Standby (Sb) Option; Sb Option Operation; Transfer Switching Speed - Xantrex7 UX - REV A Owner's Manual

Inverter/charger

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4.0 Operation

Standby (SB) Option

Units equipped with the standby (SB) option have an additional LED and circuit

breaker on the front panel.

See Figure 4-2 on page 53 for the location of the Standby Charger Status LED

and SB Charger AC Input Breaker.

The standby option adds an internal battery charger and automatic transfer relay.

This allows the unit to operate as either a battery charger or inverter (but not

both at the same time). An external source of AC power (e.g., utility or generator)

must be supplied to the inverter's AC input in order to allow it to operate as a

battery charger. When the unit is operating as a charger, it's AC output is

The inverter automatically becomes a battery charger whenever AC power is

delivered to its AC inputs. There is a 15 second time delay from the time the

inverter senses that AC is present at its input and when the transfer is made. This

delay is built in to provide time for a generator to spin-up to a stable voltage and

avoid relay chattering. While in the battery charger mode, the inverter's AC input

is internally connected to the inverter's AC output.

For 120 Vac units, 30 amps is the maximum power that can be handled by the

inverter's internal wiring and transfer relay. For 230 Vac units, 15 amps is the

maximum power that can be handled by the inverter's internal wiring and

transfer relay. This amperage can be passed directly from the AC input to the AC

output. During heavy charging, part of this input amperage will be consumed by

the charger.

While this inverter is not designed specifically as a uninterruptable power supply

(UPS) system, its transfer time is normally fast enough to support computers.

The transfer time is approximately 35 milliseconds when switching from charger

to inverter mode.

When switching from inverter to charger, the inverter waits approximately

15 seconds to ensure the AC source is stable (generator up to speed) and then

makes the transfer in approximately 30 milliseconds.

Success as a UPS will vary with computer models and cannot be guaranteed.

P/N 975-0026-01-01 Rev A 06/2002

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Ux series