OnLine Power PBC I - Manual (Page 16)

1–11 Theory of Operation
Functional Block Diagram shows the power path through the PBC, See Illustration 1- 6.
For domestic models and theory of operation 1-11A Illustration 1-6A for international models.
Input Stage
•
The utility company’s power sinewave enters the system by way of TB 1.
•
The ACT’s, TVSS , supply input surge protection before CB-1A & CB-1B for domestic models.
•
The CB-1A and CB-1B linked for common trip, CB-1A on 120V is rated for the higher current and CB-1B
on 240V rated for the lower current on the domestic models.
•
From the circuit Breakers to the 2 stages of EMI filters, network where attenuation of any power line noise
occurs.
•
On exiting the input filter, the AC voltage enters the Autotransformer and is stepped down to 120 VAC
required by A1 PCBA UPS Inverter Module.
The Power Splits Into Two ( 2 ) Directions
•
Quick Battery Charger, A 7 PCBA, reduces the recharge time after the batteries after a power outage.
•
The Power Conditioning UPS Module, A 1 PCBA.
Power Conditioning Stage
• The Power Conditioning Module has 6 sections and their functions are follows:
•
The power from the on board Battery Charger supplies a float charge to the Standby Reserve Battery
System.
•
The Emergency Bypass line connects the input to output by way of on board Emergency
Bypass Switch.
•
The Power Rectifier section provides DC Voltage to the DC Chopper.
•
The ± DC Choppers change DC Voltage from the power Rectifier and the batteries to a pulse Voltage for
the DC/AC Inverter.
•
The DC/AC Inverter supplies a Pulse Width Modulation Output through the Bypass Switch to the Output
Filter.
•
The Output Filter changes the Pulse Width Modulation to a clean sinewave and to the Output Isolation
Transformer.
Power Output Stage
• The Output Filter connects to the 2 Fans, B 2 and B 3, providing constant airflow to cool the Electronic
Tray components, and to T 2, Output Isolation Transformer.
• The Output Isolation Transformer, T2, connects to CB-3 A and CB-3B, the Output Circuit Breaker and
provides voltage to the terminals of TB-2 and the load.
Power Outage Stage
If there is a power outage; the Standby Reserve Battery System supplies the power through CB-2
to the UPS. The Battery DC voltage enters the ± DC Chopper, DC / AC Inverter, Bypass Switch
and to the Output Filter, Output Transformer, CB 3, to TB 2, and the load.
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