Standby Power Systems (SPS)
In the simplest DC standby power system, the battery is permanently floated across the system or load in parallel with a rectifier charger. The float charge rating must therefore be capable of supplying the sum of:
- •The float charge rate of the battery.
- •The continuous (standing) load of the system.
In practice, the chargers for CEGB power stations have to fulfil further duties to provide continuity of supply, and the systems described in Chapter 1 have been developed to ensure this.
Summarising these duties, the float charge rating must be selected from the sums of one of the following two systems.
Interconnected unit system
- •The float charge rate of the batteries of two unit systems.
- •The standing load of two unit systems.
- •One half of the station system standing load.
Interconnected station system
- •The float charge rate of two associated batteries.
- •The standing load of the whole of the station system.
In addition to the above requirements, chargers must be designed to operate satisfactorily in parallel, to ensure changeover on-load before a charger is taken out of service.
These are most commonly used to protect POS equipment and single work stations. Standby UPSs allow IT equipment to run off utility power until the UPS detects a problem, at which point it switches to battery power.
At Tekmart Africa, we stock these units. Contact sales for your SPS requirements and one of our solution consultants will gladly assist.