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Medium-voltage switchgear

Pad-mounted Source Transfer (PST) System

Eaton's Cooper Power series PST pad-mounted source transfer (PST) switchgear with iST control is a compact, outdoor, self-contained system ideal for critical, medium-voltage loads. These applications include healthcare facilities, data centers, broadcast studios and production facilities that require highly dependable power for continuous, optimum operation.

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Fully integrated controls package
Resettable overcurrent protection
Source transfer in 6 cycles or less
No-blink restoration
Vacuum interruption
Reliable, low-maintenance service

Core features

  • Provides fast transfer in 6 cycles or less, programmable no-blink parallel restoration through sync check or non-parallel restoration and vacuum interruption
  • Single- or double-sided, self-contained and self-powered deadfront design
  • Offers three-phase switching and fault as well as overcurrent protection
  • Includes SCADA operable, metering and automatic or manual operation
  • Provides communication protocols, Ethernet and fiber
  • Offers a fault block, fully-integrated controls and event recording for post-event diagnostics
  • Available in flexible configurations, one load (Model 6) or two loads (Model 9)

Automatic load transfer and overcurrent protection in a single pad-mounted switchgear unit

Eaton’s Cooper Power series PST pad-mounted source transfer package provides protection against loss of source health as well as overcurrent and fault protection for critical loads. It features deadfront source and tap cable compartments, and a sealed tank.

Advanced metering, control and communications tools

Eaton’s Cooper Power series iST control detects loss of source health and automatically transfers the load between the preferred and alternate sources as well as provides fault detection.
Specifications

Electrical ratings

Maximum design voltage, kV 15 27 38
BIL, kV 95 125 150
1-minute withstand voltage (60 Hz) interrupter and terminators, kV 
 35 40 50
Continuous current (max), A 
 600 600 600
Interrupting current (sym./asym.), kA 
 12/20 
 12/20 
 12/20 
Momentary current 10 cycles (asym.), kA 
 20 20 25
1-second withstand current (sym.), kA 
 12 12 12
Making current (sym.), kA 
 12 12 12
Transformer magnetizing interrupting current, A 
 21 21 21
Cable charging interrupting current, A 
 15 15 20
Capacitive, A 
 10 25 40

Switching and transfer times

Direction of transfer transition Type of return (cycles) First interrupter reaction time* (cycles) Transition time* (cycles)
Preferred to alternate Non-parallel 2.0 to 3.0 5.0 to 6.0
Alternate to preferred Non-parallel
 2.0 to 3.0 5.0 to 6.0
Alternate to preferred Parallel** 5.0 to 6.0 2.0 to 3.0
* Time from expiration of time delay to first opening (or closing) of high-voltage interrupter. Add about 1 cycle to values shown to allow for iST control contact time. 
** Parallel return time does not include sync check time.

Standard features

  • Mild steel construction
  • Cover and doors provide easy access to connections and controls
  • Push-pull handles for manual charging of the stored energy switch operators (when no power is present)
  • Contact position indicator
  • Operation counter, one for each switch
  • Manual trip/close levers lockable in the open position
  • Disconnect switches for internal sensing PTs
  • Spring charged status indicators
  • Liquid sight gauge provides visual indication of liquid level within tank
  • Mineral oil fluid dielectric medium

Optional features

  • Stainless steel construction
  • Motor operation on tap way(s)
  • Additional two-stage auxiliary switches
  • Operation counters on tap ways (model 9 only)
  • Semaphores on tap ways (model 9 only)
  • Fault indicator provisions
  • Drain valve with sampler
  • E200 fluid dielectric medium
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