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4
4--1
15
5
6
62
2----6
61
11
1X
XX
X----2
20
0 ((0
03
3//0
04
4))
1.
1. Cylin
Cylinder
dervalve
valve and
and gau
gauge
ge
2.
2. Pressu
Pressure
re reg
regula
ulator
tor
3.
3. Nitr
Nitroge
ogen
n cylin
cylinder
der
4.
4. Pressu
Pressure
re gau
gauge
ge
(0 to 400 psig = 0 to 28 kg/cm
(0 to 400 psig = 0 to 28 kg/cm
2
2
))
5.
5. Blee
Bleed-Of
d-Off f valve
valve
6.
6. 1/4
1/4 inch
inch conn
connectio
ection
n
1.
1.
2.
2.
3.
3.
4.
4.
5.
5.
6.
6.
Figure 4-1
Figure 4-10
0 Ty
Typical set
pical setup for testing high
up for testing high
pressure switch
pressure switch
a.
a.
Remove switc
Remove switch as outlined in section 4.13.1.
h as outlined in section 4.13.1.
b.
b.
Conne
Connect ohmmeter or
ct ohmmeter or contin
continuity light across switch
uity light across switch
termina
terminals.
ls. Ohmmete
Ohmmeter
r will indicate resistanc
will indicate resistance and
e and
continuity light will be lighted if switch closed after
continuity light will be lighted if switch closed after
relieving pressure.
relieving pressure.
c.
c.
Connect switch to a cylinder of dry nitrogen (see
Connect switch to a cylinder of dry nitrogen (see
Figure 4-10).
Figure 4-10).
d.
d.
Set nitrogen pressure regulator higher than cutout
Set nitrogen pressure regulator higher than cutout
poi
point
nt on
on swi
switch
tch bei
being te
ng tested
sted.. Pres
Pressur
sure swi
e switch
tch cuto
cutout
ut
and cut-in points are shown in section 2.3.
and cut-in points are shown in section 2.3.
e.
e.
Close valve on cylinder and open bleed-off valve.
Close valve on cylinder and open bleed-off valve.
f.
f.
Open cylinder valve. Slowly close bleed-of
Open cylinder valve. Slowly close bleed-off valve
f valve
and incre
and increase press
ase pressure until the s
ure until the switch
witch opens
opens. If
. If light
light
is used, light will go
is used, light will go out and if
out and if an ohmmete
an ohmmeter is
r is used,
used,
the
the me
meter
ter wi
will
ll in
indi
dica
cate
te op
open
en. . Ope
Open
n pre
pressu
ssure
re on
on
gau
gauge.
ge. Slo
Slowly
wly ope
open
n ble
bleed-
ed-off
off val
valve
ve (to
(to dec
decrea
rease
se
pre
press
ssur
ure)
e) un
until
til sw
switc
itch
h cl
clos
oses
es (l
(lig
ight
ht wi
will
ll liligh
ght t or
or
ohmmeter will move).
ohmmeter will move).
4.14
4.14 CHE
CHECKIN
CKING AN
G AND RE
D REPLACI
PLACING LOW
NG LOW
PRESSURE CUTOUT SWITCH
PRESSURE CUTOUT SWITCH
4.1
4.14.1
4.1
Rep
Replac
lacing
ing low
low pre
pressu
ssure
re swi
switch
tch
a.
a.
Unplug
Unplug
b.
b.
Unscrew
Unscrew
c.
c.
Calibr
Calibrate new sensor (refer to section 3.18.4)
ate new sensor (refer to section 3.18.4)
d.
d.
Screw into place
Screw into place
e.
e.
Connect
Connect
4.1
4.14.2
4.2
Che
Checki
cking
ng low
low pre
pressu
ssure
re swit
switch
ch
a.
a.
Start the unit after having instal
Start the unit after having installed a manometer on
led a manometer on
compressor.
compressor.
b.
b.
