Instruction Manual
64 
proper  operation  efficiency  and  building 
occupant comfort. 
Normal  maintenance  requires  periodic 
inspection  of  filters,  the  cassette  wheel, 
drive belts, air seals, wheel drive motor, and 
its electrical connections. 
Wiring  diagrams  are  provided  with  each 
motor.  When  wired  according  to  wiring 
diagram,  motor  rotates  clockwise  when 
viewed from the shaft/pulley side. 
By  carefully  reviewing  the  information 
within  this  section  and  following  the 
instructions,  the  risk  of  improper  operation 
and/or  component  damage  will  be 
minimized. 
It is important that periodic maintenance be 
performed  to  help  assure  trouble  free 
operation. 
Initial Mechanical Check and Setup 
Outdoor  units  equipped  with  outside  air 
intake will  have an outside  air hood.  The 
outside air hood must be opened prior to unit 
operation. 
Outdoor  air  intake  adjustments  should  be 
made  according to  building ventilation,  or 
local code requirements. 
After the unit installation is complete, open 
the cassette access door and determine that 
the energy wheel rotates freely when turned 
by hand. Apply power and observe that the 
wheel rotates at  approximately  30 RPM.  If 
the wheel  does  not  rotate  when power is 
applied, it may be necessary to readjust the 
“diameter air seals”. 
Air Seal Adjustments 
Pile  type  air  seals  across  both  sides  of  the 
energy wheel diameter  are  factory  adjusted 
to  provide  close  clearance  between  the  air 
seal  and  wheel.  Racking  of  the  unit  or 
cassette during installation, and/or mounting 
of the unit on a non-level support or in other 
than the factory orientation can change seal 
clearances. Tight seals will prevent rotation. 
Cross Section of Air Seal Structure 
Wheel to Air Seal Clearance 
To  check  wheel  to  seal  clearance;  first 
disconnect power to the unit, in some units 
the energy recovery wheel assembly can be 
pulled out  from  the  cabinet  to  view the air 
seals.  On  larger  units,  the  energy  recovery 
wheel may be accessible inside the walk-in 
cabinet. 
A business card or two pieces of paper can 
be used as a  feller gauge, (typically each 
.004”  thick)  by  placing  it  between  the  face 
of the wheel and pile seal. 
Using the paper, determine if a loose slip fit 
exist between the pile seal and wheel when 
the wheel is rotated by hand. 
To adjust air seal clearance, loosen all seal 
plate  retaining  screws  holding  the  separate 
seal  retaining  plates  to  the  bearing  support 
channels  and  slide  the  seals  plates  away 
from  the  wheel.  Using  the  paper  feeler 
gauge, readjust and retighten one seal plate 
at a time to provide slip fit clearance when 
the wheel is rotated by hand. 










