Guards monitor and protect DC systems

A new device from Megacon, the international group of electronic products companies whose main manufacturing unit is in Falmouth UK, gives vessel operators and their engineers the ability to monitor and protect against insulation breakdown on DC battery systems up to 800V. The Megacon High Voltage DC Insulation Guard expands the company’s range of AC and DC Guards whilst introducing digital circuitry to provide a faster and more accurate protection device. The Guard trips out alarms if there is a short, giving an immediate warning to crew who then have time to take remedial action.

Regarding the supply of electricity and the reliance of standby power systems such as gensets, the system insulation integrity could not be more important. Regular insulation checking is essential for standby equipment to ensure it is functional when required. The Megacon DC Insulation Guards are permanently on as long as the auxiliary voltage is live, giving 24/7 protection and early warning of developing faults before they can cause a system failure.

The KPM169E & F offer a local indication of the insulation level at all times for the battery backup circuit of the UPS installation. They are capable of handling installation up to 800V DC capacity, via a RG200X adaptor. The KPM169F has an analogue output signal that can be fed into a building management system to give centralised indication of the UPS circuit insulation level. The clear analogue scale is ranged from 0-100k for systems up to 60 V and from 10kto 5M for higher system voltage. In the event that the system voltage drops more than 20% below the system value, the KPM169E/F will trip for an ‘Under Voltage’ condition and the negative rail Fault LED will glow red.

The Guards all come with three relays. This allows the user flexibility in the installation. The three relays are configured as R1 Warning, R2 Alarm, and R3 is Polarity indication. The polarity of the fault is indicated by a blue LED being lit for a negative rail fault or none for a positive rail fault.

The Guards are available as DIN96 panel mounted pointer type instruments, clearly indicating the system status and health. All units are available with a fast response, isolated analogue output. All the Megacon Guards use the latest digital designs to allow for accurate, rapid and reliable warning of an impending system failure, (total processing time down to 50mS).