Emerson MINI-MATE2 Recommended refrigerant line sizes, Site Preparation and Installation

Site Preparation and Installation

Chilled Water Piping—On chilled water units install manual service shut-off valves at the supply and return lines of each unit. These shut-off valves are used for routine service or emergency isolation of the unit.

Chilled water supply and return lines must be insulated. Insulating them will prevent condensation of the water supply and return lines to the unit.

The minimum recommended water temperature is 42°F (5.5°C). Connection sizes are 1-1/8" (28.6mm) OD copper.

Water/Glycol Piping—Water- and glycol-cooled systems require coolant loop connections as specified in the condensing unit installation instructions.

Refrigerant R-407CPiping—All split systems require two refrigerant lines (an insulated copper suction line and a copper liquid line) between the evaporator and the condensing unit.

! WARNING

Risk of explosive discharge of high pressure refrigerant. Can cause serious injury. Relieve refrigerant system pressure before working with piping/connections.

Two possible methods exist for installing the copper suction and liquid lines.

•Close coupling the units together using the quick connects. (See Figure 15).

•Using an optional sweat adapter kit and hard piping between the two units.

All refrigeration piping should be installed with high temperature brazed joints. Prevailing good refrigeration practices should be employed for piping supports, leak testing, evacuation, dehydration and charging of the refrigeration circuits. The refrigeration piping should be isolated from the building by the use of vibration isolating supports. To prevent tube damage when sealing openings in walls and to reduce vibration transmission, use a soft flexible material to pack around the tubes.

When installing remote condensing units above the evaporator, the suction gas line should be trapped at the evaporator. This trap will retain refrigerant oil in the off cycle. When the unit starts, oil in the trap is carried up the vertical riser and returns to the compressor.

Table 8 Recommended refrigerant line sizes

Equivalent Pipe				Liquid	Suction
Length, ft (m)
50 (15)				1/2"		1-1/8"
100 (30.5)				5/8"		1-1/8"
150 (45.7)				5/8"		1-3/8"
Suction line and liquid line sizing based on < 3 psi pressure drop in each and suction line refrigerant
velocities >1000FPM (5.1m/s) for proper oil return.
Table 9	Equivalent lengths for various pipe fittings, ft (m)
Copper Pipe			90 Degree				90 Degree	45 Degree		Gate	Globe	Angle
OD, in.		Elbow Copper					Elbow Cast	Elbow	Tee	Valve	Valve	Valve
1/2			0.8 (0.24)				1.3 (0.39)	0.4 (0.12)	2.5 (0.76)	0.26 (0.07)	7.0 (2.13)	4.0 (1.21)
5/8			0.9 (0.27)				1.4 (0.42)	0.5 (0.15)	2.5 (0.76)	0.28 (0.08)	9.5 (2.89)	5.0 (1.52)
3/4			1.0 (0.3)				1.5 (0.45)	0.6 (0.18)	2.5 (0.76)	0.3 (0.09)	12.0 (3.65)	6.5 (1.98)
7/8			1.45 (0.44)				1.8 (0.54)	0.8 (0.24)	3.6 (1.09)	0.36 (0.1)	17.2 (5.24)	9.5 (2.89)
1-1/8			1.85 (0.56)				2.2 (0.67)	1.0 (0.3)	4.6 (1.4)	0.48 (0.14)	22.5 (6.85)	12.0 (3.65)
1-3/8			2.4 (0.73)				2.9 (0.88)	1.3 (0.39)	6.4 (1.95)	0.65 (0.19)	32.0 (9.75)	16.0 (4.87)
1-5/8			2.9 (0.88)				3.5 (1.06)	1.6 (0.48)	7.2 (2.19)	0.72 (0.21)	36.0 (10.97)	19.5 (5.94)

Refrigerant trap = Four times equivalent length of pipe per this table

19 Liebert® Mini-Mate2™