Lennox AIRCOOLAIR KNCK 24E, Installation, Operation & Maintenance Manual, Page: 16 / 28

PRECAUTIONS TO BE TAKEN IN THE USE OF R-407C Refrigerant:
R-407C Refrigerant is used in the unit; therefore, the following precautions characteristic of this gas
should be taken:
- The Vacuum Pump must have a Check Valve or Solenoid Valve.
- Pressure Gauges and Hoses for the exclusive use with R-407C Refrigerant should be used.
- The charge should be carried out in the Liquid Phase.
- Always use scales to weight-in charge
- Use the Leak Detector exclusive for R-407C Refrigerant.
- Do not use mineral oil, only synthetic oil to ream, expand or make connections.
- Keep pipes wrapped before using them and be very thorough about any possible dirt (dust, filings,
burrs, etc.).
- When there is a leak, gather what is left of the charge, create a vacuum in the unit and completely
recharge with new R-407C Refrigerant.
- Brazing should always be carried out in a nitrogen atmosphere.
- Reamers should always be well sharpened.
15
NOTE: The units are supplied with welded connections.
As an option , service valves are available for liquid
and gas lines; in this case:
1
st Remove the pressure of refrigerant from the
connecting line through the service port located on
that line.
2
nd Remove the covers from the connecting lines.
3 rd Braze the piping connection lines to the indoor unit.
The units are supplied with welded connections. As an option, the unit can be supplied with refrigerant factory
precharged; in that case, only TABLE 2 is important (this option includes service valves).
FROM 0 TO 10M FROM 30 TO 50M FROM 10 TO 30M
MODEL 24E
MODEL 32E
MODEL 38E
MODELS 48D / D2
5/8"
3/4"
7/8"
1-1/8"
1-5/8"
155
155
232
327
2x155
2x155
1-1/8"
1-3/8"
2x1-1/8"
2x1-1/8"
5/8"
2x5/8"
2x5/8"
3/4"
7/8"
1-5/8"
232
232
327
340
2x232
2x232
2-1/8"
7/8"
1-3/8"
1-3/8"
2x1-3/8"
2x1-3/8"
3/4"
2x3/4"
2x3/4"
Suction Liquid Suction Liquid
TABLE 2: CHARGE OF REFRIGERANT R-407C PER METER OF COPPER LINE
gr/m gr/m
2x232 2x1-3/8" 2x3/4" 2x327 2x1-5/8" 2x7/8"
MODELS 64D / D2
2x327 2x1-5/8" 2x7/8" 2x340 2x2-1/8" 2x7/8"
MODELS 76D / D2
MODELS 86D / D2
5/8"
7/8"
7/8"
1-1/8"
1-5/8"
155
232
327
327
2x155
2x232
1-3/8"
1-5/8"
2x1-1/8"
2x1-3/8"
3/4"
2x5/8"
2x3/4"
Suction Liquid gr/m
2x327 2x1-5/8" 2x7/8"
2x327 2x1-5/8" 2x7/8"
MODEL 43E
2.- INSTALLATION
2.5.-REFRIGERANT CONNECTIONS
Service
valve
To outdoor
unit piping
To the
indoor unit
Service
port
Copper
cover
Copper tube to
connect with
indoor unit