Autoquip FREIGHTLIFT FL4M - Manual (Page 72)

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7. Once confirmed that all slack chain sensing switches shut the motor off as required,
chain tension must be re-established in all lifting chains. Because the slack chain
sensing switches are now set properly, the motor will not run to lift the chains.
Therefore, a qualified electrician must install a temporary wire jumper inside the lift’s
motor control panel and bypass the slack chain sensing switches in order to be able
to run the motor and raise the carriage enough to re-establish chain tension. Refer
to the job-specific electrical schematic for identification of the correct electrical
contacts to accomplish this.
NOTE: Make sure to remove the temporary jumper once the sensors are adjusted
properly and after chain tension is re-established in both lifting chains.
DRIVE CHAINS (Fig. 38c)
8. To set these pre-mounted slack chain sensing switches mounted to the drive base,
first gain a safe access to the top of the masts. There is a slack chain sensing
switch required for each drive chain, (4) total – (2) mounted above the chain loop,
(2) mounted below the chain loop. All switches are to be wired normal open – held
closed.
9. Make sure that the tensioner roller is aligned with the installed drive chain. Loosen
the bolts holding the Tensioner/Sensing Switch mounting plate to the Unistrut
channels and slide left or right to gain alignment. Re-tighten bolts when aligned.
10. Now make sure that the tensioner arm is pre-loaded by loosening the bolts holding
the Tensioner mounting plate and sliding the plate up or down the Unistrut channels
until tensioner wheel makes contact with the chain. Keep pushing tensioner roller
into the taut chain until the spring-loaded tensioner arm rotates 15- 20 degrees.
Re-tighten bolts when pre-loading the tensioner is complete.
11. Next, loosen the bolts holding the Sensing Switch mounting plate to its Unistrut
channels and slide switch assembly away from the tensioner arm to begin
adjustment. Once clear of the tensioner arm, reverse motion and push the Sensing
Switch back against the Tensioner arm (the two mounted below the drive chain loop
will slide up from beneath, the two mounted on top of the drive chain loop will slide
down from above) until the switch contacts close (listen for the “click”). Re-tighten
bolts now that the Sensing Switch is set.
12. Repeat step 2 on the other drive chain sensing switch assemblies.
INSTALLATION INSTRUCTIONS