30 kW Tier 4 Final diesel commercial standby generator. Kohler-powered diesel with EPA Tier 4 Final emissions compliance for commercial and institutional applications.
The Kohler 30REOZK4 is a 30-kilowatt EPA Tier 4 Final diesel commercial standby generator powered by a Kohler diesel engine at 1800 RPM. Unlike the standard 30REOZK, this model is certified for both stationary emergency and non-emergency applications, making it suitable for jurisdictions with stricter air quality requirements. The unit features a 4-pole rotating-field alternator with PowerBoost excitation and sustained short-circuit capability up to 300% of rated current.
OnPoint services Tier 4 Final diesel generators across Northern California, where Bay Area Air Quality Management District rules often require Tier 4 certification. The 30REOZK4 adds exhaust aftertreatment components that require periodic inspection as part of the annual PM program.
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Adjust load percent and tank size to estimate runtime. Pre-filled with this model's spec where available.
Estimate runtime on this tank
Estimated runtime
35.6 hours(1.5 days)
Fuel consumption ≈ 2.16 GPH at 75% load. Estimate based on industry-typical 1800 RPM standby curves (≈0.07 GPH/kW at full load). Actual consumption varies by engine, ambient temperature, fuel quality, and tuning.
Service intervals
Manufacturer-recommended intervals for the Kohler 30REOZK4 under standby duty. Field intervals may differ based on load profile, ambient conditions, and fuel quality.
Oil & filter
Every 250 hours or 12 months
Coolant change
Every 2000 hours
Air filter
Every 500 hours
Fuel filter
Every 250 hours
Major overhaul
≈ 8,000 hours
Load bank test
Every 12 months
Common failure modes
What we've seen fail on this platform. Use as a service-planning reference, not a diagnostic — actual failure modes depend heavily on duty cycle and maintenance history.
Component
Symptom
Typical hours
Severity
DPF (Diesel Particulate Filter)
Regen warning, back-pressure fault, power derate
4,380+
moderate
Fuel quality / degradation
Injector fouling, hard starting, reduced power output
4,380+
moderate
Battery (starting)
Slow crank, failed exercise, low voltage alarm
8,760+
minor
Frequently Asked Questions
What makes the 30REOZK4 different from the 30REOZK?
The 30REOZK4 is the EPA Tier 4 Final variant, certified for both stationary emergency and non-emergency applications. It uses exhaust aftertreatment to meet stricter emissions requirements.
What engine is in the Kohler 30REOZK4?
The 30REOZK4 uses a Kohler diesel engine rated at 1800 RPM with EPA Tier 4 Final emissions certification.
