Schaller VISATRON VN115/87 Crankcase Oil Mist Detector

Product Description

The VN115/87 is a well‑known oil mist detector manufactured by Schaller Automation under the VISATRON brand. It adopts a header‑pipe gas sampling structure and infrared opacity measurement principle, designed for four‑stroke trunk piston diesel engines. It continuously extracts mixed gas samples from each crankcase chamber and measures oil mist concentration. The cast metal housing is vibration‑resistant and complies with marine classification society standards. The original VN115/87 EMC has been phased out and upgraded to VN115/87plus. Most available units on the market are refurbished or surplus spare parts for marine and industrial engine safety systems.

Product Functions

• Real‑time continuous sampling and monitoring of oil mist opacity inside the diesel engine crankcase
• Four‑level adjustable alarm threshold from 0.5% to 25% opacity to trigger relay alarm output when oil mist exceeds limits
• Built‑in heating and filter components to reduce condensate and dust interference on the optical measuring head
• Local visual status indication and dry contact alarm signal output for engine safety interlock and shutdown
• System self‑diagnosis for sampling pipeline blockage, measuring head contamination and internal power faults
• Provide early warning of bearing overheating, cylinder liner friction and crankcase explosion risks

Application Scenarios

• Oil mist safety monitoring for medium‑speed and high‑speed four‑stroke marine diesel engines on cargo ships and ferries
• Crankcase explosion protection for land‑based stationary diesel generator sets in power plants
• Offshore platform and mining diesel engine safety supervision systems
• Retrofit and spare replacement for old VISATRON VN/87 EMC series monitoring equipment
• Engine room safety compliance projects required by IACS marine specifications
• Emergency protection for large industrial reciprocating internal combustion engines

Common Problems

• False high oil‑mist alarm：dust or condensate contaminates the infrared optical window, pipeline water accumulation or filter clogging
• No alarm response during actual oil mist generation：measuring head aging, optical lens fouling or sampling pipe blockage
• Sampling pressure abnormal：leaking header pipes, loose pipe joints or blocked scavenging air filter
• Intermittent random fault alarms：heating element failure, unstable power supply and internal wiring oxidation
• Alarm relay cannot output normally：relay contact burnout, terminal corrosion and poor wiring contact
• Measuring value drifts gradually：long‑term soot deposition on optical components and aging of infrared sensor
• Difficult spare‑part sourcing：original EMC version discontinued, only refurbished assemblies and aftermarket maintenance kits available