The Chain drive sliding gate operator is an automatic sliding gate opener that is used when a rack drive is unsuitable due to installation conditions of the gate system.
For example, if a sliding gate is painted black and faces west, during the day and particularly during the summer months, it will bend significantly due to being heated by the sun on one side of the gate and not the other. This bending or bowing of the gate, particularly if the gates are long, can actually cause the rack to come off the drive pinion wheel of the gate operator.
Other problems sometimes encountered, are where the track is uneven, due to ground movement. This can cause the wheels to bump up and down, and the rack to skip teeth, meaning either that the limits are put out of adjustment or damage to the rack.
These problems can be solved easily by using the Chain Drive option. A chain drive operator will pull the gate open and shut via the chain fixed to each end of the gate, and run through 2 idler sprockets and a drive sprocket. It is also safer for gates on a slope, where, if a rack drive was used and there is any misalignment, the gate could potentially ‘run away’ down hill causing a significant safety risk.
Chain drive operators are easy to install. They can be built with internal limits or with a SEW PLC control system. The unit is easily fixed in position by bolting the mounting plate down with 4 x M12 masonry anchor bolts. Chain supports are then fitted every 1000mm along the bottom rail of the gate. The provided chain brackets are then bolted to either end of the gate and the chain is fitted to these brackets.
The main maintenance required is oiling of the chain every 3 months to minimise wear and tear. Some people think that chains can stretch over time. This is a myth. What can actually occur is wear and tear on each chain link, of only a fraction of a millimetre. However, over the length of the chain, for instance if a gate was quite long, say 12 metres, this can cause slight slackness in the chain. It is easily avoided by regular oiling of the chain. Also, the brackets which fasten the chain to the gate are adjustable.
The chain drive operator is available in two variations. The first model (GDS 630 Li CH) has a .75Kw inverter, and a .75Kw drive motor. This will drive a gate in speeds up to 630mm per second on opening with variable ramp up, ramp down times. This is suited to overhead track gates, or tracks which are not level or straight.
The second model (GDS 630 Li Ch HD) has a 1.5Kw inverter and a 1.1Kw drive motor. This is suited for very heavy gates as well as gates on slopes.
Chain and spacers are a separate purchase item, because it depends on the length of the gate as to how much is supplied. Also, some purchasers prefer to buy stainless steel chain.