In my area, sprinkler system tamper switches are always nippled to a standard 4-square box that simply dangles unsupported. This provides a junction point for the short lengths of wire leaving the tamper switches before being flexed to a nearby point in the fire alarm system. No AHJ has ever had a problem with this installation. I'm curious as to how this situation is handled elsewhere. Are hubbed boxes used as a better means of support by its connection via the nipple to the switch?

Nope.

I've installed all of my F/A systems in exactly the manner described in the original post.

The NEC is oriented towards fire hazards.

The weight of the trivial materials tucked inside such junction boxes is a joke.

If ANYTHING goes awry -- the F/A system goes into ALERT mode -- which is not the same as an alarm.

In ALERT mode the system informs the dispatcher to promptly send out a tech to service the system. The modern, digital, systems will even point out the faulting address.

If, at any time, a bona fide fire / emergency occur, the system will fire off into full ALARM mode -- over-riding the ALERT mode.

EVERY F/A system uses this priority sequence. No system is allowed to fault out -- and fail to notify the dispatcher and those inside the structure.

&&&

You're actually over engineering your scheme... a fault common to electricians the world over.

I always nipple the box to the switch. It isn't what I would describe as "dangle."

FWIW, in Canada we have a rule: "12-3012(2) Boxes and fittings having a volume of less than 1640 ml shall be permitted to be attached to a firmly exposed raceway by threading or other equally substantial means." I always thought a nipple on a tamper switch was firmly secured.

Do you have a similar rule in the NEC?

1) Occasionally, 120v is fed through a tamper switch (even in a modern system). Surely an unsecured, standard box can not be accessible in that scenario.

2) Many AHJ's would not allow an unsecured box for control wiring which is also a low voltage/signal system.

1) Occasionally, 120v is fed through a tamper switch (even in a modern system). Surely an unsecured, standard box can not be accessible in that scenario.

&&&&

I've never seen such a scheme.

Let's narrow this discussion down to just fire alarm systems.

Then the only 120V circuit routinely encountered is a FIRE BELL initiated by the FLOW SWITCH in the F/A MAINS.

Typically, this device trips two parallel, yet independent, switches.

Both are situated on a cam-assembly that rocks/ torques when the flow gets rolling/ or some lever arm.

The 120VAC -- low amperage device -- fires of an 'idiot-simple' fire bell immediately outside the (sprinkler) riser room.

At the same moment, the fire alarm does its thing -- with low voltage logic. (Typ 24VDC to 34VDC -- most set at 28VDC)

The notification appliances receive a reversed polarity -- and are off to the races.

I've NEVER seen the elaborate work-up you are speculating upon here.

As for the 120 VAC bell, there is a special exclusion in the NEC that permits that whip to run in #18 wire. Even after I pointed this out, my field superintendent had me upgrade this whip to #12.

As loud as these bells are, they use practically no current.

They are also a belt & suspenders cure, for the F/A system is making a terrible racket as it is -- as well as notifying the local responders.

&&&&&&&

F/A is not considered control wiring. It's considered a LIFE SAFETY circuit. It even has its own code rules, most of which are entirely outside the NEC, for what it's worth.

triple:

Are you saying the 'box' is connected to a nipple of the flow switch, and that the box has NO other mechanical means of support??

That is correct HotLine1. A standard 4-square held in place by a locknut.

The job I am on right now provided two different outside fire alarm bells to pick from (probably a screw up). One of them was 120v and schematically showed that 120v being switched through the main flow switch. That is the type of box that I DEFINITELY can't imagine not being securely mounted.

In my view, the fact that the fire alarm panel will notify you of an open or short seems like a poor reason to allow an unsecured box. Should we also allow such workmanship for line voltages as long as the item in question is monitored/protected by both gfi and arc fault?

triple...

The TYPICAL flow switch is installed by the sprinkler boys.

It's TYPICALLY inside a robust housing...(red) that's been strapped to the sprinkler mains. (massive systems can have multiple -- and colossal -- pipes; such scale is rarely ever encountered) (Boeing super plant in Everett)

It's from this enclosure that a Greenfield whip is run to some adjacent wall -- typically.

What triple seems to be describing is a set up that has a common 4 square box nippled directly into the (Pott?) box that holds the micro-switches -- using a stubby GRC nipple and some lock-nuts.

