Dayton Electric Chain Hoist 3YB91

- Any deficiency causing improper operation

- Any deficiency causing improper operation

Proper lubrication is necessary for a long and relatively trouble-tree hoist operation.; Refer to the following and the RECOMMENDED LUBRICATION SCHEDULE for lubrication points, type of lubricant, and frequency of lubrication.

LOAD CHAIN.; Clean the load chain with acid-free solvent and coat with SAE 90 gear oil. Wipe excess oil to prevent dripping. Never apply grease to the chain.

GEARING.; The gear case of this hoist is filled at assembly with approximately 1½ pints of SAE 90 EP gear oil.; Check oil level by removing the oil level check plug from the side of the hoist. With the hoist hanging level, gear oil should be even with the hole.

BEARINGS. All bearings except hook and idler sheave bearings are lubricated at the factory and should not require additional lubrication. Noisy or worn bearings should be replaced.

LIMIT SWITCH SHAFT.; Remove any dirt accumulation and spray with a general purpose lubricant.

HOOK BEARING.; Apply a few drops of SAE 30 gear or motor oil around the edge of the bearing.

IDLER SHEAVE BEARING (BUSHING).; Disassemble load block and apply a light coat of NLGI #2 grease, or equivalent, inside of bearing.;

Inspect hooks for cracking, extreme wear or spreading

Check if throat openings are spread wider than the maximum permissible 15% increase

Check if any hook is bent or twisted more than 10 degrees from the plane of an unbent hook

Inspect the hook latches to ensure that they close the hook throat opening in a secure manner when a load is applied

Inspect the hook shank and nut for any stripping of the threads or other damage

Check if the hook nut is fully restrained by the retaining pin

Inspect load hooks for cracks by the magnetic particle, dye penetrant or other suitable crack testing inspection method

Sign off on the daily hooks inspection

1. For major repairs or when the hoist is to be sectioned in the suspension area, it will be necessary to move the hoist to a workbench or table.

2. For repairs which can be done by removing the electrical cover only, the hoist need not be moved.

Lowering the hoist to a convenient working level is desirable.

NOTE: If you do not have an experienced mechanic to do your repair work, we recommend that you send your hoist to an approved service station for repairs.; Use authorized repair parts only.

Remove load and disconnect hoist from power supply before starting to do any repairs or to take any sections apart.

The following repair instructions will help you in understanding repair procedures.

1. Remove the electrical cover. The control panel, brake assembly, and limit switch assembly are located under the cover.; The contactor and terminal block are accessible without further disassembly. It will be necessary to remove the electrical panel to replace the transformer, solenoid, limit switches, or brake parts.

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)