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Parallel / Dual Connections

TEC offers a variety of services for your power supply systems and our network of field service engineers are dedicated to giving you the perfect system to suit your needs.

Levitating Objects
Wind Mills

Parallel System Connections


  • A UPS with parallel capacity can be installed with either a single or a dual input supply, but the overall rating must be adequate enough to supply the parallel UPS irrespective of operation.

  • The AC supply must be rated to the maximum input current of each UPS module and multiplied by the number of UPS modules within the system

  • Integral to a parallel redundant UPS configuration, the supply rating can be the same as that used for a parallel capacity system or equal to the total current required by each of the individual UPS modules (a 10% allowance is made for charging purposes and system losses)

  • Cables in a parallel UPS system should be sized in accordance with the rating of each UPS module to which they are connected (input cables) and rated to the supply or maximum output power available from each UPS module (output cables). The same length for both Input and output cables to try to ensure an even power distribution



Dual Input Connections


The UPS resilience is further increased through the practice of using dual

AC power sources, rather than single;

  • This gives protection against a single point of failure, and it allows the rectifier and bypass to be supplied from different sources, even possibly different sub mains

  • Transformer based UPS are supplied with dual input terminals as standard

  • A transformerless UPS is slightly different as the Rectifier and Bypass supplies require a common neutral –These can still be installed in a dual input, but supplied from the same source (factory fitted option only)

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