ABB SACE SH800 800A 660V Switch Disconnector
The ABB SACE SH800 is a robust switch disconnector rated for 800A continuous current at 660V AC. Part of the ABB SACE SH series, this device provides reliable isolation and load switching for industrial power distribution systems, PLC control cabinets, motor control centers, and main switchboards. Its compact design and high breaking capacity ensure safe maintenance and emergency disconnection.
Electrical Specifications
Rated Thermal Current (Ith): 800A
Rated Operational Voltage (Ue): 660V AC 50/60Hz
Rated Insulation Voltage (Ui): 1000V
Rated Short-time Withstand Current (Icw): 20 kA for 1 second
Rated Making/Breaking Capacity: 10 x Ie (AC-23A category)
Utilization Category: AC-23A (switching of mixed loads including motors)
Pollution Degree: 3
Mechanical Construction
The SH800 features a double-break moving contact system made of silver-alloy material, ensuring low contact resistance and high resistance to welding. The housing is constructed from glass-fiber reinforced polyamide (PA66) with self-extinguishing properties (UL94 V-0). Terminals accept copper or aluminium cables up to 2x 240 mm² or single 400 mm². The switch is available with front or side rotary handle operation, and padlockable in the OFF position (up to 3 padlocks).
PLC Integration and Auxiliary Contacts
For PLC-based monitoring and control, the SACE SH800 can be fitted with up to 4 auxiliary contact blocks (normally open and normally closed). These contacts are rated 10A at 250V AC and can directly interface with 24V DC PLC digital inputs. An optional undervoltage release (220-240V AC) and shunt trip release (same voltage) enable remote tripping from a PLC output, facilitating emergency stop or load shedding sequences. The switch position status (ON/OFF) can be reliably transmitted to a PLC for interlocking and sequence logic.
Operating Mechanism
The switch employs a quick-make, quick-break mechanism independent of handle speed. This ensures consistent arc extinction and prevents contact welding. The stored energy mechanism provides a positive indication of contact position, with visible weld-breaking capability. Operating torque required is approximately 15 Nm for the 800A frame, compatible with standard cabinet door interlocking systems.
Environmental and Safety Compliance
Ambient operating temperature ranges from -25°C to +70°C with no derating up to 50°C. Storage temperature is -50°C to +85°C. The device is IP20 protected on terminals (IP40 on front when mounted). It meets IEC 60947-1, IEC 60947-3, and EN 60947-3 standards. CE marked and certified by CCC, EAC, and UL (pending file). The switch disconnector provides visible contact gap (≥ 8mm) for safe isolation as required by EN 60204-1 for machinery safety.
Applications in PLC Panels
In PLC-controlled systems, the SH800 is commonly used as a main incoming switch for distribution boards supplying PLC power supplies, servo drives, and I/O modules. It also serves as a manual motor disconnect for large pumps, fans, and compressors. The auxiliary contacts allow a PLC to detect unauthorized switch operation or interlock with door position sensors. For high-availability systems, two SH800 switches can be mechanically interlocked (with a kit) for main-standby or generator-mains transfer.
Installation and Maintenance
Mounting is via four M6 screws on a 160mm × 200mm footprint. Torque terminals to 35 Nm for copper cables. Periodic maintenance every 5000 operations or annually includes contact resistance check (should be < 200 µΩ per pole) and visual inspection of arc chambers. The switch is rated for 10,000 mechanical operations and 5,000 electrical operations at full load.
Conclusion
The ABB SACE SH800 800A 660V switch disconnector provides reliable, safe isolation and load switching for industrial power systems. Its robust construction, high breaking capacity, and PLC-friendly auxiliary contacts make it an essential component in modern control cabinets and power distribution units.
