Genie M-4500 Owner's Manual

Genie M-4500 Owner's Manual Manual pdf 24 page image

24TO SHORTEN CHAIN RAIL LENGTH: Loosen chain tension as much as possible. Remove screws from sprocket holder and rail end-stop. Slide chain and all rail parts out of rail from header end. Seerail exploded view, Fig. 55 on p. 25, for disassembly details. Measure and cut off excess rail from header end by 1”increment only. Disassemble connector to expose free ends of chain. Using the same measurement as the excess rail length,remove the same amount off chain links and chain strapsfrom BOTH free ends of the chain (Fig. 53). Using rail end-stop as a guide, mark and drill two 3/16"holes on rail sides for rail end-stop screws. Reassemble two piece connector and slide chain and allrail parts into rail from header end according to originalassembly. Tension chain properly (Fig. 52). Before installing rail overhead, check for proper assemblyand operation by manually moving trolley up and downrail length with trolley connected to chain.Chain LinkChain Strap1”Fig. 53Your preassembled rail comes with the tension adjusted tofactory specifications. There should be no need for furtheradjustment. However, if exposed or subjected to unusuallyharsh operating conditions, the tension may need to bereadjusted during the life of the opener.CHECK PROPERTENSION (FIG. 52): Release trolley from belt or chain, then examine the set-ting of the tension adjustment at the header end of therail. Proper tension is set when the tension nut is tightenedjust enough so that the washer will be spaced approxi-mately 1mm or 3/64" from the stationary rail end-stoparch. If the gap between the washer and the rail end-stop archis too big or too small, the tension needs to be adjusted.ADJUST THE TENSION: To increase the tension and tighten the belt or chain, turnthe tension nut clockwise with 7/16” wrench until thewasher is spaced properly from the rail end-stop arch. SeeFig. 52. Once the washer is spaced correctly, any additionaltightening will overtighten the belt or chain and maycause damage to the system. To loosen the tension, turn nut counterclockwise. Reattach trolley.FOR PROFESSIONAL INSTALLERS ONLYIf your particular installation calls for a shorter rail than thestandard length provided, it is possible to shorten the rail.NOTE: Shortening rail too much may result in door travellength reduction and door not opening fully. This dependson door size and configuration. Carefully plan all suchmodifications before proceeding. THIS PROCEDURE SHOULDBE PERFORMED ONLY BY A PROFESSIONAL INSTALLER FULLYFAMILIAR WITH THIS TYPE OF OPENER SYSTEM.TO SHORTEN BELT RAIL LENGTH: Loosen belt tension as much as possible. Remove screws from sprocket holder and rail end-stop. Slide belt and all rail parts out of rail from header end. Seerail exploded view, Fig. 54 on p. 25, for disassembly details. Measure and cut off excess rail from header end. Disassemble connector to expose free ends of belt. Using the same measurement as the excess rail length, cutthe same amount off BOTH free ends of the belt. Using rail end-stop as a guide, mark and drill two 3/16"holes on rail sides for rail end-stop screws. Reassemble belt connector, and slide all rail parts into railfrom header end according to original assembly. Tension belt properly. Before installing rail overhead, check for proper assemblyand operation by manually moving trolley up and downrail length with trolley connected to belt.14. RAIL LENGTH ADJUSTMENT13. TENSION ADJUSTMENTRail End Stop(Header End) TensionNutProper Space (1mm orapproximately 3/64”)Proper Tension AdjustmentWasher Roller Holder AssemblyFig. 52