7.
In the Service menu of the Liebert® iCOM™ controller, select
Diagnostics/Service
>
Diagnostics
:
a.
Enable
Manual Mode.
NOTE: Manual Mode will time out after 30 minutes.
b. In the search box, enter
E177
and press Enter.
Two parameters appear in the Parameter Directory (E177.1 and E177.2).
Press the
Gear
icon in the upper right corner.
Select
Make Writeable
.
Change E177.1 and E177.2 from 15 minutes to 2 minutes.
This reduces the superheat setpoint from 24°F (13.3 °C) to 13°F (7.2°C) in two minutes.
c. In Evaporator Fan options set
Motors
to
On
to operate the fan during Manual Mode.
d. In Compressor Circuit 1 options, set
Compressor Mode
to
Charge
to operate Compressors 1A and 1B at
full capacity. Turn Compressor 1A and 1B to On. The EEV will modulate to control superheat setpoint
e. Reset the charge function as many times as needed to complete unit charging.
NOTE: You must establish and maintain a minimum 20 psig (138 kPa) for the compressor to operate.
f.
Repeat step 7 for Compressor Circuit 2.
8.
Check the refrigerant level in the refrigerant level sight glasses on each receiver after the unit has been
operating for at least 15 minutes.
NOTE: Each receiver at the condenser has two sight glasses and the refrigerant level varies with outside temperature.
9. Adjust the refrigerant level in each circuit to meet the level shown in
Target Refrigerant Level in Sight Glasses
10. After adjusting the refrigerant, allow the system to operate an additional 15 minutes before checking for the
need of further adjustment.
11. Repeat the procedure for the second circuit.
NOTE: A digital scroll compressor can have a clear unit sight glass on the liquid line only when operating at 100%
capacity. When operating with a receiver, the unit sight glass might not become clear even when operating at 100%
capacity. When operating below 100%, the unit sight glass may show bubbles with each 15 second unloading cycle.
Target Refrigerant Level in Sight Glasses at Outdoor Temperatures
•
40°F (4.5°C) and lower—bottom sight glass is 3/4 full
•
40°F (4.5°C) and higher—bottom sight glass is full
If the return air temperature cannot be maintained between 75°F and 85°F (24°C and 29°C) due to lack of load, then the
liquid level receiver must be adjusted to the following if return air is between 65°F and 75°F (18°C and 24°C):
•
40°F (4.5°C) and lower—Charge to the bottom of the top sight glass.
•
40°F (4.5°C) and higher—Top sight glass is 1/4 full.
Vertiv | Liebert® DSE Thermal Management System Installer/User Guide
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