If ATS logic is not rewritten, the risk is transfers to a source that is not ready, unsynchronised closures that damage equipment or loads left waiting while UPS batteries run down. Critical loads drop, and a single failure becomes a costly outage.
USP&E as Your Guide for Mission-Critical Power
USP&E Extreme Ownership designs redundancy as a system: machines, fuel, electrical, controls, and human procedures. See data center modular power for mission-critical loads.
Rewrite the Preferred-Source Table
List every ATS on your site, the loads behind it and the sources it can choose from: utility, gas turbines, diesels and any bus ties. Then decide your preferred order for each, considering which loads are life-safety, which are critical IT and which can wait. Life-safety transfers usually keep their own fast path to diesel, separate from the turbine logic.
Write what each ATS does when its preferred source fails, when the source returns and when two sources are available at once. Decide whether transfers are open, closed or delayed, and how long each takes. Every transfer must finish well within your UPS autonomy, with margin for a failed first attempt.
Prove Sync Checks and Transfer Timing
Closed transitions need sync checks so sources are matched before paralleling, and protection that limits how long they stay paralleled. Open transitions need delays that let motor loads decay before reconnection. Check that turbine response times suit the transfer timing, because turbines and diesels accept load differently.
Test each of your ATS units against each failure scenario during commissioning, using a load bank where needed, and record times and voltages. Natural gas engines used for intermediate loads should follow the same logic. Keep settings under change control so the proven design stays proven.
Bridge Units and Compute Growth in the Same Logic
If tie-breaker logic is not rewritten, the risk is a single fault that closes a tie at the wrong moment, spreads a disturbance across both buses or leaves a section without a source. UPS batteries run down, critical loads drop and your outage becomes a headline.
Where diesel bridge or dual-fuel legs exist, polishing and storage discipline still apply. Fleet O&M must see turbine and recip alarms on one operational culture — O&M for mission-critical generator fleets.
Train operators on manual transfers too. When automation fails, a clear manual procedure is the last line of defence for your critical loads.
Proof from recent work
Data centres · USA
Major US hyperscale developers
USP&E refurbished 7 GE Frame 6Bs to zero hours in-house for major US hyperscale developers.
Mining · Mali
Barrick Gold, Loulo-Gounkoto
USP&E refurbished the 104 MW power station, rebuilding more than 80 MW of Caterpillar CM32 engines and adding new zero-hour capacity.
Read the case study ›Mining · Tanzania
Perseus Mining, Nyanzaga Gold Project
USP&E supplied 28 Cummins KTA50 containerised gensets for the Nyanzaga Gold Project in Tanzania.
Your path from first call to reliable power
Automatic under-frequency or overload shed protects machines from cascade trips, but poor thresholds can drop Tier 1 before Tier 3. Manual shed depends on trained people who answer phones at 03:00. Most mission-critical sites need both: automatic protection with a priority map operators rehearse, plus supervised restore steps that do not slam motors back in one block.
Common questions
Should mission-critical diesels lose ATS proving when a gas turbine joins?
USP&E keeps ATS proving for every diesel path that still serves life-safety or critical loads. Turbines change the source list, but diesel transfers must still be tested, because they are often the fastest path when the utility and a turbine fail together.
Should transfers be open or closed transition?
USP&E chooses open, closed or delayed transitions per ATS based on load type, UPS autonomy and source behaviour. Closed transitions need sync checks and paralleling limits, open transitions need delays for motor loads, and every choice is proven during commissioning.
What should O&M cover after ATS redesign?
USP&E includes ATS maintenance, transfer tests, sync check verification, UPS battery tests, operator manual-transfer drills and change control in O&M. Each item has a named role, so the redundancy proven at commissioning remains in place years later, after every equipment change on your site.
Why owners choose USP&E
USP&E is a full-service engineering, EPC and O&M company, not a broker. One team designs, builds and runs your plant, so nothing falls between contracts.
Racing a go-live date?
Tell us your load, fuel and timeline. A USP&E engineer will come back with options for Mission Critical Generators projects, not a sales pitch.