Portable GPU handle

GPU fork for portable power supplies

Model 3328 Special

Mobile 28V Aircraft Engine Start Pack


The START PAC® GPU model 3328 Special is designed to perform repeated superior starting functions for large turbine engines, including the Garrett and Honeywell TPE331. It is rated at 2800 peak starting amps and is a full 28 Volt battery pack (28.5 Volts to be exact, 30.5 volts at rest).


STARTING UNIT model reference3328 Special
Battery typeLead acid
Voltage28 VDC
Peak Current2800 A
Capacity @10 Amp Rate84 Ah
Total Weight225lbs / 102kg
Dimensions – Length x Width x Height38″ x 21″ x 20″ 96.5 x 53.3 x 50.8 cm
Charger typeBuilt in
Float type charger input (must be specified on order)110 VAC 50/60 hertz 220 VAC 50/60 hertz
Charging time range30 minutes to 4 hours

Due to the extra starting power provided by the 28.5 Volt batteries, turbine engines will experience faster and cooler engine start than most ship’s aircraft batteries (the turbine is spooled to more revolutions per second before fuel is injected). Thus, turbine life will be extended because there is less stress on the starter and other engine components. This will preserve the aircraft’s costly batteries and help lower operating costs. Your airborne, on-board battery can then be saved for emergency use only. As a START PAC® secures all your engine starts, this unit will ensure that you have no downtime. It can be used in remote locations using battery power to give extended time for cockpit maintenance checkout. Its large battery capacity will allow extended usage time when no AC power source is available. Additionally, this unit can be configured for 110 Volt or 220 Volt AC input.

The 3328 Special is coated in an environmentally responsible, low VOC powder coating, which protects it from wear, tear and extreme weather conditions. Additionally, an all-weather cover is also available as an option to protect this unit further from inclement weather and to gain the maximum performance and product life.

Load vs. Time (click to view larger)

Voltage Drop vs. Load (click to view larger)

The following dimensions apply to each of the 3300s:
38″x21″x20″ Handle Height 48″

Please handle this unit in a responsible manner. START PAC™ is not responsible for damages caused by misuse or neglect.

Always recharge the GPU until the green light appears and leave it plugged in when not in use. If a heater is installed, turn the unit off but leave it plugged in.

Avoid discharging the batteries completely so as to avoid damaging the cells which can result in reduced capacity and premature battery failure.

Always recharge batteries soon after use.

There are approximately thirty 110 volt and thirty 220 volt NEMA plugs in use on this unit. Additionally, customers will have differing receptacles at their hangars and MRO facilities and may require specific AC cord lengths in order to meet their requirements. As a result of this, we do not automatically provide AC power cords. However, if you provide the NEMA plug number and specify the AC power cord length you require, for a small fee we will build a cord to be shipped with your unit.


START PAC has a wide selection of ground power units and starting units for portable power and portable power supplies, such as the classic yellow aircraft starter unit. Browse our website to discover our extensive product line or visit our tutorial section to learn more about our power supply products. Have a question or need assistance with your order? START PAC provides customer service support via phone and email, making it extremely easy to find the yellow GPU or railroad locomotive starter unit you’re looking for.

All START PAC™ products come with a 1-year warranty on workmanship and materials.*

Please handle this unit in a responsible manner. START PAC™ is not responsible for damages caused by misuse or neglect.


Need Assistance?

START PAC offers a wide selection of power suppliesstarting units and combination Aircraft Ground Power Units (GPU). Browse our website to read about our extensive product line or visit our tutorial section to gain a more technical insight into our products. If you have a question or need help finding the right product for your aircraft, locomotive or vehicle, START PAC provides customer service support via phone and email. One of our friendly and knowledgeable experts will guide you to the product suited to your specific needs. If – for whatever reason – you are unhappy with your START PAC product, simply send return the unit to us for a full refund.

Why buy from START PAC®?

Made in the USA and developed with the latest state-of-the-art battery and power management technology, our products are trusted the world over. START PAC power supplies are built for heavy duty application and are designed to withstand all environments, however tough. START PAC boasts superior technical and after sales support thanks to our long standing industry experience and our passion for the industries in which we work. START PAC offers unparalleled value for money and fast global shipping via our international dealership network.

*Batteries are cycle-dependent and are therefore not covered under this warranty.