Kohler · REZX Series (Industrial Gaseous)

Kohler 300REZXC

300 kW standby · Natural Gas · Liquid-cooled

300 kW natural gas industrial standby generator. Enclosed gaseous standby with Doosan engine for large commercial and institutional applications.

Kohler Kohler 300REZXC generator — specifications and details
Standby power
300 kW
Voltage options
120/208V, 277/480V
Frequency / Phase
60 Hz · 3-phase
Engine
Doosan D146L · 14.6L
Alternator
Kohler Brushless, Permanent-Magnet
CommercialHealthcareGovernmentindustrial-light
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Overview#

The Kohler 300REZXC is a 300-kilowatt natural gas industrial standby generator in an enclosed configuration. Rated at 230-300 kW standby depending on voltage, it uses a Doosan engine paired with a brushless permanent-magnet alternator at 1800 RPM. This unit is EPA certified for stationary emergency applications and features hurricane-rated enclosure options with a 181 mph wind load rating.

Gaseous vs diesel at 300 kW#

At 300 kW, natural gas generators offer a compelling alternative to diesel: no on-site fuel storage, no SPCC compliance, no fuel degradation, and effectively unlimited runtime on utility gas. The primary risk is that natural gas supply depends on the utility pipeline remaining operational during the outage event. For facilities where the gas utility is historically reliable, natural gas standby is an excellent choice at this power level.

Our service experience#

PowerGen provides installation, maintenance, and emergency service for Kohler gaseous generators throughout Northern California. Natural gas units in the 300 kW class require attention to gas pressure regulation and fuel train components in addition to standard ignition and coolant service. We structure PM programs accordingly.

Engineering specifications

Physical

Length
137.8 in
Width
68.9 in
Height
84.6 in
Wet weight
7,055 lb

Fuel system & runtime

NG required pressure
7 in WC

Photos

Kohler 300REZXC — product photo

Documents & downloads

Spec sheets & manuals

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Configure your Kohler 300REZXC

Lock the enclosure, fuel system, transfer switch, and add-ons — we'll confirm pricing, availability, and lead time within one business day. Prefer a free-form quote? That option is still here.

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Estimate runtime for the Kohler 300REZXC

Adjust load percent and tank size to estimate runtime. Pre-filled with this model's spec where available.

Estimate runtime on this tank

Fuel demand at 75% load

3,150,000 BTU/hr≈ 3150.0 cf/min @ 1,000 BTU/cf

On utility natural gas the runtime is generally unlimited provided the supply line and meter can deliver this BTU/hr at the engine's required inlet pressure (typically 5–14" WC residential, up to 5 psi commercial). Confirm against the OEM's published fuel-pressure spec.

Service intervals

Manufacturer-recommended intervals for the Kohler 300REZXC 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 3000 hours
Air filter
Every 500 hours
Spark plugs
Every 500 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.

ComponentSymptomTypical hoursSeverity
Spark plugs / ignitionMisfire under load, cylinder dropout codes, rough idle500+minor
Turbocharger sealsOil in intake, blue smoke, boost pressure loss10,000+moderate
Fuel pressure regulator / vaporizerHard starting, gas pressure fault, erratic idle8,000+moderate
Battery (starting)Slow crank, failed exercise8,760+minor

Frequently Asked Questions

What is the standby rating of the Kohler 300REZXC?
The 300REZXC is rated 230-300 kW standby (230-325 kVA) depending on voltage configuration, operating on natural gas at 60 Hz.
What fuel does the Kohler 300REZXC use?
The 300REZXC operates on natural gas. It is purpose-built for pipeline natural gas applications, offering unlimited runtime as long as the gas utility remains operational.
What is the difference between RZX and REZX models?
RZX designates the open-frame (skid-mounted) configuration, while REZX is the enclosed (sound-attenuated or weather-protective) version. Both use the same engine-alternator package; the difference is the enclosure.

Compatible equipment

Engine

Transfer switches

More in the REZX Series (Industrial Gaseous)

Kohler REZX enclosed gaseous gensets from 190 to 500 kW — LPG, natural gas, or dual-fuel with Doosan power.

View all 12models in this series →

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