ABB UniGear ZS2 air-insulated switchgear (36 kV)
ABB UniGear ZS2, the 36 kV metal-clad line whose class carries the longest switchgear lead times of all
ABB UniGear ZS2 air-insulated switchgear (36 kV) is one of 41 data center switchgear tracked in the SecondWatt catalogue, each with specifications, lead times and indicative secondary-market pricing.
ABB UniGear ZS2 dossier: 36 kV metal-clad switchgear at 2,500 A and 31.5 kA, cancelled-project surplus evidence, 78-104 week leads, inspection points.
Why it matters
At 78-104 week new-build leads, a crated 36 kV lineup with spares is nearly irreplaceable inventory: whoever finds it first controls a project schedule. ZS2's single documented surplus lot proves the sourcing thesis and the intelligence gap, since no marketplace tracks 36 kV-class surplus systematically.
Who buys it
Utilities and industrial plants distributing at 33-36 kV specify ZS2, with renewables collection and large-campus intake the growth duties. Surplus buyers are EPCs hunting cancelled-project lots to beat two-year leads; the Salvex lot shows such inventory exists but clears through auction channels, not dealer shelves.
Role in the data center
33-36 kV campus intake and renewables-collection switching for IEC-market projects; surplus lots are schedule insurance against the market's longest switchgear leads.
Pricing and availability
Trend: up Lead time, new: 78-104 weeks (38 kV class). Lead time, used or refurbished: Auction-lot dependent. Warranty, used: 1-year typical from reconditioning dealers.
Lifecycle and maintenance
Metal-clad MV switchgear routinely serves 40+ years: vacuum interrupters rated for 10,000-30,000 operations far outlast the mechanical duty standby service imposes, so lineup life is governed by insulation condition and relay/controls vintage. Breakers recondition readily and trade as units, while lineups modernize in place with digital relays and retrofit breakers. ANSI/NETA MTS acceptance testing at purchase plus PD surveys in service are the condition gates.
Common failure points
- Vacuum interrupters — Loss of vacuum ends interrupting capability with no external sign
- Insulation tracking and PD — Partial discharge across dusty or damp insulation progressing to flashover
- Racking and interlocks — Damaged racking screws and defeated interlocks from forced operation
- Protection relays — Obsolete or drifted relays mis-operate under fault
- Instrument transformers — CT/VT failures disable metering and protection inputs
- Space heater failure — Condensation-driven tracking in unheated outdoor or humid gear
Inspection checklist
Vacuum integrity — hipot test each interrupter per OEM procedure (e.g., 36 kV test on 15 kV class) Insulation resistance — megger bus and breakers at 2,500-5,000 V; compare to ANSI/NETA MTS tables Contact resistance — micro-ohm each pole; investigate imbalance beyond 50% between phases Partial discharge — ultrasonic and TEV survey; investigate any reading 6 dB above baseline Contact erosion — measure vacuum interrupter erosion marks against the OEM wear allowance Racking mechanism — cycle connect/test/disconnect positions 3 times each; verify interlocks and shutters Mechanism timing — verify open/close times; closing beyond 5 cycles flags mechanism trouble Bus insulation — inspect epoxy and boots for tracking or corona; clean and torque joints Instrument transformers — verify CT/VT ratios, insulation, and fusing Protection relays — test to calibration cycle; electromechanical relays need 1-2 year intervals Arc rating — confirm arc-resistant construction class (IEEE C37.20.7 Type 2B) matches the installation Heaters — verify space heaters work; condensation drives tracking failures in unheated gear Nameplate — confirm voltage class, BIL (60-150 kV by class), and interrupting rating against the application Standards — verify IEEE C37.20.2 construction and UL/CSA labels; run ANSI/NETA MTS acceptance tests Records — factory test report, maintenance history, and operation counts; missing history reprices as-is