Checks Prior To Compressor Start; Compressor Start; Checking The Rotation Direction - Bitzer CSH6553-35Y Instructions De Service

• 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.

6.5 Checks prior to compressor start

• Oil level (in the upper zone of the sight glass).
• During compressor start, oil temperature must be at
least 20°C and 20 K above the 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 pressure values of the high-pressure and
low-pressure limiter.
• 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!
When a reciprocating compressor is replaced:
• Completely remove the oil from the system. The new
oil is not only more viscose. It is an ester oil with
other chemical and physical properties.
NOTICE
!
!
Risk of damage to the compressor!
The new oil has a great cleaning effect in the re-
frigerant circuit.
On the suction side, mount a cleaning filter suit-
able for bidirectional operation!
Mesh size: 25 µm
• Mount a filter for bidirectional operation with perfor-
ated metal tubes around the inside and outside dia-
meter of the filter element.
• After several operating hours: Change the oil and
cleaning filters.
SB-170-7
• If needed, repeat the operation, see chapter Oil
change, page 49.

6.6 Compressor start

6.6.1

Checking the rotation direction

NOTICE
!
!
Risk of compressor failure!
Operate the compressor only in the intended ro-
tation direction!
Even if the protection device SE-E1 or the optional pro-
tection device SE-i1 monitors the rotating field, a test is
recommended:
Rotation direction test with integrated suction shut-off
valve:
• Connect the pressure gauge to the suction shut-off
valve. Close the valve spindle and open again by
one turn.
• Let the compressor start shortly (approximately 0.5 ..
1 s).
• Correct rotation direction: Suction pressure drops im-
mediately.
• Incorrect rotation direction: Suction pressure in-
creases or protection device shuts off.
• Incorrect rotation direction: Change the poles of the
terminals on the common feed line.
Direction rotation test without suction shut-off valve:
• Close the solenoid valves on the evaporator and the
economiser. The pressure changes measured in
such a case are much lower than with throttled suc-
tion shut-off valve!
• Let the compressor start shortly (approximately 0.5 ..
1 s).
• Correct rotation direction: Suction pressure drops a
bit.
• Incorrect rotation direction: Suction pressure stays
the same or increases a bit, or protection device
shuts off.
• Incorrect rotation direction: Change the poles of the
terminals on the common feed line.
After the rotation direction test:
• Let the compressor start while opening slowly the
suction shut-off valve.
47