Commissioning; Important Refrigeration Components; Variable Capacity Compressor With Vfd - Data Aire gForce Ultra User Manual

Warning:
the latest edition of ASHRAE Standard 15 and/or any local building, fire or
mechanical codes.
condensers or high pressure relief valve options.

Commissioning

5.7
The system must be monitored after initial startup for a minimum of 60 minutes to
ensure proper operating characteristics such as:
 Proper metering device operation and desired superheat readings
 Suction and discharge pressures are within acceptable levels
 Correct oil level in compressor sump indicating proper oil return
 Low foaming in sight glass and compressor sump temperature 10⁰ F above
saturation temperature to show there is no refrigerant migration taking place
 Acceptable cycling rates of compressors, including duration or run times
Short cycling protection is provided in the VFD. It is factory preset "enabled"
with default parameters. The minimum run time is set to ensure long enough
running time at start up in order to create enough refrigerant flow velocity in the
system to recover the oil to the compressor sump.
 Current draw of compressor within acceptable values
 No abnormal vibration or noise

Important Refrigeration Components

5.8

5.8.1 Variable Capacity Compressor with VFD

The unique feature of the gForce Ultra is the application of variable capacity
compressor. The quest for greater energy efficiency is continuous; efficiency
benchmarks are always moving up. That's why Data Aire is moving toward variable
capacity compressor technology for quieter, more energy-saving performance.
Conventional compressors are designed to run at constant speed to handle a given
capacity requirement. But in data center applications, the capacity requirement varies.
In these situations, a constant speed compressor uses various capacity-regulation
techniques and can be less efficient than a compressor utilizing variable capacity
technology. A variable capacity compressor (VCC), on the other hand, saves energy
10-2014
Pressure relief lines(s) must be vented to the atmosphere per
This applies to all units with either shell and tube
gForce User Manual ● 43