Install Instructions
INSTRUCTION
SHEET
NO.
1531006
RANSG@
ELECTRICAL
RATINGS
VAC FLA
LRA
NIA P.D.. VA
120
240
277
20
20
16
80
80
60
25
25
18
500
500
500
APPLICATION
The
function
of theA22 control
is
to cycle
a SPST or SPDT
switch
in response
to changes
of temperature.
The
temperature
sensing
element
consists
of an appropriate
charge
bellows assembly
for accurate
temperature control.
fhe
A22 control
is
used
for the
lollowing applications:
*
Beverage
Coolers
'Water
Coolers
'
Room
Air Conditioning
*
lce Harvest
Control
*
lce
Bin Level Control
*
Heat Pumps
(Manual
Changeover)
*
Two Speed Condenser
Fan
Control
'
Signal or
Alarm Circuits
*
Defrost Cycles
(Wide
Ditferentials)
OPERATION
Switch
is operated
by the expansion
and contraction
of
the
bellows
in response to temperature
changes
Switch
terminals
#2 and
#1
CLOSE
on
DROP, and terminals
#2
and
#3 CLOSE
on RISE
Terminal
#2
is common.
(See
Figure
1)
CLOSE
ON
FISE OF
TEMPERATURE
CLOSE ON
DROP OF
IEMPEFATURE
SWITCH TERMINAL
WIRING
Figure 1
lf single
throw
action is used,
the A22 control will
have
one terminal
(#2
or
#3) omitted, depending on the
functionalapplication
the
A22 control
is to be applied.
NOTE
: Should
a loss
in
bellows
charge occur,
terminals
#2 and
#1 will close. At operating
temperatures
the bellows
pressure
exceeds
atmospheric
pressure,
thereby contracting
the
bellows upon
loss ol fillto open the
circuit to terminals
#2 and
#3.
azzlilaRtable
G0ld
Gontrol.
SPIII
/
SPSI
'
A22
-
1129
Direct Replacement
For lce
Machines
,A
sf$
RANGE
ADJUSTMENTS
are
limited to
the
rotation of
the
dial for the
required
temperature
set
point
needed
by the
user.
However,
limited
altitude
corrections
can be
made on initial
installation
by
using
the
range screw
under the
end
cover.
DIFFERENTIAL
SCREW
ADJUSTMENT,
in the
insulator btiJck,
is for
factory calfl:ration
use only,
and is
NOT to be adjusted
in the
field.
DIFFERENTIAL
SCREW
ADJUSTMENT2SCREWS
TEMPERATURE
SENSlnd
eueueNTS
are of two
types
(1)
LIMITED
VAPOR-PRESSURE
fillto
operate
from
the
coldest
point (2)
CROSS
AMBIENT
fill to operate
f
rom
the
bulb
location only.
lt
is impodant that
capillary
and bulbs
not be cut, kinked
or
pinched
in mounting
to unit elements
Also,
ensure
tubing
clamps
and
wells are
of compatible
material with
the control
sensing
element
to
prevent
corrosion.
VAPOR
-
PRESSURE
filled capillaries
can be
formed
to
various bulb types
to
match
the original
control
being
replaced. Use RANCO
bulb
forming
tool, Catalog
number
57963-1
for
your
bulb
forming
requirements
CROSS
AMBIENT
bulb's
dimension
will be
3/8" OD. X 4"
size bulbs
with the
word
"TOP" stamped
on the
bulb. The
bulb must be
mounted
with
word
'TOP'
up
when
in
horizontal
position.
Bulbs
with
1/4" OD. X 6s/8"
must be
mounted
with lill" tube
straight
up or to
within 65 of
vertical.