Emerson Copeland 4MF-13X - Compressor Technical Operations; Pressure Controls and Brazing Procedures

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Pressure Safety Controls
High-pressure Control
A high-pressure control with a maximum cut-out setting of 28 bar(g) is required. The high-pressure cut-out should have a manual reset
feature for the highest level of system protection.
Low-Pressure Control
The normal minimum cut-out setting is 0.1 bar(g) for R404A. The low-pressure cut-out should have a manual reset feature for the highest
level of system protection.
Maximum Operating Pressures
Maximum operating pressures according to EN 12693 shown on the compressor nameplate are obligatory and must not be exceeded.
NOTE: The compressor operating range may be restricted for various reasons. Check the application range limitations in
Copeland
®
brand products Selection Software on www.EmersonClimateAsia.com.
Brazing Procedure
IMPORTANT
Blockage! Compressor breakdown! Maintain a ow of oxygen-free nitrogen through the system at very low pressure during
brazing. Nitrogen displaces the air and prevents the formation of copper oxides in the system. If allowed to form, the copper oxide
material can later be swept through the system and block screens such as those protecting capillary tubes, thermal expansion valves,
and accumulator oil return holes.
Contamination or moisture! Bearing failure! Do not remove the plugs until the compressor is set into the unit. This minimizes any
entry of contaminants and moisture.
• The copper-coated steel tubes on Stream compressors can be brazed
in approximately the same manner as any copper tube.
• Recommended brazing materials: any silfos material is recommended,
preferably with a minimum of 5% silver. However, 0% silver is
acceptable.
• Be sure tube tting inner diameter and tube outer diameter are clean
prior to assembly.
• Using a double-tipped torch, apply heat in area 1.
• As the tube approaches brazing temperature, move the torch ame to
area 2.
Figure 8: Suction tube brazing
• Heat area 2 until braze temperature is attained, moving the torch up and down and rotating around the tube as necessary to
heat the tube evenly. Add braze material to the joint while moving the torch around the joint to ow braze material around the
circumference.
• After the braze material ows around the joint, move the torch to heat area 3. This will draw the braze material down into the joint.
The time spent heating area 3 should be minimal.
• As with any brazed joint, overheating may be detrimental to the nal result.
To Disconnect:
Heat joint areas 2 and 3 slowly and uniformly until the braze material softens and the tube can be pulled out of the tting.
To Reconnect:
Recommended brazing materials: Silfos with minimum 5% silver or silver braze used on other compressors.
• High-pressure side (HP): 28.0 bar
• Low-pressure side (LP): 22.5 bar