Checking Tightness; Evacuation; Charging Refrigerant; Checks Prior To Compressor Start - Bitzer CSH6553-35Y Operating Instructions Manual

DANGER
Risk of bursting due to excessive pressure!
The pressure applied during the test must never
exceed the maximum permitted values!
Test pressure: 1.1-fold of the maximum allow-
able pressure (see name plate). Make a distinc-
tion between the high-pressure and low-pres-
sure sides!

4.2 Checking tightness

Check the refrigerant circuit (assembly) for tightness,
as a whole or in parts, according to EN378-2 (or other
applicable equivalent safety standards). For this, create
an excess pressure, preferably using dried nitrogen.
Observe test pressures and safety reference, see
chapter Checking pressure strength, page 46.

4.3 Evacuation

▶ Switch on the oil heater.
▶ Open all shut-off valves and solenoid valves.
▶ Use a vacuum pump to evacuate the entire system,
including the compressor, on the suction side and
the high-pressure side.
➙ With the vacuum pump shut off, a "standing vacuum"
lower than 1.5 mbar must be achieved.
▶ Repeat the operation several times if necessary.
NOTICE
!
!
Risk of damage to the motor and compressor!
Do not start the compressor while it is in a va-
cuum!
Do not apply any voltage, not even for testing!

4.4 Charging refrigerant

Use only permitted refrigerants, see chapter Application
ranges, page 44.
DANGER
Risk of bursting of components and pipes due to
hydraulic excess pressure while feeding liquid
refrigerant.
Serious injuries are possible.
Avoid overcharging the system with refrigerant
under all circumstances!
WARNING
Risk of bursting due to counterfeit refrigerants!
Serious injuries are possible!
Purchase refrigerants only from reputable man-
ufacturers and reliable distributors!
SB-170-10
NOTICE
!
!
Risk of wet operation during liquid feeding!
Measure out extremely precise quantities!
Maintain the discharge gas temperature at least
20 K above the condensing temperature.
Before charging with refrigerant:
▶ Do not switch on the compressor!
▶ Switch on the oil heater.
▶ Check the oil level in the compressor.
▶ Fill liquid refrigerant directly into the condenser or re-
ceiver; on systems with flooded evaporator, maybe
directly into the evaporator.
▶ Blends must be taken out of the charging cylinder as
a solid liquid.
▶ After commissioning, it may be necessary to add re-
frigerant: While the compressor is running, charge
with refrigerant on the suction side, preferably at the
evaporator inlet. Blends must be taken out of the
charging cylinder as a solid liquid.

4.5 Checks prior to compressor start

• Oil level (between the middle of the lower sight glass
and the upper area of the upper sight glass).
• During compressor start, oil temperature must be at
least 20°C and 20 K above ambient temperature –
that means approximately (at least) 15 K at the
measuring point directly under the oil sight glass.
• Setting and functions of safety and protection
devices.
• Setpoints of the time relays.
• Cut-out pressures of the high-pressure and low-pres-
sure switches.
• Check if the shut-off valves are opened.
In case of compressor replacement
Oil is already in the circuit. It may therefore be neces-
sary to drain off some oil.
NOTICE
!
!
In case of larger oil quantities in the refrigerant
circuit: Risk of liquid slugging when the com-
pressor starts!
Maintain the oil level within the marked sight
glass area!
47