GREENHECK HB Series Industrial Backdraft Dampers User Manual
- June 1, 2024
- GREENHECK
Table of Contents
GREENHECK HB Series Industrial Backdraft Dampers
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.
Receiving and Handling
Upon receiving dampers, check for both obvious and hidden damage. If damage is found, record all necessary information on the bill of lading and file a claim with the final carrier. Check to be sure that all parts of the shipment, including accessories, are accounted for. Dampers must be kept dry and clean. Indoor storage and protection from dirt, dust, and the weather is highly recommended. Do not store at temperatures over 100°F (38°C).
SAFETY WARNING
Improper installation, adjustment, alteration, service or maintenance can
cause property damage, injury or death. Read the installation, operating, and
maintenance instructions thoroughly before installing or servicing this
equipment. This manual is the property of the owner and is required for
future maintenance. Please leave it with the owner when the job is complete.
General Instructions
The following instructions should be followed when trying to adjust counterbalance weights on HB and HBR series dampers. This is not intended to be used for modification for use as a pressure relief damper. The HB and HBR series backdraft dampers are adjusted for the specified flow direction at the factory. The external counterbalance is adjusted for “easy operation”. These instructions address adjustment of the blade counterbalance for the following:
- Damper mounting orientation and/or flow direction has changed in the field
- The damper requires excessive start-open pressure or does not close
- The blade seal has been removed from the field
- Counterbalance settings have been erroneously “adjusted” in the field
Single-section wide dampers will have the external blade counterbalance on one (linkage) side of the damper. Dampers with two sections will have a linkage on both sides of the damper assembly. Arms are usually mounted on every other axle, starting at the bottom, until the magnitude of the counterbalance requires arms on every axle. The steel airfoil models, HB-230 and HB-330, will require more counterbalance weights than model HB-120 with single-thickness blades or models HB-110 and HB-240 with aluminium blades. The longer arms are angled so they will nest when installed on every axle. Greenheck’s policy is to distribute counterbalance weights evenly among the blades to minimize linkage loading and to improve blade closure.
Standard Components
Counterbalance Adjustment
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Adjust the FULL OPEN blade stop first. On most models, a bolt with a spacer is used through the top linkage clevis arm. Open and close the damper to verify there is no interference between the axles and the nested counterweight arm.
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Place the damper in the installed mounting position and flow direction.
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Adjust blade counterbalance at full open position first. The fan (flow) must not be operating. Rotate the damper blades to open. The crankarms or counterweight arms are generally 180° from the damper blade centerline. On very small dampers with aluminium blades, the crankarm may be inclined towards the damper outlet, due to the torque of the linkage. Adjust the counterweight plate centre distance until the blades start to clothe se from the fully open position. Moving plate(s) out will increase counterbalance. It may be necessary to add or delete a plate. Counterweight plate quantity per arm should not vary more than 1 ⁄2 inch among the counterweight arms.
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Close the damper. Blades should close completely (you can feel the blade edge seals make contact) without slamming.
Note: Counterweight arms are welded to the axles as shipped. Arm adjustment will require the weld to be removed and to be re-welded after modification.- If closing too hard, loosen the arm fastener to the axle and rotate the top of the arm towards the upstream of air entering the side. Retighten the fastener.
- If not closing, loosen the arm fastener to the axle and rotate the top of the arm downstream or discharge. Retighten the fastener.
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Open the damper and recheck the full open operation. Readjust per step 3 if necessary. Recheck the full closed position (step 4) as any modification at one position has a slight impact on the other.
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Tighten all counterweight and arm fasteners securely.
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Test damper closure by opening the damper blades and releasing from 1 ⁄4, 1 ⁄2, 3 ⁄4, and full open position.
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The damper should close from all positions without assistance.
Damper Maintenance
Greenheck’s dampers are designed to be trouble-free and hassle-free under normal operation. Dampers are to be installed square and straight to prevent binding during operation. The following annual damper maintenance suggestions will help to ensure proper damper operation and increase the life expectancy of the damper.
Foreign Matter
Over the course of time, dirt and grime may collect on damper surfaces. The
damper surfaces should be cleaned to prevent hindrance to airflow.
Moving Parts
Make sure that parts such as linkage, bearings, blades, etc. that are
intended to move freely, can do so. Lubricating these components can prevent
possible rusting and unnecessary friction increase. Use only a moli-spray oil
or similar graphite-based oil as regular lubricating oil will attract dirt.
Bearings
Plastic and press-fit ball bearings (without grease fittings) do not require lubrication. Ball bearings with grease fitting gs should be lubricated as follows:
Closure
Remove foreign materials that may be interfering with blade closure or
effective sealing of the blades with each other or with the frame. Inspect
blade seals yearly and replace them as necessary.
Operation
While operating the damper through its full cycle, check to see that the
blades open and close properly. If there is a problem, check for loose
linkage.
Our Commitment
As a result of our commitment to continuous improvement, Greenheck reserves
the right to change specifications without notice. Product warranties can be
found online at Greenheck.com, either on the specific product page or in the
literature section of the website at
Greenheck.com/Resources/Library/Literature.
Phone: 715.359.6171
Fax: 715.355.2399
Parts: 800.355.5354
E-mail: gfcinfo@greenheck.com
Website: www.greenheck.com