+ Home > PRODUCTS > Weighing indicator > HB-SP12

HB-SP12

Protects load cell and electronic weighing equipment against surges and transients on system cabling

The HB-SP12A/D surge protection device protects load cell and weighing system installations from possible malfunctions or damage to individual strain-gauge bridges of associated elctronic instrumentation etc. caused by severe vervoltages or impulse curents on signal cabling.

Weighbridges, silos and other product batching plant, weighing facilities are typically large metal structures, and are very exposed to direct lightning strikes. Protecting the structure from lightning is not in itself sufficient to prevent the secondary damage to associated electronic systems. Inside individual load cells, strain-gauge bridge insulation may break down under the abrupt shift in local structural voltage as lightning currents are dissipated to local ground, allowing surge currents to flow through the connecting cable into the various indicators and power supplies situated some distance away. The connecting cabling can be armoured, shielded and underground it will make little difference to the transient voltage across the system.

Potentially destructive surges can also be generated from a variety of other sources, including power cable faults, heavy electrical load switching, and other electrical malfunctions, while most factory and plant environments also create significant electrical noise from normal operations such as arc-welding and heavy machinery.

The HB-SP12 protect the system at the point of installation only, so a full system is likely to have at least one SP12 device installed at the weighbridge to protect the load cell(s), and another SP12 in the weighing control cabin to protect the electronics installed there. Additional protection should also be provided for any other systems interconnected with the weighing package eg. remote computer links, data-communications via telephone lines, etc.

Standard Features:

• Protects load cell, weighbridges, process weighing, and silos
• Reliable protection through high surge absorption capacity
• No affect on system accuracy
• Easy field installation in rugged weatherproof enclosure
• Repeated auto-resetting operation without maintenance
• Can be used in intrinsically safe circuits without further certification

Technical Specification:

Physical Dimensions Outline: