27
3.0 Operation
©2002 Xantrex Technology Inc. All Rights Reserved.
P/N 975-0049-01-01 Rev A 10/2002
Figure 3-2
3-Stage Battery Charger Graph
Inverter to Charger Transition
The Trace UR-UPS constantly charges the batteries as
long as power is being supplied to the unit (from either
the utility grid or a generator).
When a utility outage occurs, the unit switches to the
batteries to maintain power to the connected load. This
is accomplished by an automatic transfer relay, rated at
15 amps and protected by a 15 amp circuit breaker.
When the AC utility (or generator) power returns, there is
a built-in 20 second delay before the unit switches from
inverter to charger mode. This delay allows the utility
power to stabilize after an outage, or for the generator to
achieve a stable voltage, thus protecting the connected
load.
Absorption Stage
Bulk Stage
Float Voltage
Charging
Started
Max Charge
Amps
Constant Voltage
Constant Current
Reduced Current and Voltage
DC Voltage
DC Current
Bulk Voltage
80–90% Capacity
100% Capacity
One-Hour Absorption
Period
Float Stage
Battery Charger Operation (continued)