Cooling Connections - Carrier 38ZS/ZF Installation, Operation And Maintenance Instructions

7 - CHECKING BEFORE COMMISSIONING

7.2 Cooling connections

Once installed the outdoor and indoor units, the cooling links
must be laid between them.
Cooling
90 100 120 160 180 182 200 240 320 360 420 485 540 600
connections
Circuit 1:
1/2" 1/2" 5/8" 5/8" 5/8" 5/8" 1/2" 5/8" 5/8" 5/8" 5/8" 5/8" 7/8" 7/8"
Liquid line
Circuit 1: 1 1 1 1
7/8"
Gas line
1/8" 1/8" 1/8" 1/8"
Circuit 2:
-- -- -- -- --
Liquid line
Circuit 2:
-- -- -- -- --
Gas line
The maximum equivalent length of the cooling line is 50 metres,
with a maximum geometric height of 40 metres when the outdoor
unit is high. For longer distances, up to 100 metres maximum, an
oil separator must be used per cooling circuit. If it is the indoor
unit which is high, the maximum equivalent length is reduced
to 7 metres.
Outdoor unit top
Maximum equivalent length of the cooling line: 50 metres
For longer lenghts, up to 100 metres maximum,
an oil separator must be user
38ZS/ZF
outdoor
unit
L: liquid line
G: gas line
Siphon in gas line for every
3 metres of drop
Expansion
exchanger device
(connected on-site)
Outdoor unit bottom
Maximum equivalent length of the cooling line: 7 metres
L: liquid line
G: gas line
Siphon in gas line for every
3 metres of drop
Expansion
exchanger device
(connected on-site)
It is recommended to place a siphon in the gas line every 3
meters of shoulder to ease the oil return to the compressor.
1 1 1 1 1 1 1 1
1/8" 1/8" 1/8" 1/8" 1/8" 1/8" 1/8" 1/8"
-- 1/2" 5/8" 5/8" 5/8" 5/8" 5/8" 5/8" 7/8"
1 1 1 1 1 1 1
--
1/8" 1/8" 1/8" 1/8" 1/8" 1/8" 1/8"
L G
38ZS/ZF
outdoor
G L
unit
For determining the equivalent length, the pressure
drops in accessories must be taken into account.
Pressure drops in elbows expressed as equivalent lengths
(m):
Tube installation norms must be
1
respected and inspect carefully the tube
1/8"
lay out, looking for the shortest distance
and the lowest possible number of
1
curves. Also, chokes must be avoided,
1/8"
using large curve radii (the curve radius


must be ≥ 3,5x
Tube diameter (inches)
Equivalent elbow length 45º (m)
Equivalent elbow length 90º (m)
Equivalent elbow length 180º (m)
Connection of the unit to the cooling lines
For the refrigerant lines, use only cooling type seamless tubes.
Under no circumstance use sanitary type copper pipe.
Following these steps is recommended:
● Revise and clean the tube ends to eliminate the burs from
cutting them and any other impurity that could have deposited
inside or on the outer surface. How clean the tubes are will
dictate the degree or air tightness. Also, we will avoid the dirt
formation that may collapse some spots in the cooling circuit.
● Apply isolator to the piping, covering them and affi x it with
tape. The material used must guarantee the air tightness at
operation pressure and temperature.
● Remove the plugs that protect the cooling connections of the
unit precisely at the moment of connecting the tubes.
● Align precisely both parts of the connection (unit and
piping). There is no error risk when both tubes have diff erent
diameters.
● Run a pressure test in the cooling tubes and a search for leaks
to verify the cooling installation.
● Create a vacuum in the installation to eliminate humidity inside
the circuit.
● Charge the unit with gas as per the data stated in a table of
the chapter "Maintenance" and in the unit's data plate. Add
the refrigerant slowly via charging valve (schrader type) built
into the liquid line of each circuit with compressors stopped,
and using the appropiate tools monitoring the pressures to
detect if there are any possible anomalies.
Note: Optionally these units can be supplies with service
valves and refrigerant load for cooling connections (up to 7,5
meters long).
● If the equivalent length of the cooling lines is over 7 m, an
additional charge will be needed per meter as per the following
table.
Nominal diameter (")
Indoor section (cm )
2
Liquid line charge (g/m)
Gas line charge (g/m)
Note: To ensure that the gas charge is correct, follow the
instructions given in chapter "Commissioning".
1/2" 5/8" 7/8"
0,24 0,30 0,39
0,45 0,54 0,72
0,75 0,80 1,00
1/4" 3/8" 1/2" 5/8" 3/4" 7/8"
0,149 0,444 0,900 1,505 2,282 3,120 4,290 5,346
19,3 57,0 115,0 193,5 292,3 404,1 550,3 685,7
- 0,2 0,4 0,7 1,0 1,4
Æ
1 1/8"
0,48
0,90
1,30
1" 1 1/8"
2,0 2,5
13