Caterpillar C27 ACERT

680-800 ekW standby diesel genset on the 27 L ACERT V-12, a liquid mid-size workhorse

Caterpillar C27 ACERT is one of 10 data center generators tracked in the SecondWatt catalogue, each with specifications, lead times and indicative secondary-market pricing.

Caterpillar C27 ACERT genset dossier: 680-800 ekW ratings, verified specs, live used pricing from 137,500 USD, and a buyer inspection checklist.

Why it matters

The 750 kW node is the volume tier of the standby market, and the C27 is one of its two most-traded models. Live asks at 172-399 USD per kW have decoupled from the 60,000-150,000 USD dealer guide band, and CARB-expired units trade at discounts, giving buyers real arbitrage if they can verify condition and tier.

Who buys it

Mid-size data rooms, hospitals meeting NFPA 110, municipalities, water plants, and industrial facilities buy C27s; rental fleets take enclosed units with tanks. The trigger is the same supply squeeze as the large frames: 28-130 week new-unit queues against 2-8 week used delivery, with a deep bench of sub-400-hour units from emergency service.

Role in the data center

Standby unit for mid-size data rooms and edge sites at 750-800 ekW, or distributed N+1 blocks in smaller campuses behind low-voltage ATS gear.

Key specifications

Technical summary

Standby ratings: 750 / 800 ekW (937 / 1000 kVA) Prime ratings: 680 / 725 ekW Engine: C27 ATAAC V-12, 27.03 L Bore x stroke: 137.2 x 152.4 mm, CR 16.5:1 Speed / frequency: 1800 rpm / 60 Hz Voltage: 208-600 V Fuel at 100% / 75% / 50% (750 ekW): 200.3 / 154.4 / 111.2 L/hr Dimensions: 4674 x 1723 x 2162 mm Dry weight: 6622 kg Emissions: EPA Tier 2, emergency stationary Controller: EMCP 4 (4.2B / 4.3 / 4.4) Certifications: UL 2200 packages, CSA

Configurations and options

Used units appear open-skid, in weatherproof enclosures, and with large sub-base tanks (2,000- 4,250 gal documented). Options: EMCP 4.2B through 4.4 controls, 600 V configurations for Canada, jacket water heaters, and battery chargers. Enclosed-with-tank units command the top of the price band.

Compatibility and dependencies

Pairs with 1,000 kVA-class transfer switches, day tanks, and standard low-voltage switchboards. CARB status matters in California: units with expired CARB certification trade at documented discounts and face registration hurdles. EMCP 4 controls integrate directly with modern monitoring.

Pricing and availability

Published price range: $137,500 – $299,000. Trend: up Machinio resale bands by vintage show the ladder: 2006-07 units at 88,900-95,000 USD, 2008-11 at 125,000-180,000 USD, and 2012-14 at 143,834-150,000 USD. Live August 2026 dealer asks run 189,500-299,000 USD for sub-400-hour units, well above the 60,000-150,000 USD dealer guide band published July 2026, tracking the data-center-driven repricing across the CAT line. Lead time, new: 28-78 weeks. Lead time, used or refurbished: 2-8 weeks. Warranty, used: 30-day dealer typical; as-is at auction.

Lifecycle and maintenance

Service cadence: oil and filters at 500 hours or 12 months, fuel filters at 500 hours, air filters at 1,000 hours, coolant at 6,000 hours, and a major overhaul near 20,000 hours per the family service guide and the C27/C32 O&M manual (SEBU8088). Turbo cartridges are stocked aftermarket wear items. Bare C27/C32 engines trade at 25,000-90,000 USD, which anchors repower economics against rebuild quotes.

Common failure points

• Fuel injectors (HEUI-era) — Fouling and hard starts past 4,380 hours on stale fuel
• Turbocharger — Reduced power and oil in intake past 15,000 hours
• Battery bank — Failed starts near 8,760 hours of calendar age
• Wet stacking — Carbon buildup from chronic low-load running
• Generator-end insulation — Low megger readings after storage

Inspection checklist

Hours and vintage — verify meter and build year; the used bench spans 2007-2022 with most units under 400 hours Overhaul position — check against the roughly 20,000-hour major interval for the family Injectors — fouling and hard starts emerge past 4,380 hours on degraded fuel; verify service records Turbocharger — inspect for shaft play and oil in the intake; wear emerges past 15,000 hours on this family Oil analysis — pull a sample; copper flags bearings, silicon flags filtration or coolant intrusion Coolant service — verify within 6,000 hours; inspect pumps and cores Batteries — 24 V bank replacement due near 8,760 hours or 4-5 years Generator end — megger stator; below 5 megohms warrants rewind pricing Controls — confirm EMCP 4 generation and firmware support Emissions nameplate — verify Tier 2 emergency certification; check CARB status on any California-bound unit Enclosure and tank — verify UL 142 tank certification and containment on enclosed units Air filtration — service due at 1,000 hours; inspect housing seals Fuel quality — polish stored fuel; verify 500-hour fuel filter compliance Load test — 4-hour run to 100% of nameplate; reject units that cannot hold 750-800 ekW at temperature Records — complete service logs and any rebuild documentation traceable to serial number

Procurement channels

Wide dealer channel with published prices: Depco, CSDG, Woodstock Power, React Power, and CAT dealer used desks (MacAllister, Ohio Cat, Empire, Toromont). Enclosed-with-tank units clear fastest.

Regional notes

60 Hz North American supply dominates with 600 V Canadian units in the mix (one CAD-priced Toromont listing noted). CARB status splits California-bound value. Export 50 Hz demand is served by other CAT models; the C27 genset line is 60 Hz.