400 kVA (320 kW prime) portable diesel generator. The largest WhisperWatt Super-Silent for major construction, infrastructure, and large-scale emergency power.
The MQ Power DCA-400 WhisperWatt is a 400 kVA (320 kW prime / 336 kW standby) portable diesel generator powered by an Isuzu BG-6WG1X 6-cylinder. It is the top of the WhisperWatt Super-Silent towable lineup — above the DCA-300 and suited for applications requiring sustained 250-320 kW at a portable location with meaningful sound attenuation.
Two things set the DCA-400 apart from the DCA-300: CARB compliance (California job sites) and the Isuzu platform (broader rental fleet familiarity in North America versus the JD-powered DCA-300).
We deploy DCA-400 units for the largest temporary power requirements in our market — major construction projects, extended utility outages affecting commercial facilities, and large public events requiring a single large portable rather than paralleled smaller units. At this size, the technical sophistication of the Tier 4 Final aftertreatment system means pre-delivery briefings and planned service intervals are more important than with smaller units. We recommend establishing a DEF delivery cadence as part of the deployment plan, not as an afterthought.
Engineering specifications
Physical
Length
181 in
Width
59 in
Height
100 in
Dry weight
13,184 lb
Acoustic
Sound @ 7m, full load
69 dBA
Enclosure
Sound-attenuated
Fuel system & runtime
Integral fuel tank
405 gal
Fuel use @ full load
22.5 GPH
Fuel use @ 75% load
17.3 GPH
Fuel use @ 50% load
12.2 GPH
Request a quote
Get pricing & lead time on the MQ Power DCA-400 WhisperWatt
Tell us about the application — kW, voltage, application, install timeline — and we'll respond within one business day with budgetary pricing, lead time, and any sizing notes.
Estimate runtime for the MQ Power DCA-400 WhisperWatt
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
23.3 hours(1.0 days)
Fuel consumption ≈ 17.36 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 MQ Power DCA-400 WhisperWatt under standby duty. Field intervals may differ based on load profile, ambient conditions, and fuel quality.
Oil & filter
Every 500 hours or 12 months
Air filter
Every 1000 hours
Fuel filter
Every 500 hours
Major overhaul
≈ 20,000 hours
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
DEF system (SCR)
DEF fault codes, derate warning, progressive power derate
3,000+
moderate
DPF (Diesel Particulate Filter)
Regen warning, back-pressure fault, power derate
4,380+
moderate
Turbocharger
Reduced power, excessive smoke, turbo whine
15,000+
moderate
Fuel quality
Injector fouling, filter clogging at sustained high load
1,000+
minor
Frequently Asked Questions
What engine is in the DCA-400?
An Isuzu BG-6WG1X — a 6-cylinder turbocharged diesel rated at 512 HP for generator drive. EPA Tier 4 Final certified and CARB compliant, with DPF and SCR aftertreatment requiring DEF.
Is the DCA-400 CARB compliant?
Yes. The DCA400SSI4F carries California Air Resources Board (CARB) compliance, making it usable on California job sites where standard EPA Tier 4 Final units cannot operate. This is a significant differentiator for rental fleets serving California.
How does the DCA-400 compare to the DCA-300?
The DCA-400 (320 kW prime) adds 33% more output over the DCA-300 (240 kW prime) using an Isuzu 6-cylinder rather than John Deere. The DCA-400 also carries CARB certification. At 69 dBA vs 72 dBA, the DCA-400 is actually quieter per the WhisperWatt enclosure spec.
What's the DCA-400 used for?
Major construction (high-rise, data centers, hospital construction), large-scale temporary power for events requiring 250-320 kW sustained, disaster recovery, and emergency backup for commercial facilities with large critical loads.
Similar models
M
MQ Power
New
MQ Power DCA-300 WhisperWatt
264 kW standby · Diesel · Liquid-cooled
300 kVA (240 kW prime) portable diesel generator. Large WhisperWatt for major construction, events, and emergency commercial power.
Tier 4 Final3-phaseconstruction-majorrental-fleet
M
MQ Power
New
MQ Power DCA-150 WhisperWatt
132 kW standby · Diesel · Liquid-cooled
150 kVA (120 kW prime) portable diesel generator. John Deere-powered WhisperWatt Super-Silent for major construction, large events, and emergency commercial power.