29/61
Fan
checks
Direction
of
rotation
Check
that
the
fans
are
rotating
in
the
correct
direction,
i.e.
drawing
on
the
coil.
Pre-Setting
And
Checking
of
Safety
Systems
-
Pre-set
the
HP/LP
(compressor
safely)
pressure
switches
and
test
manually.
-
Pre-set
the
HP
regulation
pressure
switch
and
test
manually..
The
condensation
pressure
is
regulated
through
a
HP
(High
Pressure)
pressure
switch
that
starts
the
fan
motors
according
to
the
setting
chosen.
Every
possible
measure
should
be
taken
in
order
to
avoid
short
circuit.
Maximum
15
cycles
per
hour.
Device
Elect.
Symb
Function
Fluid
Applicati
on
Recommended
settings
HP/LP
pressure
switch
HP/LP
Compressor
safety
device
R22
R404A
Positive
Negative
Cut
out
:
24
bar
Cut
in
:
18
bar
Compressor
safety
device
R22
Positive
Cut
out
:
1
bar
Cut
in:
3
bar
R404A
Positive
Cut
out
:
1,5
bar
Cut
in
:4
bar
R404A
Negative Cut
out
:
0,2
bar
Cut
in
:
1,5
bar
Important:
The
pressure
sensors
are
on
the
compressor
valves
and
the
valve
opening
should
be
left
connected
to
the
circuit
(1/4
T).
START-UP
Start
up
of
condensing
unit
-
Open
all
the
valves
(compressor
suction
and
discharge
in
liquid
bottle)
-
Place
an
ammeter
on
one
phase
of
the
compressor
-
Close
the
power
circuit-breaker
or
the
fan
motor
cut-outs.
-
Start
up
compressor
by
switching
the
on/off
switch
to
on.
The
current
increases
to
maximum
and
should
decrease
very
rapidly.
If
this
does
not
happen,
stop
the
compressor
to
check
and
find
the
fault.
The
condenser
fans
should
cut
in
automatically
according
to
the
pre-set
set
points.
Remainder
of
charge
Fill
up
with
the
remainder
very
quickly.
An
incomplete
charge
of
fluid
will
cause
considerable
superheat
and
so
abnormally
high
discharge
temperatures.
OPERATING
CHECKS
Shortly
after
start-up,
the
operating
conditions
of
the
equipment
must
be
checked.
Compressor
-
The
compressor
must
operate
within
its
acceptable
limits
(see
Manufacturer's
advice).
-
Check
on
each
compressor:
Voltage
