Charging Refrigerant; Checks Prior To Compressor Start - Bitzer ORBIT 6 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!

6.4 Charging refrigerant

Use only permitted refrigerants, see chapter Application
ranges, page 24.
• Before charging with refrigerant:
– Do not switch on the compressor!
– 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.
• Before starting, pre-fill the system so that operation
within the application limits is possible.
• During the filling process, operation below 2.4 bar
(excess pressure) is possible for short periods, while
maintaining the condensing temperature low. While
doing so, the time delay of the low-pressure limiter
may only be activated once.
• 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.
• For each system, controlled tests must be performed
to determine the optimum refrigerant charge, to
achieve the best possible operating conditions and
to prevent the liquid refrigerant from flowing back to
the compressor.
• Blends must be taken out of the charging cylinder as
a solid liquid.
NOTICE
!
!
Risk of wet operation during liquid feeding!
Measure out extremely precise quantities!
Maintain the discharge gas temperature at least
30 K above the condensing temperature.
NOTICE
!
!
Lack of refrigerant causes low suction pressure
and superheat condition!
Observe the application limits.
36
WARNING
Risk of bursting due to counterfeit refrigerants!
Serious injuries are possible!
Purchase refrigerants only from reputable man-
ufacturers and reliable distributors!
DANGER
Risk of bursting of components and pipelines
due to hydraulic excess pressure while feeding
liquid.
Serious injuries are possible.
Avoid overcharging the system with refrigerant
under all circumstances!

6.5 Checks prior to compressor start

• Oil level (within the marked sight glass area)
• Oil temperature (at least 10 K above ambient tem-
perature or suction-side saturation temperature)
• Setting and functions of safety and protection
devices.
• Setpoints of the time relays
• Cut-out pressure values of the high-pressure and
low-pressure limiter
• Check the cable lugs for tight seat and correct posi-
tion.
• Shut-off valves opened?
The performance of scroll compressors increases dur-
ing the running-in period. Special running-in conditions
must be complied with when testing the performance of
ORBIT scrolls. For details see the BITZER Software.
NOTICE
!
!
Risk of motor and compressor failure!
In the event of lack of refrigerant or malfunction
of refrigerant injection into the compressor,
scroll compressors may generate a vacuum on
the suction side.
Adjust the low-pressure limiter accordingly and
check its function before commissioning.
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!
ESB-130-8