7.5MVA trailer mounted substation

Incoming section

27kV 630A breaker

• Insulation class: 27kV rms
• Nominal service voltage: 27kV rms
• Frequency: 50/60hZ
• Rated continuous current at 40 C.: 630A
• Minimum ambient operating temperature: -60°C
• Maximum ambient operating temperature: 55°C
• Temperature rise: 80 C
• BIL: 150 kV BIL
• Power frequency withstand voltage (1 min dry): 70kV
• Power frequency withstand voltage (10 sec wet): 60kV
• Rated short-circuit breaking current: 12.5kA
• Rated short-circuit making current: 32.5kA
• Rated short-time withstand current (4 sec) : 12.5kA
• Mechanical life/ Operating cycles @ rated current: 30 000
• Operating cycles @ rated short-circuit breaking current: 200
• Closing time: less than 40ms
• Opening time: less than 15ms
• Break time: less than 28ms

Transformer section

7.5MVA power transformer :

• ABB RESIBLOC
• 7.5MVA ANN
• Insulation class: 155°C (standard for RESIBLOC)
• 80°C Rise
• Minimum ambient operating temperature: -60°C
• Maximum ambient operating temperature: 40°C
• Copper windings
• Primary: (dual primary voltage)
  • 13.8kV (Delta) BIL: 110kV
  • 25kV (Delta) BIL: 150kV
• Secondary
  • 7.2/4.16kV (Wye) BIL: 95kV
• IZ: 5.75%
• Enclosure:
  • NEMA 3R
  • Approximative dimensions: 138’’ H x 108’’ D x 180’’ W
  • Enclosure is rated for 90mph wind loads

PTO outputs section

2x 7.2kV PTO output including :

• 1x 7.2kV 800A mainbuss
• 1x 24kV 630A load break switch
• 1x switch operation handle
• 1x kirk key interlock set (interlock between switch handle and door)
• 1x Visualization window to see switch state (safety glass)
• 1x 15kV 630A breaker
• 1x 7.2kV output receptacle
• 1x “system ground”
• 1x “isolated ground”
• 1x controls
• 2x External light
• Heating and thermostat control