gForce Ultra IOM
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Important Refrigeration Components
Variable Speed Compressor (VSC) Features
As the leader in variable capacity compressor technology in the data center industry responding to
environmental and energy challenges, Data Aire developed the gForce Ultra variable capacity
compressor CRAC unit. The quest for greater energy efficiency is continuous; efficiency benchmarks
are always moving up. That’s why Data Aire has moved toward variable capacity compressor
technology for quieter, more energy-saving performance. The compressor technology uses a brushless
Interior Permanent Magnet (IPM) design to provide higher efficiency. It delivers efficiency across a
wider range. A cooling solution optimized for energy consumption and for power grid requirements.
Thanks to a 4:1 modulation ratio, the gForce Ultra can cycle from 25 to 100 RPS to provide greater
savings.
Conventional compressors are designed to run at fixed speed to handle a given capacity requirement.
But in data center applications, the capacity requirement varies. In these situations, a fixed speed
compressor uses various capacity-regulation techniques and can be less efficient than a compressor
utilizing variable capacity technology. A variable speed compressor, on the other hand, saves energy
and operates more quietly by varying speed to match the workload. Tests with VSC compressors have
shown an immediate energy savings and sound level reductions.
Match exactly your cooling requirements to control temperature and humidity, critical for the best
process as well as product quality.
Oil Management
Insufficient oil level can be the result of oil depositing itself in pipes and heat exchangers. The oil deposit
can be returned to the crankcase by increasing velocity for short periods, at regular time intervals or
when the velocity is too low to ensure adequate oil return.
With oil return management functions that are built into the control system, these two oil return
mechanisms can be programmed in the variable frequency drive (VFD) ).
With the oil return management function enabled, the VFD performs oil return by boosting the com-
pressor speed to an appropriate RPM for a selectable duration as programmed into the VFD
parameters. This boost is performed at programmable fixed time intervals or if the compressor speed
has been less than 3000 RPM (50 RPS) for too long which is again a programmable parameter,
whichever comes first. Therefore the maximum time between two consecutive oil return boosts is fully
programmable.
Crankcase Heaters
A crankcase heater will minimize refrigerant migration caused by the large temperature gradient be-
tween the compressor and the remainder of the systems. When the compressor is idle, the oil
temperature in the sump of the compressor must be maintained at no lower than the 10⁰ F (-12.2C)
above the saturation temperature of the refrigerant on the low-pressure side. This ensures that liquid
refrigerant is not accumulating in the sump.
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