Overview
Manuals
Operational Safety
Field Maintenance Notice
Breaker Gas Monitoring
Features:
- Calibrated for Sulfur Hexafluoride (SF₆) gas mass
- Features an integrated thermal compensation element
- Built with a 316 stainless steel casing to protect the internal instrumentation against extreme industrial corrosion, humidity, and UV damage
Its core function is to monitor the concentration of insulating gases inside high-voltage switchgear (such as sulfur hexafluoride (SF6) circuit breakers or gas-insulated switchgear (GIS)). Since gases such as SF6 play a crucial role in the insulation and arc-extinguishing processes of substations, this relay can prevent catastrophic arc breakdown faults caused by local gas leaks, thereby providing fundamental and routine protection for the safe operation of the entire power grid.
When the density of the insulating gas inside the equipment decreases due to leakage and falls below a preset safety threshold, the equipment will sequentially trigger the "Level 1 Gas Replenishment Alarm" contact and the "Level 2 Circuit Breaker Forced Trip/Lockout" contact. These electrical signals will be immediately uploaded to the substation's central control system to prevent operations that may generate dangerous electric arcs. At the hardware level, the equipment provides complete dual redundancy or multi-channel protection to ensure that the power grid can promptly perform emergency isolation and live gas replenishment maintenance.
The 1HSB495663-3 1233-4270CNTHB ABB Density monitor relay with rain cover may still be available for purchase and support from Moore Automated Company beyond End-Of-Life (EOL) by the manufacturer (OEM).
ABB 1HSB495663-3 1233-4270CNTHB Density monitor relay with rain cover info(Datasheets), Link
Important Notice: Other accessories, manuals, cables, calibration data, software, etc. are not included with this equipment unless listed in the above stock item description. All prices are shown in USD.
The internal microswitch has been factory-calibrated. When gas leakage reaches a preset pressure threshold, the switch will be triggered, forming a two-stage safety protection network:
Level 1 (Alarm): Issues a warning signal indicating a small SF₆ gas leak, requiring gas replenishment.
Level 2 (Lockout): If the gas density drops below the critical insulation minimum, mechanical locking is triggered to prevent the high-voltage circuit breaker from tripping or exploding due to an unextinguished arc.
This monitor is typically used with a three-way manifold valve block and a rain cover connector. This combination allows technicians to connect field pressure gauges and test internal electrical contacts during planned maintenance downtime without releasing any SF₆ gas into the atmosphere.
Match both ABB part number 1HSB495663-3 and device code 1233-4270CNTHB to the original LTB breaker record. Pressure connection, contact wiring and weather cover must be verified on site.