Close receiv
Close receiver valve to
er valve to pump down suction line.
pump down suction line.
c.
c.
Using an ohmmeter or continuity light, verify that
Using an ohmmeter or continuity light, verify that
switch opens or
switch opens or closes accordi
closes according to
ng to speci
specification
fication..
d.
d.
Repeat checkout procedure until switch actuates at
Repeat checkout procedure until switch actuates at
correct gauge reading.
correct gauge reading.
e.
e.
After switch is adjusted, place a small amount of
After switch is adjusted, place a small amount of
pa
pain
int t or
or gl
glyc
ycero
erol l on
on the
the ad
adju
justi
sting
ng scr
screw
ew so
so tha
thatt
vibrati
vibration will
on will not change switch
not change switch setting
setting..
4.15
4.15 REPLA
REPLACING
CING RECE
RECEIVER
IVER SIGHT
SIGHT GLASS
GLASS
ASSEMBLY
ASSEMBLY
NOTE
NOTE
There are two types of receiver sight glasses; the
There are two types of receiver sight glasses; the
fl
floa
oati
ting
ng ba
ball
ll ty
type
pe,
, an
and
d th
the
e pr
pris
ism
m ty
type
pe;
; bo
both
th ar
are
e
interchaneable.
interchaneable.
a.
a.
Store
Store the
the refri
refriger
gerant
ant in
in an
an eva
evacua
cuated
ted con
contain
tainer
er..
(Refer to Section 3.5b)
(Refer to Section 3.5b)
b.
b.
Unscre
Unscrew
w the sight
the sight glass assembly
glass assembly. . Spread some
Spread some
sea
sealin
ling
g com
compou
pound
nd on
on pip
pipe
e thre
threads
adsof
of new
new sig
sight
ht gla
glass
ss
assembly and install.
assembly and install.
c.
c.
Leak check recei
Leak check receiver sight glass per Section 3.6.
ver sight glass per Section 3.6.
d.
d.
After
After lea
leak chec
k checkin
king
g uni
unit, evac
t, evacuate
uate and de
and dehyd
hydrate
rate as
as
outlin
outlined in
ed in section 3.7.
section 3.7.
e.
e.
Add refrigera
Add refrigerant charge. (Refer to section 3.8).
nt charge. (Refer to section 3.8).
f.
f.
Check for
Check for noncondensibles.
noncondensibles.
4.1
4.16
6 COI
COILS
LS CLE
CLEAN
ANING
ING
4.
4.16
16.1
.1
Ev
Evap
apora
orator
tor co
coil
il
The use of
The use of recyc
recycled cardboa
led cardboard cartons is
rd cartons is increa
increasing
sing
across the
across the country
country. . The recycled
The recycled cardbo
cardboard cartons
ard cartons
cre
create
ate muc
much
h more
more fib
fiber
er dus
dustt dur
during
ingtran
transpo
sport
rt tha
than
n “ne
“new”
w”
cartons
cartons. . The fiber dust
The fiber dust and particles are drawn into the
and particles are drawn into the
evaporator where they lodge between the evaporator
evaporator where they lodge between the evaporator
fin
fins.
s. If
If the coil is
the coil is no
not t cl
clea
eane
ned
d on a
on a reg
regul
ular basi
ar basis,
s,
so
some
metim
times
es as
as oft
often
en as
as af
after
ter ea
each
ch tri
trip,
p, the
the ac
accu
cumu
mula
latio
tion
n
can
can be
be gre
great
at eno
enough
ugh to
to res
restric
trictt air
air flow
flow,, cau
cause
se coi
coill ici
icing,
ng,
repetitive defrosts and loss of unit capacity. Due to the
repetitive defrosts and loss of unit capacity. Due to the
“washing” action of normal defrost the fiber dust and
“washing” action of normal defrost the fiber dust and
particles may not be visible on the face of the coil but
particles may not be visible on the face of the coil but
may accumulate deep within.
may accumulate deep within.