25
Evaporating
pressure
control
This
control
is
carried
out
by
a
low
pressure
switch.
During
rise
pressure,
this
pressure
engage
and
induce
the
starting
of
compressor
if
the
safety
line
is
closed.
Condensing
pressure
control
This
control
is
carried
out
by
a
fan
speed
control
which
can
cut
or
fluctuate
fan
power
supply
(see
operating
instructions
of
the
fan
speed
control).
ELECTRONIC
REMOTE
CONTROL
(option)
Remote
control
for
unit
with
electronic
room
control.
120
Temperature
regulation
sensor
to
be
placed
on
the
air
inlet
of
the
evaporator.
3-
START-UP
OPERATIONS
PRELIMINARY
CHECKS
AND
OPERATIONS
General
information
Ensure
that
all
the
threads
are
fully
tightened
on
connection
flanges,
flexible
connections
and
cables
as
jolting
during
transport
could
cause
screws
and
bolts
to
loosen.
Check
also,
for
same
reasons,
if
there
are
any
breaks
in
the
piping.
Ensure
that
the
flexible
connections
are
not
in
contact
with
metal
parts.
Vibrations
from
the
compressor
can
cause
wear
in
these
until
they
rupture
at
the
point
of
friction.
Switch
on
crankcase
heaters
24
hours
before
start-up.
Check
that
the
condenser
fans
turn
freely.
Operating
instructions
during
maintenance
During
all
operations,
the
following
operating
instructions
must
be
followed:
-
Unit
door
must
only
be
opened
after
the
main
switch
is
cut-off
and
the
fans
have
completely
stopped.
-
The
safety
HP
and
LP
switches,
fans
speed
control
and
control
LP
switch
can
be
accessed
when
the
door
is
opened.
-
Then,
access
to
pressure
plug
for
connecting
the
pressure
gauge
is
possible.
Pressure
gauge
cables
go
across
holes
on
the
housing.
Following
this
operating
mode
allows
unit
tests
to
be
carried
out
with
the
door
closed,
ensuring
operators’
safety
as
well
as
the
correct
running
of
thedevice.
Determining
the
compressor
rotation
direction
Important:
Scroll
compressors
only
have
one
rotation
direction.
Any
rotation
in
the
opposite
sense
may
lead to a compressor
destruction.
During
the
first
start
up,
it
is
absolutely
necessary
to
determine
the
phases
connections
to
compressor
terminals.
That
handling
must
be
tactful
with
hermetic
compressors
and
must
be
extremely
fast
(less
than
1
second).
-
Place
a
LP
pressure
gauge
at
the
schraeder
valve
of
LP
pressure
switch.
-
Start
up
the
compressor
with
the
start
button
-
As
soon
as
it
is
started,
stop
the
compressor
(this
handling
must
take
some
seconds)
-
During
that
time,
if
the
pressure
gauge
showed
that
the
pressure
went
down,
the
rotation
direction
is
correct.
-
In
the
opposite
case,
invert
the
2
phases
on
the
compressor
breaker
and
repeat
the
same
operation
for
checking.
Leaks
testing
Pressurise
the
whole
system,
including
the
condensing
unit,
using
a
neutral
gas
(Nitrogen)
with
a
(non-liquid,
non-colouring)
tracer,
at
a
minimum
pressure
of
10
bars
and
at
a
maximum
pressure
of
less
than
20.5
bars,
isolating
the
LP
(low
pressure)
switches.
Summary of Contents for QUIETOR GQH-GQL
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