JQE 27274 092611
1-1
SECTION 1 - INTRODUCTION
1.1
SCOPE OF MANUAL
This manual contains instructions for the installation, operation and maintenance of the specially
modified Kepco JQE 25-20MVPY-27274, “HALF-RACK” Power Supply, manufactured by Kepco,
Inc., Flushing, New York, U.S.A. This model is hereafter referred to as JQE Special Power Supply
or JQE Special. Additional copies of this manual can be downloaded from the Kepco web site at
http://www.kepcopower.com/support/opmanls.htm#jqe.
1.2
GENERAL DESCRIPTION
The Kepco JQE Special Power Supply is a unipolar, linear, precision regulated voltage source in
a half-rack configuration. The power supply has a rectangular voltage-current limit output char-
acteristic. It features full range voltage control, from zero to the nominal output voltage value,
and current limit control, from a small offset of 0.5% of nominal output current to the nominal
output current value. The JQE can be operated as either a voltage source or a current source.
The input source power is an a-c line, single phase, either 115V or 230V a-c (nominal) value.
The nominal a-c input value is established by changing some jumpers on the power trans-
former's terminal block.
The JQE Special power supply has linear, full-dissipation series-regulators (NPN) driven by an
integrated circuit operational amplifier. A sharp current-limit circuit enables current control oper-
ation of the power supply. The output voltage of the JQE power supply can be programmed
remotely. All necessary connections are available on terminals at the rear barrier-strip.
The compact design of the JQE Specials was made possible by a unique heatsink design of
exceptional efficiency in combination with highly reliable low-noise fans. All JQE power supplies
feature all-silicon design with conservatively rated components for added reliability.
1.3
FEATURES.
The JQE Special includes the following features:
a) Two panel meters which permit simultaneous monitoring of the output voltage and out-
put current.
b) Overvoltage Protection. This protection acts simultaneously on the circuit breaker’s volt-
age coil and the electrical “crowbar” that shorts the output through a silicon-controlled
rectifier (SCR) if the output voltage exceeds a preadjustable limit on the sensing lines
(see Table 1-1 for specifications).
c) Zero and full scale voltage calibration for local front panel voltage control.
d) Full scale current calibration for CURRENT LIMIT.
e) Zero and full scale current calibration for VOLTAGE MONITOR
f) Zero and full scale current calibration for CURRENT MONITOR
The main chassis frame of the power supply is constructed from cold-rolled steel, as is the per-
forated wrap-around cover. Front panel material is aluminum (Refer to FIG. 1-3 for finish).
