Expansion Valve Selection For Low Ambient Application; Location And Fixing - Emerson CopelandScroll ZX 401 User Manual

Expansion Valve Selection for Low Ambient Application

For systems expected to operate in varying ambient conditions – namely summer and winter temperatures – the expansion valve (TXV
or EXV) sizing should take into consideration the maximum expected saturated condensing temperature at high ambient conditions
(summer) and the minimum expected saturated condensing temperature, set at -25°C, during low ambient conditions (winter).
The chosen expansion valve's operating capacities should be well within these limits to ensure satisfactory system performance.
In the event that different expansion valves come up for the two conditions, the valve for low ambient condition should be
selected. This means that at higher ambient, the valve will be oversized. However, if the valve at the high ambient is selected, it
may be too small during low ambient condition.

Location and Fixing

The unit should always be installed in a location that ensures clean air flow. It is recommended that a clearance of 300 mm from the wall
(or the next unit) be maintained from the unit's left and rear panels whereas a clearance of 500 mm must be maintained from the unit's
right, top and front panels (seen facing the front of the unit). Both service access and airflow have been considered in making these
recommendations. Where multiple units are to be installed in the same location, the contractor needs to consider each individual case
carefully. There can be many variations of unit quantities and available space and it is not the intention of this manual to go over these.
Ideally, the unit should be mounted on a solid concrete slab with anti-vibration pads between unit feet and concrete. However the ZX
condensing unit has also been designed for wall mounting on suitable brackets. Wall mounting brackets are not included. Another factor
to consider in finding a good installation site is the direction of the prevailing wind. For example if the air leaving the condenser faces
the prevailing wind, the air flow through the condenser can be impeded, causing high condensing temperatures ultimately resulting in
reducing unit life. A baffle is a remedy for this situation.
500
1029
840
70
300
500
1029
1242
300 70
500
21
Power Supply Hole
Suction Service Valve
Liquid Service Valve
23
70 500
Fixing dimensions and distances - Single fan unit
500
21
Power Supply Hole
Suction Service Valve
Liquid Service Valve
23
500
70
Fixing dimensions and distances - Dual fan unit
352 300
388
2-R7.5MM GROOVE
172
90
424
352 300
388
2-R7.5MM GROOVE
94
172
90
424
2 HOLESØ15MM DIA
110
580
2 HOLESØ15MM DIA
110
580
17