Re: Garage Door Opener keypad recommendations

[Jim <alarminex@xxxxxxx>]

On Nov 20, 10:56=A0am, tourman <robercampb...@xxxxxxxxx> wrote:
> On Nov 19, 12:24=A0pm, Jim <alarmi...@xxxxxxx> wrote:
>
>
>
>
>
> > On Nov 17, 7:03=A0pm, JoeRaisin <joeraisin2...@xxxxxxxxx> wrote:
>
> > > On 11/17/2010 5:47 PM, Jim wrote:
>
> > > > On Nov 17, 8:06 am, tourman<robercampb...@xxxxxxxxx> =A0wrote:
> > > >> On Nov 17, 6:21 am, JoeRaisin<joeraisin2...@xxxxxxxxx> =A0wrote:
>
> > > >>> On 11/16/2010 7:57 PM, Christopher Glaeser wrote:
>
> > > >>>>> One of my trades is (was) overhead door installation.
>
> > > >>>> Fair enough. I called the company that installed the garage door=
s in our
> > > >>>> neighborhood. They are among the major garage door compainies in
> > > >>>> northern california. I told him about my experience with a broke=
n
> > > >>>> spring, and asked him if the motor should be able to open the do=
or with
> > > >>>> a broken spring. He said no way. He went on to explain that some
> > > >>>> contractors use 1/3 HP for the heavy doublewides because the spr=
ing does
> > > >>>> all the heavy lifting, but they don't recommend the smaller moto=
rs for
> > > >>>> the heavy doors. However, he said that even the 3/4 HP motors ca=
n't open
> > > >>>> a heavy doublewide with a broken spring.
>
> > > >>>>> Now in addition to a power failure, a battery failure, and a st=
ormy
> > > >>>>> night when
> > > >>>>> you come home.... You're going to throw in a broken spring at t=
hat exact
> > > >>>>> moment.? Talk about entropy. Hell, if all that goes wrong then =
that's
> > > >>>>> some
> > > >>>>> kind of mojo warning you not to go in.
>
> > > >>>> I'm not sure you understand the scenario I'm describing. I'm tal=
king
> > > >>>> about a single point of failure. I know many people (myself incl=
uded)
> > > >>>> who do not carry any house keys. The only way for them to gain e=
ntry to
> > > >>>> their house (without a break in), is through the garage door. If=
 the
> > > >>>> garage spring breaks while they are outside the house, and they =
have a
> > > >>>> heavy garage door, then gaining entry to the house may present a=
 challenge.
>
> > > >>>> Best,
> > > >>>> Christopher
>
> > > >>> Are you saying that you leave the door from the garage to the hou=
se
> > > >>> unlocked?
>
> > > >> RHC: Good question ! This is a very poor idea and an ongoing sourc=
e of
> > > >> false alarms. If the door doesn't close properly and isn't locked,
> > > >> high winds outside can cause enough of a vacuum inside the garage =
to
> > > >> pull or push the door open just enough to trigger the zone (especi=
ally
> > > >> with magnetic contacts versus roller balls behind the door) . This=
 is
> > > >> a common cause of false alarms that I routinely warn my clients ab=
out.-
>
> > > > Ummmm what kind of "roller ball" would you use on an overhead door?
>
> > > > I can see a 2" gap magnetic switch but a roller ball? =A0Well, mayb=
e if
> > > > it was about =A06 inches in diameter to give you the two inches of =
play.
> > > > I think the door would have a hard time trying to push in a ball th=
at
> > > > size and the kids would constanly be leaning their bicycles against
> > > > it. :-)
>
> > > We were talking about the garage to house door.
>
> > > Though a six inch roller ball would be a sight to behold...-
>
> > Oh.
>
> > However. Unless I don't have any other choice I don't use roller ball
> > switches on doors. I think it's been pretty well documented that all
> > it takes is a grain of sand or a paint chip to jam a roller ball
> > switch in the closed position.
>
> RHC: I guess we differ somewhat on that point. I have used thousands
> of roller balls on doors and had less than half a dozen give me any
> type of trouble. And then, it can be as you say...dirt jamming the
> switch, but more often it's some idiot who's painted over the thing,
> disabling it. I've also used thousands of buried magnetic switches
> too, and these give me far more trouble, since they don't have the gap
> "forgiveness" inherent in a roller ball contact. They seem to give
> trouble when 1- the customer forgets to lock the door and the wind
> blows it open enough to trigger the alarm, or 2- when some idiot
> originally installed it at a downward angle, thereby limiting the gap
> length before it triggers.
>
> I guess they both have inherent problems but a quality roller ball is
> IMO no more trouble than a magnetic switch. And as always, it usually
> comes down to improper application or installation.-

What's wrong with that is that a roller ball will fail and you don't
know it. The mag switch fails open.

I'd agree with you on the inherent problems if you're using standard
magnet recessed contacts. But now ..... with the newer Rare Earth
magnets, there's no problem at all with the issues you cited. You just
have to be careful the Rare Earth magnets don't pull the fillings out
of your teeth.