Specifications

U-ENS00011_99AtypSMSSpec_Rev2.doc

U-ENS00011 Rev2 12/9/08

Converter input contactor, and the input current limit control shall pro vide converter

protection against excessive input overload conditions.

E. S tep Load Change Operation (0-100%)

In the occurrence of a 100% step load change, the UPS Module inverter shall dra w

power only fro m the converter to provide the required load demand. The system

batteries will not be cycled at any time during a step load change.

F. Input Current Limit

The Converter logic shall provide input current limiting by limiting the AC input current.

Three (3) line-side current transformers shall be employed as a means of sensing the

current amplitude. The DC output current limit values are as follows:

a. Input current limit setting: 110% of nominal rated current.

b. The AC input current limit shall be set up so that the converter can provide sufficient

capacity to the inverter at rated load and have the capability to recharge a

discharged battery.

c. The input current limit protects converter components fro m damage due to

excessive input current.

G. Input Power Demand

The Converter logic and control shall also be capable of pro viding auxiliary current

limiting when initiated by an external dry contact closure (e.g. in the event power

demand is required when the UPS is fed from a gen erator).

Power De mand: Adjustable, maximum 110% of nominal rated current.

2.2.1.2 Charger/Booster

A. General

The charger/booster utilizes solid state Pulse Width Modulation (PWM) controlled

Insulated Gate Bipolar Transistors (IGBT).

B. Battery Charge Current Limit

The converter logic and control circuit DC battery current limiting function enables

controlled battery charging. The battery charge current limit will control the recharge

current by reducing the converter output when the set limit is reached. The following

battery current limit shall be provided as a minimum:

1. Battery charge current limit: 10% of battery Ah rate.

2. Maximum charge current: 20% ampere of UPS rated kVA.

C. Equalize Charge Timer

UPS Module logic and control shall pro vide an electronic equalize charge timer function

(0 to 100hour selectable - default twenty-four (24) hour). Once activated the timer circuit

shall provide a high rate equalizing charge voltage to the system battery for the selected

time. The function can be manually activated and de-activated via the UPS Module LCD.

The level of equalizing voltage shall be equal to that stated by the battery manufacturer