Greenheck HPR Series Installation, Operation And Maintenance Manual

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Installation, Operation and Maintenance Manual
Please read and save these instructions for future reference. Read carefully before attempting to assemble, install,
operate or maintain the product described. Protect yourself and others by observing all safety information. Failure
to comply with these instructions will result in voiding of the product warranty and may result in personal injury
and/or property damage.
Instructions
The following instructions should be followed when
attempting to modify HPR series pressure relief
dampers for different damper orientations or
start-to-open pressures. Dampers shipped are set for
the specified start open pressure and flow direction.
Pressure relief dampers designed for horizontal flow
(vertical mounting) are equipped with two sets of arms
(see Figure 1). The pressure set is in the direction
opposite the blades and offset, or balance, the weight
of the blades. The counterbalance is always positioned
horizontally when the damper is closed (approximately
vertical with blades open) and hold the blades closed
until the start-open pressure is reached. Pressure relief
dampers with vertical up flow/relief (see Figure 2) and
vertical down flow (see Figure 3) only have one set of
arms, as the weight of the edge pivoted blades is either
added or subtracted from the weight necessary to hold
blades closed.
Damper will respond to a positive differential pressure in
the direction of blade opening.
Three different crankarms any be used, depending on
the damper size and magnitude of start open pressure.
(see Figure 4).
The blades of this type of damper exhibit a gradual "lift
off" as start-open pressure is reached. The operating
point is not sharply defined, as when a door suddenly
opens. There is a wide flow range where pressure is
approximately constant.
Counterweight Set Procedure (Horizontal
Flow Only)
The counterbalance weights on a vertically mounted
damper (horizontal flow), must be adjusted first, if
the airflow direction is changed. This is covered by a
separate procedure. Basically, the damper is adjusted
for easy operation (blade weight is just counterbalanced)
before the pressure set arms and weights are added.
Pressure Setting Procedure
Position the damper in the proper orientation and flow
direction. If a specific relief pressure is required, install a
U-tube manometer or other pressure measuring device
in the duct work to monitor the static pressure.
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Instructions For Adjusting Pressure Relief Dampers
If the damper flow direction must be changed in the
field, loosen fastener in pressure set crankarm and
rotate arms to correct position. See Figures 1, 2, and
3 for correct pressure set arm orientation with damper
blades closed.
Start-open pressure is adjusted by either changing
weight center distance from axle center line, or by
increasing or decreasing the quantity of plates mounted
to the arms. In extreme cases, the arm length and
quantity must be changed. See table at the end of the
procedure for replacement parts.
FLOW
Figure 1 Horizontal Flow
FLOW
Figure 2 Vertical Up Flow
DAMPER BLADE
Figure 3 Vertical Down Flow
Document 469134
HPR Series
COUNTERBALANCE
PRESSURE SET
DAMPER BLADE
DAMPER BLADE
FLOW
HPR Series 1