MECHANICAL
The PRIDEepackaging was designed for the maximum protection of the electronic components from the
electrical and natural envirorunent. '!be steel box is comparbnentalized as shown in Figure
7.
The inputs
and outputs enter the unit at the bottom in a Power Input compartment where the output relays and
transformers are mounted. This compartment contains no components that are sensitive to voltage
transients
or
electromagnetic interference (EM!).
ihe transient suppression required to meet the ANSI Surge Withstand capability and Fast Transient Test
is also located in the Power Input section.
The power and potential. transformers in this compartment
convert the
120
V
ac inl'lts to the lower levels used
by
the
PRIDE.
ihe
signals from the input section
PiSS
through EMI filters in an internal bulkhead before entering the Power Supply and Processor/Logic
section.
The EM! filters serve a dual pur[X)se. The external interference on the power and [X)tential inputs is
prevented from entering the sensitive circuit area.
Also, the inherent noise generated by the
microprocessor and switching regulator is prevented from leaving the relay and interfering with other
equipnent.
�CAUTIOH:
Do not apply any f o r m of t e s t equipment to c i r c u i ts w i th i n the
protected portion of the box.
In changing any cards w i thin this box, remove
a l l e x t e r nal v o l t a g e s .
Keep one h a n d o n the c a s e to d i s c h a r g e s t a t i c
electri c i ty before touching any o f the cards.
TEST BLOCKS
Most utilities have standardized on one of many different test blocks,
G.E.,
Westinghouse and States
being the most common. 'fuerefore, Beckwith Electric has not suWlied a test block on the PRIDE Unit,
thus enabling the user to incorporate his standard test block. This must be added external to the
PRIDE Unit.
-18-
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