Mammoth 800 to 5500 CFM: Dedicated Outdoor Air System with Enthalpy Wheels (VHC) - Manual (Page 19)

MAMM-VHC-IOM-1A (JANUARY 2013) 19
Perimeter Seal Replacement
To replace the perimeter seal, the enthalpy wheel must be
removed from the frame. Disconnect the service connector
to the drive motor of the enthalpy wheel cassette. Remove
the cassette from the unit and stand the assembly on the
floor or roof. Remove the dust cap (#1, Figure 8) from the
bearing on the drive motor side of the cassette. Remove
the bolt (#2, Figure 8) from the end of the wheel shaft with
a socket or wrench on the drive motor side. Repeat this
procedure for the other side of the cassette assembly. Re-
move the four bolts (#3, Figure 8) with a socket or wrench.
Remove the beam and bearing assembly from the end of
the wheel shaft. Loosen the four Nyloc nuts (#1, Figure 9)
holding the drive motor using a socket or wrench. Rotate
the drive motor in the slots to loosen the drive belt and
remove the belt. Lift the enthalpy wheel out of the frame
with assistance and set aside. Remove the perimeter seal
halves (#4, Figure 8) from the cassette frame assembly.
Install the two new perimeter seal halves by pressing them
into place, cutting to the correct length as is necessary. The
perimeter seals are non-adjustable. Complete the installa-
tion by reversing the above procedure.
Face Seal Replacement and Adjustment
To replace the face seals, the cassette assembly must be
removed from the unit. Disconnect the service connector
to the drive motor of the enthalpy wheel cassette. Remove
the cassette from the unit and stand the assembly up on
the floor or roof. Remove the screws holding the face seals
(#5, Figure 8). Replace the two seals (supply and exhaust
sides), cutting to length as required. Adjust the seals in the
slots so that the brush just touches the face of the wheel.
Complete the installation by reversing the above proce-
dure.
Enthalpy Wheel Drive Belt Replacement
and Tensioning Adjustment
The enthalpy wheel drive belt can be tightened by slid-
ing the cassette assembly only part way out of the unit.
Disconnect the service connector to the drive motor of
the enthalpy wheel cassette. Slide the cassette assembly
out of the unit enough to access the drive motor. Loosen
the four Nyloc nuts (#1, Figure 9) holding the drive motor
using a socket or wrench. Rotate the drive motor to loosen
the belt and replace the belt if necessary. Rotate the drive
motor in the slots to tighten the drive belt. Secure the motor
in its new location by tightening the four Nyloc nuts (#1,
Figure 8). Complete the installation by reversing the above
procedure.
Cassette Service
CAUTION
When handling the enthalpy wheel, ensure not to damage
the face of the wheel.
CAUTION
When handling the enthalpy wheel, ensure not to damage
the face of the wheel.
Figure 8: Cassette and drive
Figure 9: Tension adjustment
WARNING
Disconnect the main power switch to the unit before per-
forming service and maintenance procedures.
!
CAUTION
When handling the enthalpy wheel, ensure not to damage
the face of the wheel.