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Trip values
fcr protective
circuits
arc @s follow::
OVerVG!?'Ug2 trips ai 130 V to 134 V
Undervo!ta~,;s
ir ips at 102 V or bc: low
Overfr~quency
trips at $15 Hz to
125
Hz
Undcrfrcquoncy
trip;
at 390 Hz to 395 Hz
Under-voltage
til;>2 delay
(adjustab!c)
4 to 12 !;oco:;d;
Overload
circuit
trips at any valtie
over
125% rated
loud capacity.
See Para.
7, H,
(3) fcr more specific
and detailed
information
regarding
over foad device.
(b)
Memcry
and time delay
module
The memcry
and time delay
module
(4) is sometimes
ca!Ied
the protective
mon itor module.
It is a solid-state
device
with a herrnet~cally-seaied,
reed-typa
relay.
The printed
circuit
board or "card"
includes
five
memory circuits
and a time defcy
circuit.
Each circuit
k connected
to a
corresponding
sensing circuit
in the sensing
modules
(5 and 6).
Ali
memory
circuit-s
are connected
to the module
relay
coil,
and any one of the cir-
cuits can energize
the coil
to open the relay
contacts.
Thus,
when a
sensing
device
energizes
any one of the module circuits,
the module relay
is also energized
to break
the load contactcr
holding
circuit
and allow
the
load contactoc'
to opan.
All
circuits,
except
the undervol:age
circuit,
function
immediately
to open the
load contactor.
A time deiaysplkm
is designed
into
the undervoltage
circuit
to prevent
nuisance
opening
of the contact=
under conditions
of momentary
undervoltage
in the gen-
erator
output.
An undervoltage
condition
which
cant inues uninterrupted
for a period
of 4 to 12second.s
(adjustable)
wiil
cause the time delay
circuit
to open the load contacts.
Each of the five circuits
is connected
to a corresponding
indicating
light
(10,
11,
13,
14 and 15) which
is turned
on when a fault
occurs.
The module relay
will
remain
energized
(OPEN)
and the light
will
remain
ON
until
the reset switch
(7) is pushed to break
the module
12-V
DC
circuit,
and allow
the relay
to return
to normal,
CLOSED
position.
(c)
Indicating
lights
The function
of these
lights
(10,
11,
13,
14 and 15) is to indicate,
to the
operator,
the abnormal
condition
of overvoltage,
undert?equency,
etc.,
which
caused
the protective
monitcc system'to
function.
Each of the five
lights
is connected
to an actuating
circuit
within
the memory and time
de lay module.
When
one of the circuiti
is activated,
it turns on the
Aug 25,185
l-1
Page 19
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