The Terasaki XS800hs XS Series is a step up from the XS800ns in terms of both breaking capacity and design. The key differentiator is in the model suffix: "hs".
Here is a detailed overview of the Terasaki XS800hs.
Key Differentiator: "hs" vs. "ns"
• h: Stands for High Breaking Capacity. This breaker is built with a more robust interrupter and mechanism to safely handle much higher levels of fault current compared to the standard "n" version.
• s: Stands for Withdrawable or Slide-out version. This is a critical feature for maintenance and safety.
Key Features and Highlights
1. Withdrawable Design (The "s" in hs):
◦ This is the most significant operational feature. The entire breaker is mounted on a chassis that allows it to be racked in and out of the fixed mounting frame.
◦ It has distinct, interlocked positions:
■ CONNECTED: The breaker is fully engaged, and power can flow.
■ TEST: The main power contacts are disconnected, but the control wiring is still connected. This allows for safe testing of the trip functions and control circuits without energizing the main busbar.
■ DISCONNECTED: The breaker is fully isolated from both the main busbars and the load terminals.
◦ Advantage: Enables easy maintenance, testing, and replacement without the need to shut down the entire main switchboard, drastically reducing downtime.
2. High Breaking Capacity (The "h" in hs):
◦ The XS800hs is engineered to interrupt extremely high short-circuit currents. Its Ultimate Breaking Capacity (Icu) is significantly higher than that of the XS800ns model.
◦ While exact values depend on voltage, it's common for the "h" version to have an Icu of 100kA, 150kA, or even higher at 415V. This makes it suitable for applications close to large transformers or in systems with high available fault current.
3. Advanced S-Type Trip Unit:
◦ Like the XS800ns, the "hs" model is equipped with the intelligent S-Type Electronic Trip Relay (ETR).
◦ It provides fully adjustable protection functions:
■ Long-Time Delay (L): Overload protection.
■ Short-Time Delay (S): Selective short-circuit protection.
■ Instantaneous (I): High-level fault protection.
■ Ground-Fault (G): Sensitive earth leakage protection.
◦ This allows for precise coordination with other protective devices in the network.
4. Enhanced Safety and Interlocks:
◦ The withdrawable mechanism is equipped with safety interlocks to prevent incorrect operation, such as:
■ The breaker must be in the "OFF" position to be racked between positions.
■ The compartment door cannot be opened when the breaker is in the "CONNECTED" position.
■ It prevents insertion/withdrawal under load.
5. Communication and Metering:
◦ The S-type trip unit is typically ready for an optional communication module (e.g., TML-CM, Modbus, Profibus).
◦ This enables remote monitoring (current, voltage, power, energy), control, and extensive data logging of power system parameters and trip events.
Technical Specifications (Typical)
Feature
Specification
Frame Size
800A
Rated Current (Iu)
Adjustable via S-type ETR, e.g., 400A to 800A.
Rated Operational Voltage (Ue)
690V AC
Breaking Capacity (Icu)
High - e.g., 100kA, 150kA at 415V (Always verify with the specific manufacturer's datasheet).
Trip Unit
Electronic (S-Type)
Type
Withdrawable
Standard
IEC 60947-2
Common Applications
The XS800hs is used in the most critical and demanding parts of a power distribution system:
• Main Incomer: In large industrial plants, commercial high-rises, and data centers where the available fault current from the utility supply is very high.
• Large Power Generation: In switchboards for generators and prime power sources.
• Marine & Offshore (Specialty): As main switchboard breakers on ships, rigs, and FPSOs, where system reliability, high fault capacity, and easy maintenance are paramount. The withdrawable feature is crucial here.
• Infrastructure Projects: In critical power distribution for airports, railways, and hospitals, where system selectivity and the ability to perform maintenance without a total blackout are essential.