Electrical Test Instruments PI-2500 & PI-5000
Section II - Detailed Description
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Copyright(C) 1994-2008 Electrical Test Instruments, LLC. All Rights Reserved
Page II-4
The output of the test set is controlled by means of a proven SCR controller,
which drives modular solid-state relays. This provides precise initial phase angle
control to reduce DC offset for inductive loads and more consistent pulse cur-
rents. Snubbers are incorporated to eliminate false firing and latching problems.
The phase angle is internally adjustable and is preset for optimal waveforms
with most breakers.
The measurement of output current and time is accomplished by means of the
proven MAC-20, which uses highly accurate A/D circuitry and intelligent firm-
ware to resolve true-RMS values of distorted waveforms. It also provides features
such as preset ON times for convenient jogging of output current without over-
heating the breaker or causing unwanted trips.
The entire test set has been designed for reliability, ruggedness, and ease of use.
Sophisticated electronics in the indicator/control panel and the MAC-20 provide
state of the art accuracy and convenience, while simple connections allow for
easy removal and replacement for transportation or service. All covers are re-
movable, allowing easy access to all internal components. An internal relay
panel located just under the top panel contains most of the circuitry, facilitating
service and maintenance. The rear panel may be removed for access to input
fuses, control fuses, and the SCR board. A large bottom-mounted fan provides
airflow to the transformer and output bus. The cabinet is designed with no pro-
truding components on the sides, so it can be navigated through narrow door-
ways without problems. The input jacks and voltage switch are protected by
being mounted on a recessed rear panel.
The reduced length and width of the test set allows it to be maneuvered in tight
spaces and it can be lowered into a shaft
26” x 30”, or a manhole 40” diameter.
Provisions have been made on the bottom of the frame for a lifting sling to be
attached without slipping from the corners.
GENERAL DESCRIPTION
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PI5000
The PI-5000 is composed of the PI2500 as described above, and the AUX-5000
auxiliary output unit, which when combined gives the unit the capability of
testing 4000 ampere breakers, with essentially the same specifications as the
proven PI-4000B. The auxiliary unit is smaller than the PI2500, so it can also be
maneuvered easily in tight spaces or lowered into shafts and manholes that
would not be possible with a larger single piece unit.
The AUX-5000 is easily attached to the PI-2500 by means of horizontal bus
bars with stainless steel socket head cap bolts and sturdy nutplates. The AUX-
5000 is simply rolled into place to mate with the PI-2500, and then the cap
screws are tightened. It is recommended to use a stubby fine pitch ratchet
wrench or a pneumatic air ratchet, with an Allen wrench hex bit.
