If the auxiliary scope is vague, the risks show up late: transformers too small for the real load, essential supplies missing, nobody responsible for start-up power and gaps between the package supplier and the site contractor. That means delay at commissioning, failed starts and a unit that cannot restart after a blackout.
USP&E Helps You Define Auxiliary Power Before It Becomes a Gap
We know you want a package that starts, runs and restarts without surprises. USP&E has delivered 150+ power projects in 45+ countries, with 25,000 MW contracted since 2002, and our 400+ engineers and project managers specify, build and commission new gas turbine plant. Our systems are ISO 9001 and ISO 45001 certified, and every deal runs under FCPA and OFAC controls. USP&E is a full-service EPC and O&M contractor, not a broker.
You do not need to design every circuit yourself. You need a full load list, clear supply categories and a scope split that says exactly who supplies, installs and tests each item.
Build a Complete Auxiliary Load List
List every auxiliary load on your package and on the plant around it: lube oil pumps, hydraulic and starting systems, enclosure ventilation, fuel gas heaters, filter house heaters, cooling fans, controls, battery chargers, lighting and small power. Add balance-of-plant loads such as fuel gas compression, water treatment and fire pumps.
Note the rating, duty and starting behaviour of each load you list. Large motors with high starting currents can dip voltage on a small auxiliary transformer. Loads that run only during start-up or cool-down matter as much as those that run continuously.
Our aeroderivative turbine guide shows how package designs differ, and those differences change the auxiliary load list.
Split Loads into Normal, Essential and Emergency Supplies
Not every load on your plant needs the same supply. Normal loads can stop when the unit stops. Essential loads, such as lube oil pumps during cool-down and turning gear, must keep running after a trip. Emergency loads, such as the DC lube oil pump, controls and protection, must run even when all AC power is lost.
Size your auxiliary transformers and motor control centres from the load list with a margin for growth, and decide how essential and emergency supplies are fed: from a diesel generator, a battery system or both. Check that changeover between supplies is automatic and fast enough to protect the bearings.
Decide where start-up power comes from when your unit and the grid are both down. A black start diesel, a battery or a neighbouring unit can all work, but the choice must be made early. Browse new and used turbine stock with that start-up plan in mind.
Write a Clear Scope Split and Test the Changeovers
Write your scope split so it says who supplies, installs, cables and tests each auxiliary item: package supplier, electrical contractor or plant EPC. Gaps usually appear at the boundaries, such as cables between the package and the motor control centre or the battery room that nobody owns.
Test your auxiliary changeovers during commissioning before the unit carries load. Trip the normal supply and prove that essential and emergency loads keep running. Record the results. This applies to new gas turbine generators, a remanufactured GE Frame 6B, other used/new gas turbines and natural gas engines/stations.
AI gas turbines, hyperscale generators and gas turbines for compute run under hyperscale EPC/O&M need the same tested auxiliary system, as does the New USP&E FX-45 45MW Modular Gas Turbine for the Hyperscale Data Center sector in the USA described on the new FX-45 page. For commissioning scopes, see our sister site on new gas turbines.
Local Teams Near Your New Gas Turbine Site
Data-centre schedules are won or lost in permitting, gas supply and interconnection, so USP&E puts its US offices first. Colorado Springs (1755 Telstar Dr, Suite 300) and Knoxville (800 S Gay St, Suite 700) give you two US bases for engineering reviews, procurement follow-up and site visits, and both teams work your new GT fuel gas specification alongside you rather than from a sales desk.
Behind them, London (162-168 Regent Street) handles structuring, bonding and finance; Johannesburg (22 Kildoon Rd, Bryanston) owns engineering and project controls for new gas turbine generators, fuel gas skids and bridge packages; Cape Town (31 Brickfield Road, Woodstock) supports design and commissioning; and Wuxi, China (No. 1, Ningzhou Road, Wuxi) manages China manufacturing and supply-chain follow-up.
For auxiliary power scopes, Colorado Springs and Knoxville engineers can review your load list, size transformers and motor control centres, and close scope gaps with your package supplier. Regions served: USA | AFRICA | UK | UAE | CHINA. That network stands behind 150+ power projects in 45+ countries and 25,000 MW contracted since 2002, run under ISO 9001 and ISO 45001 certified systems.
