User manual

10
ZX Platform Condensing Unit
Start Up and Operation
(1 second)-
>
- Power On
- Unit Identification Code
- Software Version No.
(3 seconds)-
>
(3 seconds)-
>
“F”-With OD Fan Speed Control; “-”- W/O OD Fan Speed Control
“-” - ZX; “L” - ZXL
LED 2
LED 1
Diagnostic Initialization Message (ZX-MT and ZXL-LT)
When the unit is initially powered on, the diagnostic module will show the following signals.
Before commissioning, ensure that all valves on the condensing unit are fully opened.
Evacuation
The evacuation procedure is based upon achieving an actual system vacuum standard and is not time dependent. Before the
installation is put into commission, it has to be evacuated with a vacuum pump. Proper evacuation reduces residual moisture
to 50ppm. The installation of adequately sized access valves at the furthest point from the compressor in the suction and liquid
lines is advisable. To achieve undisturbed operation, the compressor valves are closed and the system is evacuated down to
0.3 mbar / 0.225 Torr. Pressure must be measured using a vacuum pressure (Torr) gauge on the access valves and not on the
vacuum pump; this serves to avoid incorrect measurements resulting from the pressure gradient along the connecting lines to
the pump.
Charging procedure
Refrigerant charging procedure
The scroll compressor design requires system charging as quickly as possible with liquid refrigerant into the liquid line. This will
avoid running the compressor under conditions where there is insufficient suction gas. Sufficient suction gas is available to cool
not only the motor but also the scrolls. Temperature builds up very quickly in the scrolls if this is not done. Do not charge vapor
(gas) refrigerant into the ZX Scroll unit. The suction service valve must not be fully closed at any time while the compressor is
running. To do so would cause damage to the compressor in the same manner as explained above. This valve is provided for
ease of connection and for the fitting of service gauges without removing the unit panel. It is recommended to charge the ZX
unit with refrigerant via its service valves. It is recommended to break the vacuum in the system with a partial charge of the
refrigerant, before starting the system. For charge adjustment, it is recommended to check the liquid sight glass just before the
expansion valve.
Oil charging procedure
Emerson ZX condensing units are supplied only with a compressor oil charge. After commissioning, the oil level should be
checked and topped up if necessary. The oil level should be approximately halfway up the sight glass (ZXL/ZXD units). Oil can be
charged through the Schraeder valve on suction valve.
Scroll compressor rotation direction
Scroll compressors, like several other types of compressors, will only compress in one rotational direction. The direction of
rotation 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 phasing of the power. Since there is a 50-50 chance of
connecting power in such a way that causes 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.
Maximum compressor cycle
Maximum permitted starts per hour is 10.
Check before starting & during operation
Both valves should be fully opened on the liquid line, in order to prevent trapping liquid.
• Check that all valves are fully opened.
• After starting and operation conditions are stabilized, it is recommended to check the oil level in compressor(s) and see if
there is a need to add oil to ensure a sufficient oil level (halfway up the sight glass).