Dayton Electric Chain Hoist 3YB81

IMPORTANT: Before placing hoist in operation, check the limit switch ad-justment.

Limit switches are provided to protect the hoist against damage resulting from overtravel or to allow setting the hook travel within the factory-set limits of travel.; For easy identification and association with the proper direction of travel, the upper and lower limit switch adjusting nuts are color-coded gold and silver respectively.; Each limit nut has 10 slots for fine adjustment, and the increment of adjustment is such that one slot is equivalent to approximately one link of chain travel.

Movement of the limit switch nuts toward or away from each other increases or decreases the hook travel respectively.; Care should be exercised when adjusting either limit of travel.

ADJUSTING UPPER LIMIT (GOLD NUT)

1. Suspend the hoist. For single chain models raise the load block until there is a minimum clearance of 2" from the hoist housing and the top of the block.; Double chain models require a minimum clearance of 1" from the chain support to the top of the load block.

2. DISCONNECT HOIST FROM POWER SUPPLY and remove the electrical cover.

3. With a screwdriver, pry the spring guide plate out of the slots in the limit switch nuts.

4. Turn the slotted gold nut toward its limit switch until the switch "clicks" then turn two slots farther.; Release the spring guide plate and be sure it slips back into the slots in both limit switch nuts. Do not disturb the silver slotted nut if it has been set previously.

ADJUSTING LOWER LIMIT (SILVER NUT)

DISCONNECT HOIST FROM POWER SUPPLY and move hoist to a work table. Do not remove the electrical cover.

Detach the chain stripper from the bottom of the hoist.

Following the instructions in the section on GEARING, disassemble the transmission assembly.

Remove the output shaft through the transmission, allowing the load sheave and chain guide to be removed from the bottom of the hoist.

Be care not to lose the spacer that is between the load sheave and the bearing on the motor end.

NOTE: Inspect chain guides and load sheave for wear, replace as needed.

Lay the new chain over the load sheave. Allow about 15\ of chain below the hoist on the slack end."

Be sure the welds of the upstanding links are out away from the load sheave and the proper orientation is observed for attachment of the slack end.

Also be sure the load hook assembly (if already attached to the chain) is toward the center of the hoist or to your right looking from the transmission end.

Warning: Use SAE 90 gear oil for lubrication

Sign off on the load chain lubrication

Chain is to be kept clean and lubricated.

Visually check chain every time hoist is used.

Hoist must not be operated when chain is twisted or kinked. An important phase of hoist maintenance is chain inspection. Check individual links and check for chain elongation.

1. Check the chain for overall wear or stretch by selecting an unworn, unstretched length of chain (at the slack end for example).; Let the chain hang vertically with a light load (about 20 pounds) on the chain to pull it taut.; Use a large caliper to measure the outside length of a convenient number of links about 12 inches).; Measure the same number of links in a used section of chain and calculate the percentage increase in length of the worn chain.

2. If the length of the worn chain is more than 1½% longer than the unused chain (0.015" per inch of chain measured), then the chain should be replaced.; If the chain is worn less than 1½%, check it at several more places along its length.

If any section is worn more than 1½%, the chain should be replaced.

The chain used on this hoist has very carefully controlled dimensions and has been heat treated. Do not attempt to substitute other manufacturer's chain.;

Warning: Disconnect hoist from power supply before starting the procedure

Upload a photo of the brake before adjustment

Enter the current gap between the brake armature and the field

Is the gap within the acceptable range (0.015'' - 0.040'')?

If the gap is not within the acceptable range, adjust the 3 locknuts

Is the adjusted gap within the acceptable range (0.015'' - 0.040'')?

Check the clearance at the bottom of the armature

Is the clearance at the bottom of the armature acceptable?