USP&E Track Record for New Gas Turbine
You want proof that USP&E has supplied and commissioned gas turbine plant for demanding clients. These projects show that record.
- USP&E has refurbished seven GE Frame 6B gas turbines to zero hours in-house for major US hyperscale data-centre developers.
- NEOM, Saudi Arabia: USP&E supplied three zero-hour Siemens SGT-400 gas turbines as the single technical and commercial interface, and the client reported savings of over $10 million. Read the case study.
- MAN redeployment, Iraq: USP&E moved a stranded 32 MW MAN plant, plus two surplus MAN generators, across four countries to an industrial buyer facing 12 to 18 month lead times for new engines. Read the case study.
HowTo: Define the Auxiliary Power Scope for a New GT
Your 3-step plan: 1. Share your package data, single-line diagram and scope documents. 2. Receive an auxiliary load list, supply plan and scope split. 3. Build, test the changeovers and commission with confidence.
- List every auxiliary load on the package and the plant: pumps, fans, heaters, controls and lighting.
- Split the loads into normal, essential and emergency supplies.
- Size auxiliary transformers and motor control centres from that list with a margin for growth.
- Decide where start-up power comes from when the unit and the grid are both down.
- Write a scope split that says who supplies, installs and tests each item.
- Test auxiliary changeovers during commissioning before the unit carries load.
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FAQ: New GT Auxiliary Transformer and MCC Scope
What is auxiliary power on a gas turbine package?
USP&E defines auxiliary power as the electricity your gas turbine package and plant need to start, run, stop and stay protected. It feeds lube oil pumps, fans, heaters, controls, chargers and lighting. Some auxiliary loads must keep running after a trip or a total loss of AC power.
What is the difference between essential and emergency supplies?
USP&E uses essential supplies for loads that must keep running after a trip, such as cool-down lube oil pumps and turning gear. Emergency supplies feed loads that must run with no AC power at all, such as the DC lube oil pump, controls and protection, usually from batteries.
How do I size an auxiliary transformer for a new gas turbine?
USP&E sizes auxiliary transformers from a full load list that includes ratings, duty and motor starting behaviour, plus a margin for growth. Large motor starts can dip voltage on a small transformer, so starting conditions matter as much as the continuous load.
Where does start-up power come from after a blackout?
USP&E plans start-up power from a black start diesel generator, a battery system or a neighbouring unit. The choice depends on the package, the plant and the grid. It must be made early, because it affects auxiliary transformer sizing, switchgear and the scope split.
Where are USP&E’s offices for new gas turbine projects?
USP&E leads new gas turbine projects from Colorado Springs and Knoxville in the US. London supports contracts and finance, Johannesburg and Cape Town add engineering and field depth across Africa, and Wuxi follows up transformers, motor control centres and equipment made in China.
Has USP&E delivered gas turbine projects before?
USP&E has refurbished seven GE Frame 6B gas turbines to zero hours in-house for major US hyperscale data-centre developers. Public case studies also include zero-hour Siemens SGT-400 units for NEOM and a stranded 32 MW MAN plant redeployed to Iraq.
Is USP&E a broker for new gas turbines?
USP&E is not a broker. USP&E specifies, supplies, builds and commissions gas turbine plant with its own people, so the team that defines your auxiliary scope is the same team that tests the changeovers, commissions the unit and answers for the result.
How fast can USP&E review an auxiliary power scope?
USP&E can start reviewing your package data, single-line diagram and scope documents as soon as you share them. Engineers flag missing loads and scope gaps first, so they can be closed well before equipment is ordered and contracts are fixed.
Make Sure Your Turbine Can Always Restart
Define your auxiliary power properly and your unit starts, trips safely and restarts after a blackout. Leave gaps and the first total power loss finds them. USP&E will help you define, build and test the scope with confidence.
Request a fast quote for your new GT fuel gas specification on the USP&E contact page, call +27 10 822 2324 or email info@uspeglobal.com. Want to see what is available today? Search the USP&E inventory.
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