Install Instructions

Bulletin
No.
.l53.|039
RANSG@
DESCRI
PTION/APP
LICATION
Ranco
dual
pressure
controls
are
used
for
either
operating
or
protecting
commercial
ref rigeration
and air conditioning
systems.
Within one
NEMA
I enclosure, they
are
a
combination
of both
high
and
low
pressure
controls
interconnected
to
operate
a common
switch.
Ranco
dual
pressure
controls
are
suitable
lor R12,
R22,
and
R5O2
refrigerants
and are
available
with either
male
flare
or capillary
with
flare
nut
pressure
connections.
The
012,
with
a single
pole,
single
throw switch
(SPST),
will
directly
control
a single
phase
compressor;
the 012
may also
be
used
with a
contactorfor
pilot
control of single
and
three-phase
compressors.
The 022,
with
a
double
pole,
single
throw
switch
(DPST), will directly control
single
or three-phase
compressors.
The electrical
rati ngs inside
the
control
cover
must
not be
exceeded.
The
low
pressure
closes
(cuts-in)
the switch
on
nse of
compressor
suction
pressure
and opens
(cuts-out)
the
switch
on
pressure
drop.
The
high
pressure
function
overrides
to open
the switch
as the
compressor discharge
pressure
rises. See
page
3
for
Control
Adjustments.
Three
versions of
switch
operation
are available:
automatic
on both
low and
high
pressure;
manual
reset
on
both
low and
high
pressure;
and convertible
(manual
or automatic)
on
high
pressure
with automatic
on
low
pressure.
The converlible
reset
feature
allows the
high
pressure
side to
be changed
from manual to
automatic
reset
by
merely turning
the selector
screw.
O1AO22Dual
PRESSURE
CONTROL
ADJUSTMENT
SCREWS
INSTALLATION
CAUTION
To
prevent
possible
electrical
shock
or
equipment
damage,
disconnect
electrical
power
to unit before
and during
installation.
DO
NOT restore
electrical
power
to unit
until
the control
is
properly
installed
and
grounded. DO NOT
locate
the control
in an
expfosive
atmosphere
as a
safety
hazard
can
result
due
to
possible
spark
generation
in
the control.
Controls are
not to
be
located
in areas of
extreme
moisture, dirt
or dust,
or
in a
corrosive
or explosive
atmosphere.
These
environments
can shorten
control
life.
CONVERTIBLE
SELECTOR
RESET
S6REW
BUrroN
I
\-
I
DIFFERENTIAL
\-
LADJUSTMENT
\-
\-.
|
-Z
sc*Ew
RANGE
\
''
IMPORTANT
NOTICE
MANUAL
OPERATION
(tripping
switch)
The switch
can be
manually closed
by
lifting
the
bellows tab on the
low
pressure
side,
provided
that
the system
high
pressure
is
below
the high
pressure
cut-in.
Cycltlg-the
control
at any other
point
WILL CAUSE
CONTROL
DAMAGE
AND VOIDS
WARRANTY.
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\
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NOf
t
\
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