DC Batteries and DC Plant

The Power Feeding Equipment (PFE) and Submarine Line Terminating Equipment (SLTE) are powered from a -48V DC system that has 1+1 redundancy.  Each rectifier is made up of 17 x RT8 48V 60A rectifier modules so the total device capacity is 1020A.  Having such a modular device allows for easy maintenance and expansion if we require more DC.

As we have explained in earlier entries, the PFE is set up such that the system is double end fed (DEF) between the PFEs in Sydney and Guam.  To provide even further redundancy, the PFE at each site is able to single end feed (SEF) the entire system, which equates to approximately 8,500V at 0.95A.  In order to allow for continuous service we have diesel generators which back up the commercial mains and two banks of batteries that can provide a total of 800A DC @ -48V for up to 4 hours in the event of a major catastrophe on the power system in Sydney.  The batteries (pictured ) are HZ-B2 2000 from Haze.  They are sealed lead acid AGM type.

2 thoughts on “DC Batteries and DC Plant

  1. Was an alternative fuel to diesel considered for the generators? I ran across a comment in a business continuity document that a site had selected kerosene rather than diesel because, in case of a regional disaster, hospitals have priority on diesel, regardless of what a site may have contracted for in terms of priority for fuel.

    • Hi Richard, in the original design phase we did consider what other sources of fuel could be used. We looked into gas as a possible source but were worried about disruption to supplies if pipelines broke etc. We really wanted to be self sufficient ( at least for a time). The issue ( and maybe you know more than me) with low flash point fuel like kerosene as compared to diesel (61 deg FP) are the EA regulations on storage of quantities of the order of 20-30,000 litres. To be honest we din’t ask the question about storing kerosene but I imagine it is another kettle of fish to diesel which is well understood and easily permitted. Sorry if we dissapoint here…