Eaton Electrical SC200 manual Installing the External Batteries if applicable, Battery Sizing

Installing the External Batteries (if applicable)

Installing the External Batteries (if applicable)

This section applies to APS3-059, APS3-061 and APS6-059 power systems only.

One 48 V battery string can be connected to APS3-059 and APS3-061 and up to three 48 V battery strings to APS6-059 power systems.

A 48 V battery string consists of either:

•24 Valve Regulated Lead Acid (VRLA) 2 V cells or

•Four VRLA 12 V monoblocs

Because of the wide range of battery types and sizes available, we do not supply batteries with the above mentioned power systems and therefore do not cover battery installation in this guide. Always install batteries according to the relevant battery manufacturer’s instructions.

Battery Sizing

Battery manufacturers provide various types of information for sizing batteries such as constant current discharge and constant power discharge data. Your battery supplier will be able to assist you with sizing the battery for your application.

Before a battery can be sized, the following information is required.

•Required backup time

•Minimum cell voltage (typically 1.83 V per Cell)

•Load profile

•Operating temperature

In telecommunications and data applications most loads are constant power for a specified backup time. Therefore, for sizing a battery for the required backup time, constant power discharge data should be used.

For charging the battery, constant current discharge data should be used. When charging the battery, battery current limit should be used to set the battery charge to no more than the maximum recharge specified by the battery manufacturer.

Batteries for use in North America must be a UL recognized type, category BAZR2.

Battery Location

Valve Regulated Lead Acid (VRLA) batteries emit very small amounts of hydrogen gas into the surrounding atmosphere under normal float charging conditions. For that reason batteries should never be installed in a sealed enclosure or cabinet.

Install the batteries in a well-ventilated location to prevent accumulation of hydrogen gas to flammable or explosive levels.

Building air conditioning and ventilation systems already in place for optimum equipment operation and comfort of personnel usually meet or exceed VRLA battery ventilation requirements. For specific battery ventilation requirements, always refer to the battery manufacturer’s installation instructions.

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IPN 997-00012-41D December 2006