Preliminary Checks - Pre-Starting; Charging Procedure - Emerson Copeland Scroll YH04K1E Application Manuallines

Evacuating the system only on the suction side of a scroll compressor can occasionally result in a
temporary no-start condition for the compressor. The reason for this is that the floating seal could
axially seal with the scroll set, with the higher pressure on the floating seal. Consequently, until the
pressures equalise, the floating seal and scroll set can be held tightly together.
The highest demands are placed on the leak-proof design of the installation and on the leak testing
methods – please refer to EN 378.
Preliminary checks – Pre-starting
5.4
WARNING
Air/A2L refrigerant mixture in a potentially flammable or explosive
atmosphere! Fire and explosion hazard! Whenever starting up a system
charged with A2L refrigerant, eg, after filling, repair, or maintenance, make
sure not to start and operate accidentally in a flammable or explosive
atmosphere.
Discuss details of the installation with the installer. If possible, obtain drawings, wiring diagrams, etc.
It is ideal to use a check-list but always check the following:
▪ no explosive atmosphere or flammable gas in the ambient;
▪ suitable ventilation according to the room volume and to the refrigerant charge;
▪ visual check of the electrics, wiring, fuses etc;
▪ visual check of the plant for leaks, loose fittings such as TXV bulbs etc;
▪ compressor oil level;
▪ calibration of HP & LP switches and any pressure-actuated valves;
▪ check setting and operation of all safety features and protection devices;
▪ all valves in the correct running position;
▪ pressure and compound gauges fitted;
▪ correctly charged with refrigerant;
▪ compressor electrical isolator location & position.
5.5

Charging procedure

WARNING
Air/A2L refrigerant mixture in a potentially flammable or explosive
atmosphere! Fire and explosion hazard! Only use filling equipment
designed and approved for use and operation with A2L refrigerants. Make
sure all connections are tight to avoid leakage. Make sure to fill with pure A2L
refrigerant.
CAUTION
Low suction pressure operation! Compressor damage! Do not operate
with a restricted suction. Do not operate with the low-pressure limiter bridged.
Do not operate compressor at pressures that are not allowed by the operating
envelope. Allowing the suction pressure to drop below the envelope limit for
more than a few seconds may overheat scrolls and cause early drive bearing
and moving parts damage.
Prior to charging or re-charging, the system must be leak- and pressure-tested with appropriate
purging gas.
Ensure that the refrigerant system is grounded prior to charging with refrigerant.
The system shall be liquid-charged through the liquid-receiver shut-off valve or through a valve in
the liquid line. The use of a filter drier in the charging line is highly recommended. Systems shall be
liquid-charged on both the high and low sides simultaneously to ensure a positive refrigerant
pressure is present in the compressor before it runs. The majority of the charge shall be placed in
the high side of the system to prevent bearing washout during first-time start on the assembly line.
Extreme care shall be taken not to overfill the refrigerant system.
The system manufacturer/installer must respect the charge limitations according to valid standards,
such as EN 378.
AGL_HP_ST_YHK1E_E_Rev02 21