Overview#
The MQ Power DCA-70 WhisperWatt is a 70 kVA (56 kW prime / 62 kW standby) portable diesel generator — the mid-range workhorse of rental fleets and a Tier 4 Final unit using DEF/SCR aftertreatment. Multiquip rates it at 65 dBA at 23 feet, matching the sound level of the smaller DCA-25.
DEF / SCR aftertreatment#
The DCA-70 uses DEF (Diesel Exhaust Fluid) for emissions compliance. Practical considerations:
- 7.4-gallon DEF tank (28 L) per Multiquip's data sheet
- DEF quality matters — contaminated or old DEF causes SCR faults and power derating
- Cold weather: DEF freezes at about 12°F (-11°C)
- Don't ignore DEF warnings — the ECU will progressively derate power output if DEF runs empty
Common applications#
- Large construction sites (tower cranes, welding, HVAC commissioning)
- Multi-day outdoor events and festivals
- Commercial emergency backup (retail, restaurants during utility work)
- Film/TV production with significant lighting loads
- Temporary power for building commissioning
Our service experience#
The DCA-70 is one of the most commonly rented generators for commercial temporary power in our territory. The Isuzu BR-4JJ1X engine is reliable but the Tier 4 Final aftertreatment (DEF/SCR) adds a maintenance dimension that operators need to understand. The most common issue we see: DEF-related fault codes from operators ignoring low-DEF warnings or using contaminated DEF. We train our rental customers on DEF handling as part of delivery orientation.
