The Coolspool Hybrid 300 is a 28V DC ground power unit, (GPU), designed for use in aircraft hangars, congested ramps and busy gate areas where space is limited. Regional and commuter operators with frequent turn-rounds, and FBOs requiring continuous DC power for avionics in the hangar or power for starting on the ramp, will appreciate the compactness and versatility of this Powervamp GPU.

  • 5000 peak amps
  • 300A continuous current
  • Support 24V/26V and 28.5V DC systems
  • Instant turbine starting power exceeding 2000 amps
  • Hangar feature without diesel operation
  • Emission compliant Kubota engine
  • 110V/230V 50/60Hz power outlet
  • -20 to +50°C operating range

Product Information

Product Information

Powered by a tier 4 emission compliant 3-cylinder water-cooled Kubota diesel engine, the Coolspool Hybrid 300 is the latest model of Powervamp’s compact low cost diesel GPU. Developed for use by DC aircraft operators and FBOs, all or whom require continuous ripple free power during maintenance work in the hangar or on the ramp during turn-rounds, no other GPU delivers the versatility and convenience of Powervamp’s Coolspool Hybrid 300.

This compact and efficient diesel GPU will deliver the continuous 28V power of a TRU from a utility source while in the hangar or instantly switch to self- contained super clean tier 4 diesel power.

The Hybrid 300 features as standard single phase AC power for ancillary equipment such as vacuum cleaners, work lights or power tools. 3 x 100 amp output 28V DC power supplies connected in parallel provide up to 300 amps of continuous power while providing a useful redundancy feature at reduced output.

Instant power exceeding 2200 amps, is available for turbine starting. During line ops or maintenance where power above 300 amps is required for example during hydraulic systems operations, the large capacity of the ultra high discharge batteries seamlessly delivers the required amperage. Batteries are recharged automatically from either a utility power source or from the Hybrid diesel.

Powervamp first conceived the idea of hybrid power in 1995 as a solution for the MOD’s ab initio Helicopter flying school. Using a small gasoline gen-set feeding a 40 amp 28V DC power supply through an ultra high discharge power pack provided the continuous power during the long pre-flight checks of new students. Previously this had depleted the on-board batteries and consistently compromised the daily mass starts of the MOD’s fleet of 30 training helicopters.

The latest Coolspool Hybrid 300 delivers 300A continuous power at 28V DC from its diesel generator or from any 3-phase utility supply which allows it to be used in the hangar or any confined space.

110V or 220V AC 50/60Hz** single phase power can be selected to provide power for ancillary equipment such as lights, work tools or aircraft cleaning equipment. A selector switch directs generator output to 28V DC or 110V/230V single phase.

The Coolspool Hybrid 300 is available in various configurations and has been in series production for over 17 years.

This latest model features simple controls with solid-state electrics and multi-function monitoring. FBOs, regional airlines, and operators can now acquire DC power at a fraction of the cost of a conventional diesel GPU up to 4 times the size and engine capacity of Powervamp’s Hybrid 300.

** Depending of specification at time of order.

Supplied with:

4m Hard Wired Nato Lead

4m Hard Wired Nato Lead

Wheel Brake System

Wheel Brake System

Powervamp spare wheel for coolspool410 and hybrid300

Spare Wheel

Typical power plant*

PT6C-67, ALF 502, TPE331, TFE 731, AE3007A, or power plants of a similar specification

Scammer 300

Pre-flights: All DC business jets, small commuters. Air-con: up to 400 amps continuous, peak to 1400 amps, short term 200–400 amps until voltage limit warning.

Turbine starting: All DC business jets

All Features

All Features

  • Can operate as a TRU from a 3-phase utility supply allowing full performance within hangars or any confined area.
  • Support 24/26V and 28.5V DC systems
  • 300 amps continuous output at 28.5V DC
  • 110V/230V 50/60Hz power outlets for ramp/hanger use
  • 5000 peak amps
  • Easy to manoeuvre and transport between operational bases
  • Ability to recharge external ground power units via power output socket
  • Simple to service and maintain
  • Modular designs to suit operator requirements
  • Reverse current protection
  • Reverse polarity protection
  • Complies with ISO 6858

Technical Specs

Technical Specifications

Peak amps 5000A
Nominal voltage Batteries 24V DC/power supply 28V DC
Standing voltage 25.6V DC
Amp/hour capacity 228Ah (other options available)
Operating temp -30°C to +50°C (-22°F to 122°F)/td>
Case Galvanised steel frame with alloy panels
Control panel LCD screen provides detailed information of different parameters. Large rubber ON/OFF buttons for easy operation
Aircraft cable Different options available: 4m (13ft), 6m (20ft) and 8m (26ft) with heavy-duty rubber Nato connector
Output current 300A continuous
Input voltage 190–200V AC or 380–415V AC / 50–60Hz (only in Mains mode with the engine turned Off)
Input current 32A @ 400V AC; 32A @ 200V AC/ 3-phase (only in Mains mode with the engine turned Off)
Cooling Forced ventilation
Forklift points 2 forklifting points on both sides
Fuel type Diesel
Fuel tank capacity 33 litres (7 gallons)
Aux output 115V AC 60Hz / 230V AC 50Hz
Dimensions L 1900mm (75in) W 970mm (38in) H 1130mm (45in)
Weight 538kg (1186lb) for a dry unit with 4m output cable


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