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4
Starting up & operation
Before commissioning, ensure that all Rotalock valves and other valves on the unit are fully
opened.
4.1
Charging procedure
4.1.1 Refrigerant charging procedure
It is recommended to charge the unit with refrigerant into the receiver, via the Rotalock service
valve.
Alternatively, it could also be done by charging gas through the suction valve of the compressor.
The charging procedure should follow the rules of art of refrigeration.
Recommendation is to break vacuum in the system with partial charge of refrigerant, then start the
system.
For charge adjustment it is recommended to check the liquid sight glass just before the expansion
valve.
4.1.2 Oil charging procedure
HLR Digital Receiver units are supplied only with a compressor oil charge. After commissioning,
the oil level should be checked and topped up if necessary.
NOTE: The oil level should be approximately halfway up the sight glass.
Emerson recommends charging the unit with one of the following oil types:
▪ Emkarate RL 32 3MAF
▪ Mobil EAL Artic 22 CC
Charging is done through the Schräder valve located on the suction Rotalock valve.
Two-compressor Digital Receiver units equipped with an oil separator are delivered with a small oil
can to add oil, if necessary.
4.2
Rotation direction of scroll compressors
Scroll compressors, like several other types of compressors, will only compress in one rotational
direction. The rotation direction is not an issue with single-phase compressors since they will
always start and run in the proper direction. Three-phase compressors will rotate in either direction
depending upon the power phasing. Since there is a 50-50 chance of connecting power in such a
way as to cause rotation in the reverse direction, it is important to include notices and
instructions in appropriate locations on the equipment to ensure proper rotation direction
when the system is installed and operated.
Observing that suction pressure drops and discharge pressure rises when the compressor is
energized allows verification of proper rotation direction. There is no negative impact on durability
caused by operating three-phase Scroll compressors in the reversed direction for a short period of
time (under one hour) but oil may be lost. After several minutes of operation in reverse, the
compressor's protection system will trip due to high motor temperature. However, if allowed to
repeatedly restart and run in reverse without correcting the situation, the compressor will be
permanently damaged.
All three-phase Scroll compressors are identically wired internally. Therefore, once the correct
phasing is determined for a specific system or installation, connecting properly phased power leads
to the identified compressor terminals in the electrical panel will ensure proper rotation direction.
4.3
Maximum compressor cycle
Maximum permitted starts per hour: 10.
It can be controlled via the EC2-552 controller (parameter t3, t4 and/or t5).
C6.1.7/1110-0519/E
15
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