Browse Store Selling the equipment is only part of the job.
A large electrical distribution lineup may need to meet a very specific combination of amperage, voltage, breaker sizes, protection functions, physical configuration, and other project requirements before it is ready to ship.
This 4000-amp Eaton distribution lineup is a good example. The equipment is being configured in the EMSCO shop around a customer-specific breaker schedule, including a 4000A main breaker and feeder breakers ranging from 60A to 1200A.
And like many real-world projects, the requirements changed while the work was underway.
The basic lineup requirements
The project called for an Eaton main-breaker distribution lineup with the following specifications:
- 4000A
- 480/277V
- 3-phase
- 4-wire
- NEMA 1 enclosure
- 3-pole breakers
- 65k AIC-rated breakers
- 4000A main breaker
- Bottom-feed configuration
The main breaker also included LSIG protection, ground fault, and an energy-reduction maintenance switch. A surge protective device was also included in the lineup.
Projects like this are part of the larger range of low-voltage switchgear and distribution equipment EMSCO supplies and supports.
Configuring the breaker schedule
The main breaker is only one part of a distribution lineup.
The customer also required a specific combination of feeder breakers. For this project, the breaker schedule included:
- 1200A
- 800A
- 600A
- 200A
- 150A
- 60A
Multiple breakers were required at several amperages.
That means the lineup has to be configured around more than total amperage alone. Breaker frame sizes, mounting positions, available space, bus configuration, protection requirements, and the required feeder arrangement all have to work together.
The breaker schedule for this project was also revised while the equipment was being prepared.
That is part of working with electrical equipment for existing facilities and changing project requirements. A lineup may need to be adjusted as final load requirements, feeder sizes, or project scope are confirmed.
What do LSIG and AIC mean?
Specifications like these can have a major impact on whether a breaker is suitable for an application.
LSIG refers to four breaker protection functions:
- Long-time
- Short-time
- Instantaneous
- Ground fault
Different applications may require different combinations of these trip functions.
AIC, or ampere interrupting capacity, indicates the level of fault current a protective device is rated to safely interrupt.
For this project, the breakers were specified with a 65k AIC rating.
These are the kinds of details that matter when replacing, matching, or configuring industrial circuit breakers and existing power distribution equipment.
Used breakers — tested and documented
This project also demonstrates an important distinction when sourcing used electrical equipment.
The specification did not simply call for used breakers. It called for used breakers that were load tested with test reports.
For equipment like this, condition and verification matter. Testing provides documentation associated with the equipment rather than simply supplying a breaker pulled from inventory with no supporting test information.
EMSCO stocks used, tested, and refurbished circuit breakers across a wide range of manufacturers, amperages, voltages, and configurations.
Why existing electrical equipment often requires more than a part number
Large distribution equipment is rarely as simple as searching for a single catalog number.
When replacing, expanding, or modifying an existing system, important details can include:
- Manufacturer and equipment family
- System voltage
- Amperage
- Phase and wire configuration
- Breaker frame and trip rating
- Interrupting rating
- Trip functions
- Bus configuration
- Feed direction
- Physical dimensions
- Breaker quantity and arrangement
That becomes especially important when the equipment is older, obsolete, or no longer readily available new.
Sometimes the solution is an exact replacement. Other times, the equipment needs to be sourced, inspected, tested, reconditioned, or configured around the customer's existing system.
Having deep in-stock electrical equipment inventory, product knowledge, and in-house capabilities under one roof makes those projects easier to solve.
What happens after the sale
This Eaton lineup is a good example of what can happen after the equipment is sold.
The final product still has to match the actual project requirements before it leaves the shop. That can mean installing the correct breakers, adjusting the configuration when specifications change, verifying the equipment, and preparing the lineup for shipment.
This is not the only 4000A Eaton equipment EMSCO has worked with. You can also see a different application in our project on a 2600 kVA transformer and 4000A Eaton switchboard package.
EMSCO has spent over 75 years helping contractors, facility managers, electricians, and purchasing teams find difficult-to-source industrial electrical equipment. You can learn more about why customers turn to EMSCO when availability, compatibility, and lead time matter.
Need help with a distribution lineup or replacement equipment?
If you need help identifying or sourcing a distribution lineup, switchboard, circuit breaker, bus plug, or other replacement electrical equipment, send us the manufacturer, catalog number, specifications, or a clear photo of the equipment nameplate.
Request a quote or contact the EMSCO team.
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