28V DC SC Single-Core Aircraft Ground Power Cable (1 × (120 mm² + 4 × 1.0 mm²)) is a cold-flexible, halogen-free airport ground support equipment (GSE) power cable engineered for mobile diesel/battery 28.5 V DC ground power units (GPUs) and hangar pit converters. Its dual-extruded red inner + high-visibility yellow outer polyurethane (PUR) jacket resists concrete apron dragging, Jet A-1 fuel, hydraulic fluids, and sub-zero ramp handling down to -40°C.
1. Application Scope & Airport GPU Cable Selection Matrix
Aircraft operating on 28 V DC electrical buses require exceptionally low-resistance flexible ground feeders capable of carrying continuous avionics/maintenance loads (300-600 A) as well as brief turbine engine-starting peaks without excessive voltage drop across ramp runs:
- Mobile Diesel & Lithium Battery 28.5 V DC GPU Carts: Paired single-core positive/negative ramp assemblies terminating into standard 3-pin oval NATO / ISO 6858
28 V DCaircraft plugs. - Regional Turboprops, Business Jets & Helicopters: Turnaround avionics power, pre-flight cabin conditioning, and direct turbine starter-generator cranking.
- MRO Hangar Floor Pits & Boom Reels: Flexible drop or motorized reel leads resistant to Skydrol hydraulic fluid, lubricating oils, and de-icing chemicals.
- Military Flight-Line Support Equipment: Sub-zero arctic ramp deployment (
-40°Cflexible,-50°Cfixed) and high-visibility FOD-inspected apron routing.
| TEBAOFLEX Airport GPU Series | Rated System | Core Architecture | Primary Aircraft / GSE Duty |
|---|---|---|---|
| 28V DC SC Single-Core GPU Cable (This Page) | 28 V DC | 1 × (120 mm² + 4 × 1.0 mm²) | Single-pole modular paired leads for turboprop, business jet & helicopter GPUs |
| 270V DC Multi-Core PUR Aircraft GPU Cable | 270 V DC | Multi-core DC power + pilot/interlock cores | High-voltage DC military aircraft & advanced hangar test benches |
| 400Hz Airport Ground Power Cable (115/200 V AC) | 115/200 V, 400 Hz | Symmetrical 7-core low-reactance + control cores | Passenger boarding bridges (PBB), apron pits & commercial jet GPUs |
| GP 400 SC / QF PUR 400 Hz Aircraft GPU Cable | 115/200 V, 400 Hz | Quad/7-core low-voltage-drop PUR assembly | Mobile 400 Hz GPU carts & coiled/reeling airport stingers |
View our broader Industrial & Control Cables catalog for specialized ground-support and reeling cables.
2. Cable Construction & Visual Wear-Indicator Sheath
As shown in the stepped studio cutaway above, every layer of the 28V DC SC construction is built around corrosion resistance, cold-weather handling, and ramp inspection safety:
+28 V plug interlock, remote voltage-drop sensing, and plug-head status pushbuttons/LEDs.120 mm² + 4 × 1.0 mm² core bundle and serving as a high-contrast visual wear-indicator layer.3. Technical Parameters & Current-Carrying Characteristics
All electrical, mechanical, and thermal values below preserve the documented factory specification for the 28V DC SC single-core GPU design:
| Parameter | Documented Value | Test / Engineering Basis |
|---|---|---|
| Nominal Voltage (Uo/U) | 28 V DC (compatible with standard 28.5 V DC GPU regulated output) | ISO 6858 / GSE DC supply |
| AC Factory Test Voltage | 600 V, 50 Hz (core to core) | Routine dielectric test |
| Conductor Stranding | Fine-stranded tinned copper, Class 5 | IEC 60228 / DIN VDE 0295 |
| Operating Temperature Range | -50°C to +90°C fixed installation; -40°C to +90°C flexible ramp duty | Cold-bend & thermal aging |
| Minimum Bending Radius | 4 × D (approx. 92 mm) fixed; 6 × D (approx. 138 mm) flexible handling | GSE coiling & reel guidance |
| Halogen-Free Compliance | Halogen-free polyurethane compound system | IEC 60754-1 |
| Continuous Current (+50°C Amb.) | 344 A separately laid in free air up to +50°C ambient | Hot-apron continuous rating |
| Reference Current (+20°C, 80% Curve) | 500 A at +20°C ambient on the 80% derating curve | Standard cyclic ramp duty |
| Reference Current (+20°C, 100% Curve) | 600 A at +20°C ambient on the 100% curve, separately laid in free air | Open free-air single core |
