Alpha Technologies APP 60S - Manual (Page 7)

016-001-B0-002 6/97 016-001-B0-002 6/97 016-001-B0-002 6/97 016-001-B0-002 6/97 016-001-B0-002 6/97
The APP60S Service Power Supply is a portable device used to provide temporary power for
Alpha AP Series standby power supplies and XP Series uninterruptible power supplies while
they are being serviced. The APP60S can be used in either pole or ground-mount enclosures
to provide signal processing equipment in Cable Television and Broadband LAN distribution
systems with current-limited, regulated AC power.
The APP60S Service Power Supply contains a front panel ammeter to measure the output
current to the load; an output fuse to protect against excessive short circuit currents; a
"LINE" indicator to verify AC input power from the utility; an input fuse to provide additional
voltage protection; and a 30/60 VAC switch for output voltage selection (48/60 for 50 Hz
units).
UL Listed and CSA Approved, the APP60S Service Power Supply is designed to be rugged,
reliable and versatile. Alpha Technologies, recognized as an international market leader in
the field of backup power, offers complete technical support and prompt, reliable service
to ensure that your power supply continues to provide years of trouble-free operation.
1.2 Theory of Operation
The APP60S Service Power Supply contains a ferroresonant transformer and a resonant
capacitor. During AC LINE operation, utility power is fed into the primary winding of the
ferroresonant transformer, T1. An AC capacitor, C1, forms the resonant circuit of the
ferroresonant transformer which provides excellent noise and spike attenuation, short
circuit current limiting, and output voltage regulation. Note: The ferroresonant transformer
produces a "quasi" square wave output which resembles a rounded square wave.
During LINE operation, AC power enters the APP60S where it is regulated (at the required
output voltage) and passed onto the load via the SPI (Service Power Inserter) located inside
the power supply enclosure. A switch, located on the SPI, toggles output power from the
power supply requiring service to the APP60S.
IMPORTANT NOTE: WHEN MEASURING THE OUTPUT VOLTAGE OF
FERRORESONANT TRANSFORMERS, USE ONLY A
TRUE RMS AC VOLTMETER. NON-RMS READING
METERS ARE CALIBRATED TO RESPOND TO PURE
SINE WAVES AND WILL NOT PROVIDE AN ACCU
RATE READING WHEN MEASURING A "QUASI"
SQUARE WAVE OUTPUT.
1
1. INTRODUCTION
1.1 THE APP60S SERVICE POWER SUPPLY