OM 1077-1 • MAVERICK I 28 www.DaikinApplied.com
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Variable Frequency Drive
This screen shows the information available when a Variable
Frequency Drive (VFD) is connected to the DDC rooftop
unit controller for speed control of the indoor blower. When
this device is not connected, the control will show the word
“UNAVAILABLE” on the second line of the display. The VFD
control is only available on units with a factory-installed
variable frequency drive. To meet ASHRAE 90.1-2010, First
Stage Cool and Fan Only speeds have a default setting
of 50% airflow. Unit air balancing should be performed by
adjusting the blower motor sheave at 100% airflow during
W1, W2, or Y2 call.
Table 16: Variable Frequency Drive
Status
Adjustable Range
Default
UNAVAILABLE / AVAILABLE
*VFD Low Fan Speed – XXX%
50% – 100%
50%
*VFD 1st Stage Cool – XXX%
50% – 100%
50%
VFD Current Speed – XXX%
*Menus that are user adjustable
Status Line
The Status Line shows whether a VFD is available. If this
device is not connected, the control will show the word
“UNAVAILABLE”.
VFD Low Fan Speed
The Low Fan Speed, or “Continuous Fan Speed” is the
percentage of the full speed that the indoor fan is commanded
to run when a “Fan Only” call is given by the building manager
network (if connected) or the room thermostat. The Low Fan
Speed can be adjusted between 50% and 100% of the full fan
speed and has a default of 50% (a 50% reduction in fan speed
is equal to a 50% reduction in airflow).
NOTE:
If the indoor fan is ramping up to speed from a dead
stop, the Low Fan Speed will briefly ramp to 75% of
the full speed in order to “set” the fan proving switch
and confirm proof of indoor airflow.
VFD 1st Stage Cool
This value is the percent of full speed that the indoor fan is
commanded to run an a 1st stage cool call. For two-stage
models equipped with Humidity Control, this is the indoor fan
speed used for a high indoor relative humidity call without an
additional 1st stage cooling call. The 1st stage cooling speed
can be adjusted between 50% and 100% of the full fan speed
and has a default value of 50% (a 50% reduction in fan speed
is equal to a 50% reduction in airflow).
NOTE:
If the indoor fan is ramping up to speed from a dead
stop, the Low Fan Speed will briefly ramp to 75% of
the full speed in order to “set” the fan proving switch
and confirm proof of indoor airflow.
VFD Current Speed
This displays the actual speed of the indoor fan speed as a
percent of full speed.
