what conditions.
Standby rating: The most common configuration. The generator runs during outages and periodic testing, typically around 200 hours per year with a maximum of 500. Average loading should remain at or below 70% of rated capacity, though the unit can carry higher loads for limited periods. During an actual outage, there is no restriction on runtime.
Emergency standby: A lower duty-cycle rating — around 50 hours per year — for systems used rarely and briefly. If this profile fits a facility's actual requirement, temporary or rental generation may be worth evaluating instead. Explore rental power →
Carter engineers work through rating requirements with every project team. The right rating for the application affects sizing, configuration, and long-term performance.
Fuel selection involves tradeoffs that go beyond upfront cost — availability, site infrastructure, and how the fuel performs under standby-specific conditions.
Diesel: The most common choice: fast starting, widely accepted in code-driven environments, and familiar to the contractors and inspectors who work in healthcare, municipal, and commercial construction. The standby-specific challenge is storage. A generator that runs only for weekly testing doesn't cycle through its fuel supply, and stored diesel degrades over time. Maintaining fuel quality requires a polishing system or a scheduled maintenance program.
Natural gas: Eliminates on-site storage entirely. In disaster scenarios, underground gas infrastructure often remains accessible when roads are blocked and diesel deliveries cannot get through. The tradeoff is cost — above roughly 200 kW, natural gas generator sets carry a meaningful price premium over equivalent diesel units.
Propane: Serves remote sites where neither option is practical.
Carter engineers work through these tradeoffs with every project team, including implications for permitting, site infrastructure, and the long-term service program.
A single generator is a single point of failure. For facilities where that risk is unacceptable, multi-generator systems provide the redundancy required.
The most common approach is N+1: one more generator than the minimum needed to carry the load. If any unit goes offline — for service, for a fault, for any reason — the remaining generators cover it.
Onboard paralleling: Integrated controls built into each generator's panel, linked to share load and coordinate output. Modern generator control platforms have made onboard paralleling increasingly practical — functions that once required dedicated external equipment are now managed through the generators' own controls.
Traditional switchgear: Handles paralleling through dedicated external equipment. Switchgear adds complexity but provides an additional layer of redundancy in the control infrastructure itself. Healthcare installations frequently use this approach, and it is often code-driven as much as it is an engineering preference.
Carter engineers configure these systems based on reliability requirements, electrical infrastructure, and project constraints.
A standby system is only as good as its maintenance program.
The issue isn't how hard the generator works — it's how long it sits. Batteries age. Fuel degrades. Electrical connections loosen. Cooling systems accumulate deposits. None of this is driven by operating hours. It's driven by time.
For equipment that runs continuously, problems surface during operation. For standby systems, they stay hidden — until the utility goes down and the generator has to run. That's why maintenance isn't an afterthought in standby system design. It's a requirement built into the solution from the start.
Carter supports standby installations through their full lifecycle — inspection, load testing, fuel management, and preventive maintenance designed for systems that spend most of their life waiting.
Most standby projects begin with an engineer who already knows the codes and already knows what the facility needs. Carter's role isn't to explain the requirement — it's to help translate that requirement into a system that performs reliably for the life of the installation.
Standby projects are shaped early — in the design phase, before the spec goes to bid. The decisions made at that stage, on sizing, fuel type, redundancy configuration, and transfer equipment, define how the system performs for decades. Carter engineers work with project teams during that phase, providing application engineering support and equipment specifications that the design can be built around.
That early engagement is what Carter brings to a standby project. The rest — equipment supply, commissioning, and long-term service — follows from it.
Multi-generator hospital installation. Paralleling configuration with life-safety and critical branch compliance under NFPA 99 and NFPA 110.
Multiple generator units · Paralleling configuration · Life-safety and critical branch complianceRange from remote pump station to full treatment facility. Illustrates Carter's range across project scale with regulatory compliance to state and local requirements.
Scalable across project size · Continuous load support · Regulatory complianceNot every situation calls for a permanent installation. During planned shutdowns, construction projects, or unexpected outages, facilities may need generator capacity on short notice. Carter's rental fleet provides fast-deploy temporary power for these situations.
Carter engineers are available to discuss system configuration, review the application, and help get the spec right from the start.
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