Daikin Rebel DPS Series Installation And Maintenance Manual page 83

Constant Speed Frost Prevention
When there is a threat of frost on the enthalpy wheel, the wheel
is jogged so that less enthalpy transfer occurs and frosting
of the wheel is avoided. Frosting can occur on the enthalpy
wheel when the exhaust air leaving the wheel is saturated. This
condition occurs when two lines intersect on a psychrometric
chart, and it does not occur when these two lines do not
intersect (see Figure 84).
Variable Speed Frost Prevention
When there is a threat of frost on the enthalpy wheel, the
wheel is slowed down so that less enthalpy transfer occurs
and frosting of the wheel is avoided. Frosting can occur on
the enthalpy wheel when the exhaust air leaving the wheel is
saturated. This condition occurs when two lines intersect on
a psychrometric chart, and it does not occur when these two
lines do not intersect (see Figure
Energy Recovery Exhaust Hoods
Units with the optional energy recovery section have one
or two exhaust hoods (depending on model). Each hood is
shipped in three pieces, consisting of one top and two sides.
Install exhaust hood over the barometric relief dampers by
installing two sides first and then install the top.
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84).
Optional Energy Recovery Wheel
Variable Speed Frequency Control
A variable frequency drive is included with the frost protection
option and it controls the speed of the enthalpy wheel. The
unit has also been programmed for the recommended range
of wheel speed operation. Typical wheel speed is 45 RPM, but
the programming can allow for wheel speeds above or below
45 RPM. Check all factory settings to make sure they are
consistent with the application.
Enthalpy wheel speed will be controlled by exhaust
temperature measurement .
Slide-Out Wheel
The wheel can be pulled out to facilitate cleaning and servicing
(Figure 85). Unplug the control wires before sliding the wheel
out of position .
Figure 85: Slide-Out Energy Recovery Wheel
83 IM 1125-13 • REBEL ROOFTOPS