Wrong settings either trip healthy units during a minor disturbance or fail to clear a real fault fast enough. Both outcomes risk damaged generators, switchgear fires, long outages and safety incidents that put your people and your contracts in danger.
USP&E as Your Guide to Protection That Matches Your New Fleet
Run a full short-circuit, coordination and arc flash study for your new fleet configuration. Check that each relay discriminates correctly, that backup protection operates if primary fails and that arc flash labels match reality. Test settings with secondary injection before commissioning, then verify them with recorded events after, so you know the relays behave in real disturbances as they did on the test set.
Collect the Settings and the Single-Line Truth
Start with what is really installed on your bus, not what the drawings say. Download settings from every relay, check firmware versions, verify CT and VT ratios on site and walk the single-line diagram against the switchgear. You may well find relays with temporary settings that became permanent, or drawings that were never updated after a modification.
Record everything in one settings database with revision control. That gives you a reliable baseline for your new study, and it lets you see exactly what changes when your gas turbine generators connect. Without it, every later fault investigation starts with an argument about what the settings were. Keep the database current after every change, and make one engineer responsible for approving edits.
Understand What Changes When Turbines Join the Bus
Your turbines raise fault levels, change the impedance seen by your relays and bring generator protection functions your engine relays may not have, such as reverse power settings suited to turbines and loss-of-excitation curves for larger machines. Your switchgear ratings must be checked against the new fault level before anything is energised, because a breaker asked to interrupt more current than it was built for can fail violently.
Frequency lock is non-negotiable. A 50 Hz Cat island cannot “almost match” a 60 Hz GT generator without engineered conversion. Keep the Cat genset bridge on one coherent Hz family so protection settings, transformer choices, and O&M training stay sane.
Coordinate Frame 6B Bridges, Engine Stations and Future Blocks
A remanufactured GE Frame 6B or used or new gas turbines connected as bridge capacity need settings that coordinate with your Cat gensets and natural gas engines. Bridge units often come with older relays, so decide whether to retain, update or replace them, and make sure your crews can read and test whatever you keep.
Cat genset packages already serve continuous process, peaking, and utility-adjacent islands. Natural gas engine stations extend that duty when gas arrives — without forcing a Frame-class jump. Keep TCO themes honest: fuel price volatility, overhaul tempo, spare lead times, and crew skill transfer. Do tables or EPC $/MW. When NG recip still wins on load steps and technician reality, write that into the RFQ instead of chasing turbine logos that the fuel corridor cannot support.
Proof from recent work
Mining · Tanzania
Perseus Mining, Nyanzaga Gold Project
USP&E supplied 28 Cummins KTA50 containerised gensets for the Nyanzaga Gold Project in Tanzania.
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 ›Data centres · USA
Major US hyperscale developers
USP&E refurbished 7 GE Frame 6Bs to zero hours in-house for major US hyperscale developers.
Your path from first call to reliable power
Paralleling is where a Cat genset fleet either becomes a disciplined power plant or a source of nuisance trips. Owners preparing for AI gas turbines need that discipline written into controls, protection, and operator practice before the first turbine arrives.
- Walk down the switchroom and collect single-line, relay models, firmware, setting files, CT/VT ratios, and breaker data.
- Issue a coordination study with proposed settings, synchronising logic, and a version-controlled change procedure.
- Inject, trip-test, and verify every relay against the approved file before handover.
Common questions
Why must protection relays change when gas turbines join a Cat genset bus?
USP&E reviews protection because turbines raise fault levels, change impedance and need generator protection functions engines may lack. Settings that worked for the engine fleet can trip healthy units or fail to clear real faults once turbines connect to the same bus.
What should a protection settings audit include?
USP&E downloads settings from every relay, checks firmware, verifies CT and VT ratios on site and walks the single-line diagram against the switchgear. Results go into one revision-controlled database, which becomes the trusted baseline for the new protection study on your site.
How fast can USP&E respond to a protection review?
USP&E can review relay settings, single-line diagrams and fault records as soon as you share them. Engineers flag urgent risks first, such as switchgear ratings exceeded by new fault levels, and the full study timeline depends on data quality and site access.
Is an arc flash study needed when turbines are added?
USP&E recommends a new arc flash study whenever turbines are added, because higher fault levels and changed clearing times alter incident energy. Labels, personal protective equipment and safe working distances must match the new configuration before anyone works on energised equipment.
Should bridge turbine relays be replaced?
USP&E decides case by case whether to retain, update or replace relays on bridge turbines. Older relays may lack functions or communications needed for coordination, so the decision depends on the protection study, spare parts availability and how long the unit will stay.
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.
Is your fleet putting uptime at risk?
Tell us your load, fuel and timeline. A USP&E engineer will come back with options for Cat Genset projects, not a sales pitch.