Expansion Valve Selection For Low Ambient Application; Location And Fixing - Emerson Copeland Scroll 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.
1029
70
300
1029
300 70 70
16
500
Power
Supply Hole
Suction
Service Valve
Liquid
Service Valve
23
70 500
Fixing dimensions and distances - Single fan unit
500
Power
Supply Hole
Suction
Service Valve
Liquid
Service Valve
23
500
Fixing dimensions and distances - Dual fan unit
352 300
94
2-R7.5MM GROOVE
424
352 300
94
2-R7.5MM GROOVE
424
2 Holes 15mm DIA
580
Single Fan Unit
2 to 4 HP
2 Holes 15mm DIA
580
Dual Fan Unit
4 to 7.6 HP