The 3750 kVA substation transformer is built for primary distribution service, stepping medium- or high-voltage supply down to a distribution or utilization voltage. It is supplied with throat or bus connections for integration into a switchgear lineup. At 3750 kVA it operates as a distribution substation transformer with full radiator banks and high-voltage bushings.
Specifications
| Rating | 3750 kVA |
|---|---|
| Phase | Three phase |
| Primary voltage class | 15kV / 25kV / 35kV / 46kV / 69kV |
| Secondary voltage class | 4160V / 480V / 12470V / 24940V / 34500V |
| Basic insulation level (BIL) | 95 kV / 125 kV / 150 kV / 250 kV / 350 kV |
| Frequency | 60 Hz |
| Temperature rise | 65 °C |
| Winding material | Aluminum |
| Insulating fluid | Mineral oil, Type I |
| Cooling class | ONAN |
| Taps | Plus/minus 2 x 2.5% full-capacity below and above nominal |
| Enclosure | ANSI 70 gray |
| Feed configuration | Per application |
| Standards | ANSI/IEEE C57.12, NEMA |
| Lead time | 12–16 weeks |
Full-load current
Rated secondary current for a 3750 kVA unit at each available secondary voltage. Use these figures for conductor, breaker and bus sizing.
| Secondary voltage | Full-load current |
|---|---|
| 4160Y/2400 | 520 A |
| 480Y/277 | 4,511 A |
| 12470Y/7200 | 174 A |
| 13200Y/7620 | 164 A |
| 13800 Delta | 157 A |
| 24940Y/14400 | 87 A |
| 34500Y/19920 | 63 A |
Rated primary current at each available primary voltage:
| Primary voltage | Full-load current |
|---|---|
| 2400 Delta | 902 A |
| 4160 Delta | 520 A |
| 4160Y/2400 | 520 A |
| 4800 Delta | 451 A |
| 7200 Delta | 301 A |
| 12000 Delta | 180 A |
| 12470Y/7200 | 174 A |
| 13200 Delta | 164 A |
| 13200Y/7620 | 164 A |
| 13800 Delta | 157 A |
| 13800Y/7970 | 157 A |
| 22900Y/13200 | 95 A |
| 24940Y/14400 | 87 A |
| 34500 Delta | 63 A |
| 34500Y/19920 | 63 A |
| 46000 Delta | 47 A |
| 69000 Delta | 31 A |
Typical applications
- Utility distribution substations
- Heavy industrial primary supply
- Large renewable generation collection
- Data center campus primary supply
Construction
Standard construction is aluminum windings in a sealed tank with mineral oil, ONAN cooled, 65 °C rise. The tank is welded and finished in ANSI 70 gray. A five-position no-load tap changer provides plus and minus two 2.5% full-capacity taps. Copper windings and natural ester fluid are available on request.
Standards and compliance
- Built to ANSI/IEEE C57.12 and applicable NEMA standards
- Factory test report supplied with every unit
- Supplied and supported by Bear Power Solutions, Jackson, Mississippi
Frequently asked questions
What voltages is the 3750 kVA available in?
The 3750 kVA is available with 15kV / 25kV / 35kV / 46kV / 69kV primary and 4160V / 480V / 12470V / 24940V / 34500V secondary. That is 58 configurations in total. Every voltage inside a class carries the same price and the same basic insulation level.
What is the lead time on a 3750 kVA?
Lead times are 12–16 weeks from order confirmation, depending on configuration and current factory loading. Non-standard voltages, accessories, custom enclosure work and non-standard fluid or winding material extend that. Confirm the delivery date with Bear Power Solutions before committing to a project schedule.
Can this be supplied with a switchgear throat connection?
Yes. Substation transformers are commonly supplied with primary and secondary throat or bus connections for direct integration into a switchgear lineup. Specify the mating arrangement at time of quotation.
Can the 3750 kVA be supplied with copper windings or natural ester fluid?
Standard catalog construction is aluminum windings with mineral oil. Copper windings and natural ester fluid are available on request. Both affect price and lead time, so request a quotation for a non-standard build.
What standards does the 3750 kVA meet?
Units are built to ANSI/IEEE C57.12 and applicable NEMA standards. Factory test reports are provided with every unit.
Sizing the 3750 kVA
At its lowest available secondary voltage the 3750 kVA draws 4,511 A at full load; at its highest it draws 63 A. That spread is what makes secondary voltage selection an installation-cost decision as much as an electrical one – the higher voltage cuts conductor size for the same delivered power.
Secondary current at this rating is high enough that parallel conductor runs or busway are normally required on the low-voltage side. Confirm the secondary termination arrangement and available bus space before ordering.
Request a quote
For a firm price on a 3750 kVA in a specific voltage configuration, or for a non-standard build with copper windings, natural ester fluid or custom accessories, send the details below and Bear Power Solutions will respond with a written quotation.
