Belize's Caye Caulker Submarine Power Interconnection Project

Project Background

In 2023–2025, Belize Electricity Limited (BEL) executed a landmark infrastructure project: connecting Caye Caulker, a popular Caribbean island, to the national power grid for the first time. Historically, the island relied on expensive and polluting diesel generators. The solution was a 10-mile (approximately 16 km) submarine cable from neighboring Ambergris Caye, complemented by underground distribution networks and a new 7.5 MVA substation on Caye Caulker.

While the submarine portion gained the most attention, the onshore underground cable network and substation control systems were equally critical. This case study examines how Power Cable (15kV/25kV class), MV-105 cable (34.5kV class), and PLTC/ITC cable were deployed in the island's underground and substation environments—solving technical challenges unique to Belize's tropical coastal conditions.

Technical Requirements for the Onshore Cable System

BEL's specification for the Caye Caulker land portion demanded the following parameters:

These parameters reflected the harsh reality of Caye Caulker: sandy, corrosive soil; high groundwater table; direct sunlight; seasonal hurricanes; and confined underground duct banks.

Cable Solutions Deployed

MV-105 Cable – 34.5 kV Underground Feeder

Application:From the submarine cable landing point to the new 7.5 MVA substation (approx. 5 km total).

Why MV-105?

BEL selected MV-105 (34.5 kV class) for its superior electrical and mechanical performance. The cable's cross-linked polyethylene (XLPE) insulation provides:
Continuous 90°C conductor temperature – essential for tropical underground ducts with limited heat dissipation.
Moisture resistance: the XLPE insulation is inherently water-blocking, critical in Caye Caulker's water-saturated sandy soil.
Mechanical robustness: the cable includes a copper tape shield and overall PVC jacket, protecting against excavation damage and rodent attack.

Our MV:105 cable goes beyond the standard. It features enhanced UV-resistant outer jacket (tested to 720 hours accelerated weathering per ASTM G154), FT4 flame test compliance (IEEE 1202), and oil resistance for substation termination areas. Additionally, the cable is fully UL-listed, giving BEL immediate regulatory acceptance.

Power Cable – 15 kV Class Distribution Cable

Application: From the substation secondary side to existing island distribution poles and pad-mounted transformers.

Why Power Cable?

The 15 kV class power cable connects the substation to Caye Caulker's legacy low-voltage network. Key characteristics:
Compact stranded copper conductor– for flexibility during manual pulling in congested underground conduits.
XLPE insulation + PVC jacket – withstands wet locations, direct sunlight, and occasional salt spray.
Neutral/ground wires integrated – simplifies installation in space-limited manholes.

Our 15 kV power cable offers superior flexibility (minimum bending radius 7× OD vs. industry standard 10× OD), reducing installation time and avoiding cable damage in tight 90° bends common on small Caribbean islands. The cable also carries a 30-year performance warranty against insulation degradation when installed per BEL's specifications.

PLTC/ITC Cable – Substation Control & Instrumentation

Application: Inside the new Caye Caulker substation – connecting protection relays, meters, circuit breaker control circuits, SCADA sensors, and auxiliary power.

Why PLTC/ITC?

BEL specified Power-Limited Tray Cable (PLTC) and Instrumentation Tray Cable (ITC) for their:
Shielded pairs – 100% foil shield with drain wire provides excellent EMI/RFI rejection, critical near the 34.5 kV main transformer.
Flame retardance – FT4 vertical tray rating per UL 1685, mandatory for substation cable trays without conduit.
Oil and chemical resistance – the PVC jacket resists hydraulic oil, transformer oil, and cleaning solvents.
Color-coded pairs – simplifies identification and reduces wiring errors.

Our PLTC/ITC cable is UL-listed under UL 13 and UL 2250, meeting both PLTC and ITC requirements in one product. For BEL's tropical environment, we provide a sunlight-resistant jacket (per UL 1581) and flexible stranding (Class K stranding) that withstands repeated bending during maintenance. The cable also includes a sequential footage marking on the jacket, allowing BEL to track exact lengths installed without waste.

Project Challenges and How Our Cables Solved Them

About Us

For BEL and future Caribbean utility clients, our cables offer:

Full UL certification: Immediate regulatory acceptance, no project delays.
Tropical-hardened design: UV-resistant, oil-resistant, and water-blocking as standard, not options.
Superior flexibility: 15 kV power cable with 7× OD bending radius, cuts installation labor by ~20%.
Dual-rated PLTC/ITC: One cable for both power-limited control and instrumentation, reducing inventory.
Traceability: Sequential footage markings eliminate waste and simplify inventory management.

Conclusion

The Caye Caulker submarine power interconnection project represents Belize's most significant grid modernization in a decade. While the submarine cable connects the island, the onshore MV-105, 15 kV Power Cable, and PLTC/ITC cables make the connection reliable, safe, and maintainable.

By supplying UL-certified cables with UV resistance, flame retardance, oil resistance, and flexibility, our company demonstrated that we understand the real-world conditions of Caribbean utility projects—hot, wet, salty, and space-constrained. The successful energization of Caye Caulker in late 2025 validates our cable technology and positions us as a trusted partner for similar island electrification projects across the Caribbean and Central America.

Contact us

Ready to power your next Caribbean or coastal infrastructure project? Contact us today for UL-certified MV-105, Power Cable, and PLTC/ITC solutions engineered to withstand heat, humidity, salt, and tight spaces — because reliable power starts with the right cable.

Tel/WhatsApp/WeChat: +86 135 1078 4550 / +86 136 6257 9592
Email: manager01@greaterwire.com