OPW Counterbalance 788 Series Manual

Manual - Loading Arm
April 2011
Equipment: Torsion Balance Type: 790A,B,C
Balance Unit for balancing Loading Arms
Suitable for: Loading Arm Balancing
• Easy, Precise Adjustment
• No special tools required
Specifications
Right-Hand: 790A-0020 (White),
790B-0030 (Yellow), 790C-0050 (Red)
Type
Left-Hand: 790ALH-0025 (Black),
790BLH-0035 (Gray), 790CLH (Orange)
Working
-4°F to 176°F (-20°C to +80°C)
Temperature Range
Installation
Spring Unit Assembly
1. Position balance unit on the bosses at back of swivel joint.
2. Fix balance unit with Bolts and Lock Washers.
3. Attach backside of Link Arm [17] to Spring Arm [15] with Pin [16] and 2 Retaining
4. Remove the 4 Socket Head Screws [18] and take Snubber Block [26] off.
5. Raise loading arm to highest position (as vertical as possible).
6. Attach front side of Link Arm [17] to mounting ears on loading arm with Pin [16] and
7. Check balancing action by pulling down the arm. If adjustment is necessary,
follow adjustment instructions below.
8. Install lock-down unit 788-L, if used, by following 788-L installation instructions.
9. Replace Cover [21] using alignment pins [1] and latches [22].
Adjustment
When to adjust torque
A.To raise loading arm higher or for more lifting action INCREASE torque.
B.To decrease loading arm vertical travel or to slow the rate at which the arm rises,
C. Note: Prior to any disassembly, Spring balance tension should be completely relieved to allow
Torque For more lifting action increase torque. For less lifting action decrease torque.
Place ¾" socket wrench on worm gear hex drive.
To INCREASE torque rotate the worm gear hex drive
counterclockwise (to the left).
Rings [14].
2 Retaining Rings [14].
DECREASE torque.
safe disassembly of level arm.
Worm Gear Hex Drive
PHONE: (800) 547-9393 • (513) 696-1500 • Fax: (800) 245-8536 • (513) 932-9845
2726 Henkle Drive • Lebanon, OH 45036 • www.opw-es.com
790 Series Counterbalance
To DECREASE torque rotate the worm
gear hex drive clockwise (to the right).
Release wrench and test loading arm
lifting action.
Note: Prior to any loading arm
disassembly, spring tension should be
completely relieved.
Tip: Spring coil will be loose in housing
when completely relieved of tension.
NEW: Easy-to-use
Spring Cover Latch