Vertiv Liebert PDX, User Manual

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2 Liebert
®
PDX, EconoPhase Version - UM - 265133 - 29.08.2019
1.2 - Liebert
®
PDX EconoPhase version
The Liebert
®
PDX is a full- featured precision air conditioner
intended for data centers, network closets, technological
rooms (laboratories, metrological rooms, museums), new and
existing constructions, raised and non- raised floors, moderate
to high density heat loads, also in combination with cold aisle
containments (up to 10 kW/Rack). It provides all the necessary
functions of a standard precision air conditioner, including
cooling, heating, humidification, dehumidification, air filtration,
condensate management, temperature control, alarm functions
and data communications. Thanks to Copeland’s Digital Scroll and
electronic expansion valve availability, Liebert
®
PDX can achieve
a continuous spectrum of capacity output, ensuring a very tight and
precise control on room temperature. Liebert
®
PDX can rapidly
change from one capacity duty to another. Therefore it controls
environmental parameters even working with swiftly changing heat
loads. In Digital Scroll Cooling system depending on the unit size
the modulating capacity range is between 15% and 100% of the
nominal capacity. The compressor can drop down to 10%, but the
system will decrease in efficiency.
Thanks to the capacity modulation we can reduce the starting
and stopping of the compressor which uses a lot of power and
puts a great amount of stress on the components; therefore we
can enhance efficiency and life of the system. With the Liebert
®
PDX
range we are able to manage unexpected very high ambient
temperatures, maintaining the system active, reducing HP alarm
and troublesome stops of the unit. In fact, when the discharge
pressure reaches the limit value, the compressor capacity is limited
to a fraction of the actual request, in this way restricting the heat
rejection and allowing the system running without interruptions.
If, after a defined time, the condensing pressure comes back
within the limit, the capacity will be modulated in the usual way.
Reliability of the Liebert
®
PDX is also maximized, thanks to the
fewer system parts and simple electronic controls which reduces
the unit maintenance.
Digital Scroll motor runs at a constant speed throughout the
operating range.
This unique feature increases the applicability of the
Liebert
®
PDX units into technological rooms, as it eliminates the need
for expensive electromagnetic suppression electronics require
to ensure electromagnetic compatibility. The Digital function
maintains the maximum refrigerant velocity through the pipes. As a
result of these reasons, Liebert
®
PDX units do not need oil return
components. Liebert
®
PDX is designed on modular concept.
The
Liebert
®
PDX
is supplied as a single unit (height 1970 mm),
where coil and fan sections are connected. The units are available
Downflow Up
Downflow Down