Liftmaster 8500/3900 question

[fifth]

Looking to purchase the 3900 series as this is for the shop. I don't need car remotes or safety eye blames... but I am wondering about the security lock at the 8500 comes with.

Without the lock how easy is the door to pull open by had with only the opener holding it closed? Same as a normal, overhead opener??

Thanks

 

[old__man]

Looking to purchase the 3900 series as this is for the shop. I don't need car remotes or safety eye blames... but I am wondering about the security lock at the 8500 comes with.

Without the lock how easy is the door to pull open by had with only the opener holding it closed? Same as a normal, overhead opener??

Thanks

Depends how heavy the door is because that's all that is holding it down.

 

[ROCKNMUD]

If the lock was not used and someone opened the door by hand without pulling the disconnect on the opener. The cables would come off the drum, even if they could only lift it a foot.That would be a big problem. Always install the lock.

 

[Iroc-Z]

My opinion is do it right and put the lock and sensors in

 

[Hot Rod Grampa]

As stated above, the opener is keeping the shaft from turning. Door has no lock. Yes it will open and cables will come off. You paid for the parts, use them. Safety beams are not a joke. Please use them also as intended.

 

[justinthurn]

I just installed an 8900 today. The opener prevents the drum from turning when you lift the door. Without the drum turning, you would have to lift the entire weight of the door. Unless they are using a forklift, no one is going to open the door and steal your stuff. That being said, the kit comes with the deadbolt, you should use it!

 

[turbofreak403]

I just installed 3 8500s.
My doors are 10x10 insulated. I can not pick them up with out the safety removed. But it still seems possible.

The deadbolts are awesome and well worth installing.

 

[NitroShark]

Without the lock how easy is the door to pull open by had with only the opener holding it closed? Same as a normal, overhead opener??

Thanks

I have three LiftMaster 8500s. The lock has two modes automatic and manual. If you switch it to manual and release the safety catch you can easily lift the door if it was balanced properly previously.

 

[bjcouche]

Let me clarify and answer all your questions.
I own both a 3800 and 3900 openers.

A: The 3900 does NOT come with a deadbolt in the box, for those who dont know.

B: On the 3800,3900,8500... If you lift the door manually without pulling the release handle, the opener holds the torsion shaft from turning. To open the door you will have to lift the entire weight of the door. Depending on the size and constriction of your door this could be between 100-1,000lbs. If you did lift it your cables will come off your drums and need to be reinstalled.

C: The 3900 comes with photo eyes in the box and will NOT work without installing them.

D: The 3900 is just a rebadged 3800 with less optional parts in the cardboard box. I bought the 3900, and then bought the "optional" door lock and installed it. The door lock comes standard in the box with the 3800 and optional with the 3900. IF you have the 3900 and want a fancy wall push button, car remotes, overhead light, etc. you can buy those separate as well.

E: If you don't need whiz bang features, don't get them, just more tings to fail. I have the 3800 and 3900 on adjacent doors on my shop, about 3 years old. Three times in a month I go out to the shop to find my 3800 door is wide open... Problem turned out to be a faulty fancy wall pushbutton panel.. To solve the problem I simply installed a dumb (doorbell style) pushbutton on the 3800, just like the 3900 had.

F: I believe but am not certain the 8500 might be slightly different in regards to the wall push button panel. I think that the 8500 uses a different pushbutton panel and the car remotes can only be programmed from that panel. On the 3800 and 3900 you can program the car remotes by using buttons on the opener itself. Also, I've read on this forum lots of people have failures of the 8500 wall button panels... and they cannot just use a doorbell like on the 3800 / 3900...

Brian