The Challenge
Powerbox was approached by an Australian railway operator to design and manufacture a DC/AC inverter. This was needed for on-board AC power requirements in their fleet of diesel powered locomotives.

The inverter was to be used to power on-board driver amenities which could vary between kettles, hand dryers, refrigerators and microwaves.

Australian long-haul fleets encounter some of the world’s harshest environmental conditions.

These conditions may include, but are not limited to:
• Shock and vibration
• Input spikes
• Extreme temperatures
• Humidity
• Iron Ore / Coal Dust

We took all of these conditions into consideration when designing our product to ensure reliability.

The Solution
Powerbox developed the PBSP-74O-G DC-AC inverter. The PBSP-74O-G is a true sinewave inverter, built specifically for railway applications. The inverter operates from a nominal 74V DC power source and produces a single phase 240V ac 50Hz output. The inverter can operate loads of up to 4KW continuously, loads up to 5KW for 30 minutes, and surge loads of up to 12 KW for up to 3 seconds. This high-surge capability allows the inverter to be used for loads with high surge currents such as motors and microwave ovens.

The PBSP-74O-G employs the latest power MOSFET switching technology combined with embedded microprocessor control to produce very low output distortion -less than 3% THD, at very high efficiencies (95% peak).

The design includes comprehensive protection features. Input over-voltage and under-voltage cut-outs turn the inverter off in the event the input voltage goes outside of the normal input voltage overloads and short circuits.

The inverter is protected against high ambient temperatures with the automatic over-temperature shutdown.

Added Value
Over the past 15 years, the PBSP-74O-G inverter has proven to be highly reliable and has resulted in less down time in rail operators' fleets due to unit failures. Our aftermarket support team have been working closely with rail operators in managing a stock of rotatable units which come back for routine servicing and repairs, when a locomotive is taken out of service for maintenance. The ability to service units, rather than replace them has saved a huge amount of expenditure over the period.

Visit our product page for more information about our PBSP-74O-G product range or contact us to talk about your specific project requirements.