Greenheck EM Series (468391) - Manual (Page 3)

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remain in the full open position then adjustment #2 is
required.
If the airflow through the damper is light and the blades
only slightly move from the closed position, then adjustment
#1 is required.
Adjustment #1:
Moving the weight stack along the length of the
mounting bracket slot will effect the full closed balance
of the blade assembly. Moving the weights closer to
the blade pivot point will cause the blades to become
less balanced so that at some point, the blades would
fall open. Care must be taken to ensure that when the
weights are moved outward from the blade pivot point
the weights will not interfere with the adjacent blade
when the blades close. Moving the weights away from
the blade pivot point will force the blades to close
properly. Care must be taken to ensure that when the
weights are moved outward from the blade pivot point
the weights will not interfere with the adjacent blade
when the blades close. Performing adjustment #1
will have a small effect on adjustment #2 therefore, if
adjustment #2 is critical, then adjustment #2 may need
to be repeated.
Adjustment #2:
The damper is factory assembled with the
counterbalance weights and bracket installed such
that, when the blades are closed, the counterbalance
weights and bracket are
positioned directly inline or
slightly ahead of the blade
pivot points. The position
of the weights will provide
a slight load that will cause
the blades to rotate from the
full open position toward the
closed position. To increase
this load, the counterweight-
mounting brackets can be
bent toward the adjacent blade surface. Bending
the counterweight mounting brackets will move the
counterweight stack which will force the blades to
start closing. This adjustment should be performed in
small increments to each weight bracket since bending
the brackets two much will cause the weight stack to
interfere with the adjacent blade surface. Performing
adjustment #2 will have a small effect on adjustment #1
therefore, if adjustment #1 is critical, then adjustment
#1 may need to be repeated.
increased or both adjustments may need to be addressed.
Adjustment #1:
Moving the weight stack along the length of the
mounting bracket slot will effect the full closed balance
of the blade assembly. Moving the weights further
away from the blade pivot point will cause the blades
to become more balanced so that at some point, and
with enough weight, the blades would remain open
without air pressure being applied. Care must be taken
to ensure that when the weights are moved away from
the blade pivot point the weights will not interfere with
the adjacent blade when the blades close. Moving some
of the weights back towards the blade pivot point will
allow the blades to return to the closed position.
Adjustment #2:
The damper is factory assembled with the
counterbalance assembly installed such that, the
counterbalance weights and bracket are positioned at
a slight angle to the surface
of the blade. This angle will
position the weights such
that they will provide a slight
load that will cause the blades
to rotate from the full open
position toward the closed
position. If for some reason
the blades remain in the open
position then you will need to
increase this load. To do this
the counterweight-mounting
brackets should be bent further away from the blade
surface. Bending the counterweight mounting brackets
will move the counterweight stack away from the blade
surface and therefore the torsion effect will force the
blades to start closing. This adjustment should be
performed in small increments to each weight bracket.
Performing adjustment #2 will have a small effect on
adjustment #1 therefore, if adjustment #1 is critical,
then adjustment #1 may need to be repeated.
Counterbalance Adjustment for EM/ES-40, 41 &
42: Horizontal Mount – Vertical Airflow Down
Adjustment #1 will effect the balance of the blades in the
closed position. Adjustment #2 will effect the balance of the
blades in the open position along with a small change to
the balance in the closed position.
If the damper blades are only opening partially under airflow
and you want them to open further or all the way, then
adjustment #1 will need to be performed. If the damper
blades do not close completely and adjustment #1 has
been addressed, then more weight is required. If the blades
Bend Here
Bend Here