5
Figure 1 - Mounting Remote Condenser Legs
Interconnecting Refrigerant Piping
The chiller and remote condenser ship with a
nitrogen holding charge. Evacuation of this charge is
required before charging with refrigerant. The chiller
is for use only with the air-cooled condenser
provided with the unit. The following section covers
the required piping between the chiller and the
provided air-cooled condenser.
The discharge and liquid lines leaving the chiller
have caps. These line sizes do not necessarily reflect
the actual line sizes required for the piping between
the chiller and the air-cooled condenser.
Refrigerant piping size and piping design have a
significant impact on system performance and
reliability. All piping should conform to the
applicable local and state codes.
CAUTION: Use refrigerant grade copper tubing ASTM
B280 only and isolate the refrigeration lines from
building structures to prevent transfer of vibration. All
copper tubing must have a pressure rating suitable for
R-407c: tubing that is 3/4” OD or larger must be Type
K rigid tubing. ACR annealed tubing coil may be used
for sizes 5/8” ODS or smaller.
Do not use a saw to remove end caps. This might
allow copper chips to contaminate the system. Use a
tube cutter or heat to remove the caps. When
sweating copper joints it is important to evacuate all
refrigerant present and flow dry nitrogen through
the system. This prevents the formation of toxic
gases, corrosive acids, and scale.
CAUTION: Do not use soft solders. For copper-to-
copper joints use a copper-phosphorus braze alloy
(BCuP per the American Welding Society) with 5%
(BCuP-3) to 15% (BCuP-5) silver content. Only use a
high silver content brazing alloy (BAg per AWS) for
copper-to-brass or copper-to-steel joints such as a
45% (BAg-5) silver content. Only use oxy-acetylene
brazing.
WARNING: The POE oil contained within the
compressor is hygroscopic and has the ability to
absorb water vapor from the atmosphere. Take
necessary steps to prevent an open system from
exposure to the atmosphere for extended periods while
installing the interconnecting refrigerant tubing.
Refrigeration Piping Design
The system is configurable in any of the
arrangements as shown in Figure 2, Figure 3 and
Figure 4. The configuration and its associated
elevation, along with the total distance between the
chiller and the air-cooled condenser are important
factors in determining the liquid line and discharge
line sizes. This will also affect the field refrigerant
charges. Consequently, it is important to adhere to
certain physical limitations to ensure the system
operates as designed.
General design considerations are:
1.
The total distance between the chiller and the
air-cooled condenser must not exceed 200
actual feet or 300 equivalent feet. Keep the
distance as short as possible.
2.
Liquid line risers must not exceed 15 feet in
height from the condenser liquid line
connection.
3.
Discharge line risers cannot exceed an elevation
difference greater than 100 actual feet without a
minimum of 2% efficiency decrease.
4.
To form a proper liquid seal at the condenser,
immediately drop at least 15 inches down from
the liquid outlet before routing the piping to the
chiller. Make the drop leg before any bends or
angles connecting to the remainder of the liquid
connection piping.
Figure 2 – Condenser Located at Chiller Level
