4000 kVA Pad Mounted Transformer

Primary Voltage Ratings: 12.47kV Grounded Wye
Secondary Voltage Ratings: 34.5kV Delta
H.V. TAP RANGE: +/- 2@ 2.5% LV taps
TYPE: Dead Front loop feed HV & LV configuration
BIL: 90/30kV
Standards: IEEE, ANSI, NEMA, NFPA
Application: Aux transformers For BESS
Power Rating: 4000 kVA
Cooling Method: ONAN

The 4000 kVA pad mounted transformer adheres to ANSI, IEEE, and NEMA standards and meets the requirements of Article 450 of the California Electrical Code. It serves as an auxiliary transformer in a Battery Energy Storage System (BESS) in California. Engineered to endure the harmonic voltages and currents generated by inverters, it can also withstand transient overvoltages caused by switching surges and faults. Additionally, it is capable of handling the significant load variations typical in BESS projects.

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Specifications
Accessories

RATINGS

Transformer Type: Three Phase Transformer - Pad-Mounted
Number of Windings: Two
Frequency: 60 Hertz
Capacity (HV & LV): 4000 kVA
Cooling Class: ONAN
Oil Type: Mineral
Temperature Rise: 65°C

Rated Voltages (Peak Voltage)

Primary Voltage Winding (H): 12.47 kV
Secondary Voltage Winding (X): 34.5 kV

Winding Connections

12.47 kV Winding (H): Grounded Wye
34.5 kV Winding (X): Delta

BIL Ratings

12.47 kV Voltage (H): 125kV
34.5 kV Voltage (X): 150 kV (200kV BIL winding)

Impedance at Base Capacity Rating: 5.75%

Maximum Sound Level at Maximum Capacity: NEMA TR1

Service Conditions

Ambient Temperature Range -40 C to 50 C
Altitude above Sea Level <3,300 ft

Contact Daelim Transformer for special requirements

Tap Changer: 5-position, 2 Above and 2 Below Nominal Voltage
Bay-O-net fuse
Current limiting fuse
Two-position load break switch
Schrader-type valve
Oil drain valve
Dial type thermometer
Pressure relief valve
Metal LV-HV barrier
Nitrogen filling plug
Nameplate
HV & LV bushing: dead front bushing
Lockable instrument enclosure

Daelim Transformer Certificates

This step-down electrical transformer operates at ±10% voltage. It features electrostatic shielding between the windings to discharge static electricity to the grounded core. The transformer’s surface protective coating is ANSI 61 light gray, providing corrosion resistance.

High and low voltage compartment bushings are of a loop feed design (six bushings), arranged for termination with 600 Amp dead break elbows in accordance with C57.12.34. The hinged compartment door is tamper-resistant, meeting the requirements of ANSI C57.12.28.

Factory Tests
Factory tests are conducted in accordance with ANSI/IEEE C57.12.90, including:

Resistance measurements
Polarity and phase relation
Ratio tests
No-load losses and excitation current
Load losses and impedance voltage
Impulse tests
Dissolved gas-in-oil analysis
Oil tests

Warranty and Support

Daelim Transformer offers 2-year and optional 5-year warranty services. After receiving your order, Daelim Transformer will provide transformer outline drawings for confirmation within 2-3 weeks. A production plan will be provided within four weeks, with monthly updates on production progress until the transformer is completed. You can access details at any time through our system, including drawing releases, production progress photos, manufacturing completion, final testing, and shipment.