4. Dimensional Data & 28.5 V DC Ramp Assembly Configurations
Row 28V-DC-SC lists the exact factory unit metrics per single cable; the two assembly rows below illustrate how GSE manufacturers configure paired single-pole leads to meet voltage-drop and peak starting current targets:
| Part / Assembly Code | Configuration | Unit Outer Dia. (mm) | Copper Figure (kg/km) | Approx. Cable Weight (kg/km) | Max. DC Resistance @ 20°C (Ω/km) | Typical 28.5 V GPU Duty |
|---|---|---|---|---|---|---|
28V-DC-SC (Single Cable) | 1 × (120 mm² + 4 × 1.0 mm²) | 21.0 – 23.0 | 1,296 | 1,339 | 120 mm²: 0.164; 1.0 mm²: 20.0 | Single pole (+ or -) modular replacement lead |
28V-DC-SC-2P120 (2-Cable Pair) | 2 × [1 × (120 + 4×1.0 mm²)] (+ / -) | 2 × (21.0 – 23.0) | 2,592 (pair) | 2,678 (pair) | 0.164 per pole (0.328 loop) | 300-600 A continuous GPU carts (typical 8-15 m stinger) |
28V-DC-SC-4P240 (Parallel Quad) | 4 × [1 × (120 + 4×1.0 mm²)] (2+/2-) | 4 × (21.0 – 23.0) | 5,184 (set) | 5,356 (set) | 0.082 per pole (0.164 loop) | 600 A continuous / 1,500-2,000 A heavy turbine start |
DC Voltage-Drop Calculation Tip: On a 28.5 V DC bus, total loop resistance (positive lead + negative return = 0.328 Ω/km at 20°C for a single 120 mm² pair) produces approx. 1.97 V drop over a 15 m GPU stinger at 400 A. Enable remote voltage-drop compensation via the 1.0 mm² sense cores or parallel two 28V-DC-SC leads per pole on long ramp runs.
5. Frequently Asked Engineering Questions
How is a single-core 28V DC SC cable used to form a complete positive/negative aircraft GPU lead?
Because 28.5 V DC aircraft ground power plugs (NATO Stanag 3302 / ISO 6858 3-pin oval receptacles) carry high DC currents and brief turbine-starting surges, ground-support integrators pair two flexible single-core cables (one for +28 V DC and one for 0 V DC negative return, strapped together along the ramp run) terminating into the 3-pin aircraft plug, using the integrated 1.0 mm² cores for plug-interlock and remote voltage-drop sensing.
How does the red inner + yellow outer PUR dual sheath act as a ramp safety wear indicator?
Airport GPU cables are dragged repeatedly across rough concrete and asphalt aprons and exposed to Jet A-1 fuel, hydraulic fluid, and runway de-icing glycols. High-visibility yellow outer PUR alerts ramp vehicles; if concrete abrasion wears through the outer yellow layer, the contrasting red PUR inner sheath becomes immediately visible during daily GSE walkaround checks before conductor insulation is exposed.
What continuous and turbine-starting surge currents can the 120 mm² 28V DC SC cable handle?
Separately laid in free air, the 120 mm² Class 5 tinned copper core is rated at 344 A continuous up to +50°C ambient, 500 A at +20°C on the 80% derating curve, and 600 A at +20°C on the 100% curve. For 30-to-60-second turboprop or helicopter engine-starting surges (1,200 A to 1,800 A), operators run short single-120 mm² pairs or parallel twin-120 mm² (240 mm² per pole) sets.
Why are four 1.0 mm² control cores integrated inside the single-core 28V DC cable?
The four colour-coded (red, black, green, yellow) 1.0 mm² Class 5 tinned copper cores wire the third small interlock/pilot pin of standard 28 V DC aircraft plugs (opening the GPU contactor before main power pins disengage to prevent arc flash), remote voltage sensing at the aircraft receptacle, and plug-head pushbutton/LED controls.
When should I choose 28V DC SC vs. 270V DC or 400 Hz AC aircraft ground power cables?
Choose 28V DC SC for regional turboprops, business jets, general aviation, and helicopters equipped with 28 V DC buses. Choose 400Hz Airport Ground Power Cable or GP 400 SF DR PUR 400 Hz Cable for commercial airliners, and choose 270V DC Multi-Core PUR Cable for 270 V DC military aircraft.
Specify 28V DC SC Aircraft Ground Power Cable for Your GPU Fleet
Send your continuous/starting current rating, stinger length, ambient ramp temperature, and bulk drum or cut-length quantity. TEBAOFLEX will provide a technical review and direct factory quotation within 24 hours.
