Installation Notes Of Connector; Required Pipe Connections; Connecting Refrigerant Pipe - Liebert DM Series User Manual

12 Chapter 2 Mechanical Installation
5. The equivalent length of each part is given in Table 2-4. The resistance loss caused by elbows and valves has
been taken into consideration. The installer should confirm if these values are appropriate for site conditions.
Liquid pipe OD (inch)
3/8
1/2
5/8
3/4
7/8
1-1/8

2.6.2 Installation Notes Of Connector

Be careful when connecting the quick thread connector. Read through the following steps before making connection.
1. Remove the dust-proof caps.
2. Carefully wipe coupling seats and threaded surface with a clean cloth.
3. Lubricate the male thread with refrigerant oil.
4. Thread the coupling halves together by hand to ensure that the threads mate properly.
5. Tighten the coupling body's hexagon nut and union valve until a definite resistance is felt.
6. Use a marking pen to draw a line lengthwise from the coupling union nut to the bulkhead. Tighten the nuts an
additional quarter turn with two wrenches. The misalignment of the lines shows how much the coupling has been
tightened. The final quarter turn is necessary to ensure that the joint does not leak. Two wrenches must be used to
cooperate with each other during connection, because one wrench can damage the coupling copper lines easily.
The recommended torque values are listed in Table 2-5.

2.6.3 Required Pipe Connections

Refer to Figure 2-2, the required pipe connections are as follows:
 Refrigerant pipe between the indoor unit and the outdoor unit (discharge pipe and liquid pipe).
 Drain pipe of the indoor unit.
The following pipe connection is required if a humidifier is selected.
 Water supply pipe to the humidifier.

Note
Before starting-up, ensure that all pipe connections have been completed without leakage after engineering installation.

2.6.4 Connecting Refrigerant Pipe

Piping notes
1. The copper pipes provided by the factory are 5m (see Table 2-1). If longer pipes are required, contact Emerson or
your sale agency.
2. The liquid pipe is the refrigerant liquid pipe of the outdoor unit outlet. So a reasonable pipe diameter and length
should be selected for the liquid pipe to ensure that the pressure drop of the refrigerant liquid through the pipe during
unit operation does not exceed 40kPa (5psi ~ 6psi).
3. The pipe should be installed and removed with care so that they will not get kinked or damaged. Use tube benders
and make all bends before making connections to either end.
Table 2-4 Equivalent length of each part
90° elbow
0.21
0.24
0.27
0.3
0.44
0.56
Table 2-5 Recommended torque value
Coupling size
5/8"
3/4", 7/8"
New Liebert_DM Series Air Conditioner User Manual
Equivalent length (m)
45° elbow
0.10
0.12
0.15
0.18
0.24
0.3
Torque value (N . m)
7 ~ 8
25 ~ 32
T-type three way
0.76
0.76
0.76
0.76
1.1
1.4