single stage thermostat on CSV060 or a two-stage thermostat on CSV096–300. If equipped, the
factory hot gas bypass option is installed on refrigerant circuit #1.
Two discrete speeds
Indoor fan shall have two discrete speeds. High and Low indoor fan discrete speeds are achieved
by means of VFD. The High speed is available only when both compressor stages are active. The
Low speed (60% of High Speed RPM) is activated only when running single compressor stage, fan
only, or air side economizer.
VFD is factory mounted and wired. Installer is required to field wire fan power wiring between
evaporator and condenser if the unit being shipped factory split. The power wiring can be found
inside the VFD enclosure, no extra power wiring is required—sufficient length is provided. The VFD
option does not include a bypass circuit in case of microdrive failure. Microdrive will need to be
replaced to reactivate unit. In case of VFD failure the evaporator fan will stop running, however
unit compressors will continue to run until a low pressure safety trip is activated.
Refer to separate
VFD for Self-Contained Units Installation and Operation manual (Form 145.13-NO1)
for detailed installation and operation instructions.
Figure 28: VFD controller
43
C-Series Vertical (CSV) Water-Cooled Self-Contained Units, B Generation, R-410A Installation, Operation, and
Maintenance Manual
