Connecting Control Signal Cables; Installation Inspection - Liebert PEX+ Series User Manual

24 Chapter 4 Electrical Installation

4.3.2 Connecting Control Signal Cables

Open the sealed panel of the electric control box of condenser to reveal the fan speed controller board, according to
the cable connection instructions in Liebert.PEX Condenser User Manual. The signal cable connection of condenser is
as follows:
Wiring of a condenser with single system used to match an indoor unit with single system
The digital signal of dry contact J6 on the board (see 3.1 Cable terminals in Liebert PEX Condenser User Manual for
the locations) is connected with the control terminals 70#/71# (see Figure 4-3) of the indoor unit.
Wiring of two condensers with single system used to match an indoor unit with dual system
The digital signals of dry contacts J6 on the condenser board corresponding to compressor 1# are connected with the
control terminals 70#/71# of the indoor unit, and the digital signals of dry contacts J6 on the condenser board
corresponding to compressor 2# are connected with the control terminals 70A#/71A# of the indoor unit.
Wiring of a condenser with dual system used to match an indoor unit with dual system
You should short the terminals 70# & 70A# and 71# & 71A#. The digital signal of dry contact J6 on the board can be
connected with the control terminals 70#/71# or 70A#/71A#.For the detailed connection, refer to Appendix 1 Circuit
Diagram.
Connecting Power Cables Of Condenser
The power cables of the outdoor unit are connected with the MCBs reserved in the condenser (see Figure 4-1).

4.4 Installation Inspection

After the electrical installation is completed, you should confirm it according to Table 4-2.
The power supply voltage meets the rated voltage on the unit nameplate
The system electric loop has no open circuit or short circuit
Power cables and ground cables to the MCBs, indoor unit and condenser are
well connected
The ratings of the MCBs and fuses are correct
The control cables are well connected
All the cables connections are fastened, with no loose screws
After confirming the above points, you can start the commissioning. The commissioning is a professional operation
and please contact Emerson engineer to do this job.
Do not power on the unit until Emerson authorized technical has checked and confirmed the unit.
Table 4-2 Installation Inspection
Items
Liebert. PEX+Series Precision Air Conditioner
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