Jul 31, 2025
Understanding RHZ1 OL: Key Specifications That Set It Apart from RHZ1 2OL
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How RHZ1-OL and RHZ1-2OL Are Built
Differences in Cable Layers
The big difference between RHZ1-OL and RHZ1-2OL is their layers. RHZ1-OL has one water-blocking layer (that’s what “OL” means). RHZ1-2OL has two. This makes the 2OL version better at keeping water out. It’s great for wet places or areas that might flood.
The conductors of the two types of cables can be Class 2 aluminum or copper, with aluminum conductors being more commonly used. These are compact and conduct electricity well. RHZ1-2OL has better water resistance than RHZ1-OL,providing better protection for conductors and insulation layers from moisture damage.
Insulation and Outer Sheath
Both cables use cross-linked polyethylene (XLPE) for insulation. TR-XLPE can also be used in this type of cable. It’s great for handling heat and electricity. The insulation has a semi-conductive layer and a copper wire screen. A PO sheath adds protection.
The outer PO sheath resists UV and wear. This is true for both RHZ1-OL and RHZ1-2OL. Depending on the usage environment, it can also have oil resistance to cope with harsh chemical or physical conditions.
How RHZ1-OL and RHZ1-2OL Perform Electrically
Voltage and Current Capacity
Both cables work for medium voltage systems, from 6/10kV to 18/30kV. They meet global standards like IEC 60502-2 for cables rated from 1kV (Um=1.2kV) to 30kV (Um=36kV). How much current they carry depends on the conductor size, how they’re installed, the temperature. The number of water-blocking layers doesn’t change this.
Electrical Properties
XLPE insulation keeps electrical losses low in both cables. They have high insulation resistance. The extra layer in RHZ1-2OL doesn’t affect its electrical performance much. But it helps the cable last longer in wet conditions by stopping water-related electrical issues.
Performance Under Overload
Both cables stay reliable under high heat or sudden voltage spikes. XLPE handles heat well. The double-layer design of RHZ1-2OL makes it stronger during long periods of electrical or environmental stress, like in wet underground setups.
How RHZ1-OL and RHZ1-2OL Handle Heat
Operating Temperatures
Both cables can run at conductor temperatures up to 90°C. They can handle short-circuit temperatures up to 250°C. These limits follow IEC standards for medium voltage cables.
Current carrying capacity
How well the cables current carrying capacity depends on the conductor shape and installation. So, Products with the same voltage and conductor, their heat release is almost the same in normal conditions.
Resistance to Heat Aging
XLPE insulation makes both cables resist heat-related wear over time. Their structure keeps them durable. In very wet underground setups, RHZ1-2OL’s extra water-blocking layer helps protect the insulation from moisture damage.
Where to Use RHZ1-OL vs. RHZ1-2OL
Industrial and Power Networks
RHZ1 cables are perfect for underground setups where fire safety and water resistance are key. They work well indoors, in tunnels, trenches, shafts, or buried directly. Both cables are good choices. But RHZ1-2OL’s better water protection makes it ideal for deep burial or flood-prone spots.
Use in High-Risk or Critical Areas
In places like chemical plants or tunnels, where fire spread and toxic gases are concerns, both cables works well. They’re low smoke and halogen-free (LSZH). For critical setups like nuclear plants or high-speed rail, RHZ1-2OL’s double-layer design offers extra reliability.
Residential and Commercial Uses
Medium voltage cables aren’t common in homes. But large commercial buildings with their own substations can use them. Either cable works, depending on the setup and risks. They’re widely used in transformer stations, power plants, and factories.
Picking between RHZ1-OL and RHZ1-2OL depends on the environment, not electrical performance. RHZ1-OL is cost-effective for city networks with some moisture. RHZ1-2OL is better for wet conditions.
For reliable, standards-compliant cables (like IEC 60502-2), contact TDDL for RHZ1-OL options. These cables handle mechanical stress and pulling forces. They stay durable in tough setups.
FAQ
Q: What situation are RHZ1-OL and RHZ1-2OL cables usually used for?
A: Both cables carry medium voltage power. You'll find them in power networks, factories, and business substations. RHZ1-OL works well for regular underground setups where it's damp but not soaked. RHZ1-2OL is better for tough spots, like near the sea or rainy areas. It has stronger protection against water.
Q: Can I bury RHZ1-OL and RHZ1-2OL cables straight in the ground?
A: Yes, both types are made for direct burial. Pick RHZ1-2OL for wetter places. Think high water tables or flood zones. Its two water-blocking layers give extra defense against water getting in.
Q: Is RHZ1-OL or RHZ1-2OL safe for fire-risk areas?
A: Yes. Both are low smoke zero halogen (LSZH) cables. This makes them safe for risky spots like tunnels or public buildings. If a fire breaks out, they make very little smoke. They also don't release poisonous halogen gases.
