The cost of one vs: two sets of contacts is in my view a minor price difference. There are few installations that require two contacts however, having a spare set of contact is never a bad idea should you need it.
1) You might see an occasion that both contacts are needed, one single pole double throw (normally open/normally closed) connected to a panel (low voltage) the other set connected to bell or some other local alarm that requires line voltage. 2) One set of contacts gets damaged for whatever reason you have the spare to use without having to replace the entire device. If you standardize on two sets of contacts you won't have to run around to get a two switch device requiring Sent from my iPhone > On Nov 25, 2014, at 10:55 AM, Ben Young <[email protected]> wrote: > > So this has been discussed in our office for the past two day or so, and I > wanted to get some more opinions. > > Why is the industry standard (at least in the Mid-Atlantic region) to get > OS&Y tamper switches with two sets of contacts? > > The only time any of our sprinkler installers can remember needing it was > for an old system where they needed the second contact to do some oddball > other system shutdown. > > Our alarm division installers have never wired the second set of contacts > to anything that they can remember. The best guess they could come up with > was if you had a two tenant building with a single feed and both tenants > wanted to monitor the tamper switches. > > And, the second set of contacts costs about $25 more. None of our > suppliers stock the single switch version, so they have to be ordered > direct from the manufacturer. > > Now, this isn't a huge problem since we use butterfly valves wherever > possible, but when you have a fire pump, or a water purveyor who requires > OS&Y valves, you've got to use them. > > The best (worst?) answer that one of the owners here could come up with was > better to have it and not need it, than need it and not have it. > > All the designers and project managers at our company (myself included) > just remember being taught this way... IE, you always order the OSYSU-2, > and that's the way we've always done it. > > I know there's got to be somebody on the sprinkler forums who knows the > reason why this is, or how this came about, right? > > Has anyone else thought about this, or tried to order the single switch > models? > And obviously, this doesn't apply where they're spec required. > > I would love to hear some thoughts on this. > > Thanks, > > Benjamin Young > _______________________________________________ > Sprinklerforum mailing list > [email protected] > http://lists.firesprinkler.org/listinfo.cgi/sprinklerforum-firesprinkler.org _______________________________________________ Sprinklerforum mailing list [email protected] http://lists.firesprinkler.org/listinfo.cgi/sprinklerforum-firesprinkler.org
