Occasionally there are sites where the CPPIN-3T Manual Call Point (MCP) can be activated by high levels of Radio Frequency Interference (RFI). 

This activation may be caused by the close proximity of electric arc welding equipment or other equipment generating high power level RF signals. This activation can occur despite the conventional MCP having almost three times the RF immunity level required by NZS 4512:2021.

Although the immunity response has been further improved with the latest v8.20 PCB upgrade, the MCP may still be subject to nuisance activation if a large enough transient signal is transmitted. 

For affected sites Pertronic recommends fitting 10nF monolithic capacitors across the Circuit In and Circuit Out connectors of affected CPPIN-3T MCP’s.”

The photo above shows the installed capacitor.

A suitable capacitor, available from Jaycar is the 10nF 50Vdc MonolithicCapacitor:  Cat No: RC5480

Capacitors are available from other suppliers. However please ensure the capacitor selected is non-polarised. In very high RF environments it may be necessary to fit higher value capacitors. In these cases, please contact Pertronic Tech Services for site specific advice.

Resolution of this frustrating nuisance alarm problem demonstrates the value of having an in-house, NZ based, Pertronic Industries’ R&D team.

Posted in Technical, General, Pertronic, research and development; Tagged Weatherproof Manual Call Points, Manual Call Points;