General Equipment Identity

• Name of Equipment: The equipment is identified as the Ground Power Unit (GPU), specifically Model C690. The Houchin 690 range is designed to provide ground power servicing for the AC and DC systems of all types of aircraft.
• Manufacturer: The manufacturer is HOUCHIN.
• Manufacturer Date: A specific date of manufacture for an individual unit is not provided in these sources. The operations and maintenance manual supporting the Model C690 bears a publication date of May 2006.
• Serial Number: 778-B
• Condition (refurbished)
• Working Hours: 270 HOURS

Specific Technical Data (Model Variants)

The C690 unit utilizes a Cummins “B” series 6-cylinder water-cooled diesel engine and is detailed in the sources across three power variants:

GPU Model 690/90: Continuous AC Rating is 90kVA at a power factor of 0.8 – 1.0 lagging. It uses a Cummins engine type 6BT5.9C-152.

Common Outputs and Physical Data:

• AC Output: 200V AC, 400Hz, 3-Phase 4-wire.
• DC Output: If fitted, the continuous rating is 800A and the intermittent rating is 2500A.
• Weight: The approximate weight for a dual voltage unit is 2480 Kg.
• Overall Dimensions (Towbar Down): Length is 4450mm; Width is 1755mm; Height is 1690mm.

The Houchin Ground Power Unit (GPU) Model C690 is designed to provide ground power servicing facilities for both the alternating current (AC) and direct current (DC) systems of all aircraft types. The equipment is typically mounted on a four-wheel trailer enclosed within a weatherproof canopy engineered for maximum access and noise attenuation.

Engine and Powerplant Details

The unit is powered by a Cummins “B” series 6-cylinder water-cooled diesel engine. For the GPU Model 690/140, the specific engine type is 6BTA5.9C200.

Engine Specifications:

• Rated Speed: 2400 rpm.
• Electronic Speed Governor: GAC 5111.
• Oil Pressure: Greater than 30 lb/in² (2.2 kg/cm²) at 2400 rpm.
• Protection Systems: Automatic shutdown devices are installed to protect the engine against events such as low oil pressure (shutdown at 10 lb/in² or 0.7 kg/cm²), high water temperature (shutdown at 99 degC), and overspeed (automatic shutdown at 2640 rpm).
• Cooling System: Recirculating type with thermostatic control, pressurised to 7 lb/in² (0.5 kg/cm²).

Fluid Capacities:

• Engine Lubricating Oil System: 20 litres.
• Cooling System: 31 litres.
• Fuel Tank Capacity: 275 litres.

Alternator and AC Output

The unit utilizes a Houchin brushless 3-phase alternator driven through a steel drive disc coupling. The alternator itself is a static-armature brushless machine wound to deliver an output of 200V line, 400Hz, 3-phase, 4-wire when running at 2400 rpm. Excitation current is controlled by an automatic voltage regulator (AVR). Cooling is achieved via a centrifugal fan mounted on a carrier ring at the bearing end of the rotor.

AC Ratings (GPU Model 690/140):

• Continuous AC Rating: 140 kVA at a power factor of 0.8 – 1.0 lagging.
• Intermittent AC Rating: 161 kVA at 0.8 power factor lagging for 1 hour in 12 at normal temperature pressure.

The unit is capable of delivering its reserve rated output in ambient temperatures up to +44 deg C and altitudes up to 3000 ft/1000m.

Standard AC Cable(s): The standard AC output cable is 7.6m effective length, 4-core, 70mm², and terminates in a standard 6-pin aircraft connector. Optional lengths of 10m and 15m are also specified.

DC Output (Optional Transformer Rectifier Unit – TRU)

An optional 28V DC Transformer Rectifier Unit (TRU) assembly can be fitted beneath the hinged control panel support, operating from the 200V 400Hz output of the alternator. If the 28V DC supply is in use, the 400Hz/200V AC supply is unavailable for external use.

DC Ratings (When fitted):

• Continuous Rating: 800A.
• Intermittent Rating: 2500A.
• Optional Current Limit Control: If fitted, the output current of the TRU can be limited within the range of 500A – 1500A.

An optional 28V DC output cable, 10m/33ft long, 4-core, 70mm², terminating in a standard 3-pin connector, may be fitted.

Physical and Towing Dimensions

The equipment is mounted on a four-wheel trailer featuring semi-elliptical leaf spring suspension, turntable steering, and pneumatic tyres. The fuel tank is transversely mounted underneath the trailer.

Overall Dimensions:

• Length (towbar up): 3606 mm.
• Length (towbar down): 4450 mm.
• Width: 1755 mm.
• Height: 1690 mm.
• Wheelbase: 1975 mm.
• Weight (Dual Voltage Unit, approx.): 2480 Kg.
• Maximum Towing Speed: 25 km/hr (15 mph).

The noise level produced by the unit is reduced to 85 dBA +/- 3 dBA at 4 metres.