American Power Conversion VS 50 - Manual (Page 25)

Magnum VS –48 Vdc User Manual Page 25
4 Technical Description
The Power System is designed to supply safe –54 Vdc primary power through the use of up to 10 rectifier modules.
The controller will monitor all functions and provides battery management including controlled battery recharge with
temperature compensation and low voltage disconnect. Integrated dc output distribution supports loads ranging
from ¼ A all the way to 60 A. The controller can monitor up to 4 discrete external events with voltage free (“dry
contact”) user inputs.
4.1. Rectifier Management
AC Input Power
The basic component of the power system is the rectifier module, which rectifies utility ac into nominal 48 Vdc.
Each rectifier module requires 85 – 264 Vac, 47 – 63 Hz single phase power. Available cord sets include a variety
of blade and twist lock plugs. Dedicated wiring inside conduit can also be used.
DC Output Power
The dc outputs of all the rectifiers in the system are connected to a common bus that is rated to carry the current of
the entire system. The rectifier modules will equally share the entire load, independent of the controller. The
rectifiers will continue to provide dc power (-54.5 Vdc) if the controller is removed or fails.
Rectifier alarms reporting
The rectifier has numerous sensors inside the unit that monitor fan fail, high temperature, high/low voltage, etc.
These rectifier sensors trigger outputs that are monitored by the controller. In addition rectifier current is measured
inside each rectifier. The controller can trigger output relays in the event of a rectifier alarm. Refer to Section 4.5
for controller functions.
4.2. System Management
System Voltage Monitor and Control
The controller monitors and adjusts the system voltage. It uses a voltage trim input to the rectifier to precisely
control the dc output voltage. In the event of controller removal or failure, individual rectifiers will default to the
analog voltage level (-54.5 Vdc) preset at the factory. System high and low voltage alarms are reported by the
controller.