Is that right triple?

&&&&&&

While not exactly at the flow switch, I've seen, and installed F/A circuit components in exactly such a manner -- and the AHJ was delighted.

For, there are tamper switches without limit in some schemes. And these tamper switches have SHORT LEADS that HAVE to be landed in a proximate junction box for make-up.

This is compounded by the fact that there is absolutely no way to mount such boxes without running up some insane design and engineering tab. The valves they monitor are clustered all over the critical pipes.

My AHJ was thrilled that I'd even linked them with free-flying EMT. Usually, these connections are made in Greenfield.

In every instance, no strapping is used.

&&&&&

Folks, we're describing controlled spaces that are only ever accessible to techs, electricians, and emergency responders and AHJ.

These spaces are NOT storage spaces, habitable spaces, ... etc. All alien gear is expelled.

There are no field reports of traumas to these schemes.

&&&&&&

Redundant fire bells are quite a 'tell' as they are common as dust when schools are expanded -- with additional sprinklers -- and additional 'sprinkler mains.'

The AHJ is going to insist that each riser get a fire bell. EVERY fireman is trained to expect a riser with each (classic) fire bell.

While the general public is under the impression that such bells are fire bells -- to a fireman they are merely markers for where they must run to TURN OFF THE SPIGOT.

[ Water Bells? ]

During such distress, there is NO TIME to even read big fat door legends such as "FIRE MAIN" "FIRE ROOM" etc.

{{{

Indeed, during such fiascos, the electric power is even at risk.

So the sprinkler boys even have bells that run on water flow itself! (Not so popular these days -- pricy -- and usually design restricted to REALLY hazardous applications.

( Some structures have power trip circuits that will kill all line voltage -- from the outset. This is typical of all high risk assets. (Lumber mills, chemical plants, ...))

}}}

I stopped worrying about big design issues when I was an apprentice. Every over-active electrician that attempted to help out/ get into design ended up being fired/ 'relocated' etc.

This included electricians up to and including a general foreman -- who was a genius, BTW.

It is TABOO to 'correct' the other guys' work.

In the worst possible situations, you'll end up being right. That's how the brilliant general electrical foreman got fired and -- driven out of the industry!

(Not to worry, he made his millions in the stock market and didn't need to work in the first place.)

&&&&

Lastly, offending craftwork is seen all the time.

In which case, take digital pictures and upload them to ECN. Then we all can sound off.

Pictures beat written descriptions of poor workmanship every time!

triple:
Your scenario is best said as 'standard practice'.

What I usually encounter is either flex or EMT (occasional RGC) from the 4 sq to a structure wall and continued to a FA panel.

As Tesla said, there usually is no practical item to mechanically secure the box, other then onto the switch nipple.

IMHO, it is acceptable install.

I know it is standard practice. That was my point. I and everyone I have ever worked with does it exactly that way. A hubbed box (Bell box, weatherproof box) would provide MUCH better support and take no additional work. I am surprised that that isn't the "standard practice".

triple:

My educated guess of bell box vs. 4 sq is in the cost. I agree with you it would look more professional.

Talking about this today with a job foreman, he had an apprentice use a 1/2" 'C' condulet. The foreman was not happy.

This is the same problem as a solenoid with two or three wires hanging out of a nipple. I use a small GUAB14 for those. Maybe everyone - or someone - would be happy with a larger GUAB16 on a tamper switch? They don't even have mounting tabs.

triple...

The last digital address module that I installed at a tamper switch would absolutely NOT fit inside a one-gang Bell box.

Pinched between two steel locknuts on a GRC nipple, 4 square (deep) fill the bill -- and no-one is willing to toss the $$$ at 2-G WP boxes.

BTW, the labor experience across the trade is that a Bell box takes significantly more time to install than a 4 square... It's hubbed, after all.

It will also then demand a WP cover -- with a gasket -- if not then why the Bell box?

Off the cuff, I'd estimate four times the labor burden.

1) Specialty item -- custom order required -- not ordered by the case

2) Orientation -- hubbed -- an issue

3) Starting the hubbed threads onto GRC nipple -- an issue

4) WP gasket -- a pain -- order spares for the inevitable losses

5) 2-G WP go for about 5-10 times the wholesale price of a deep square. Even the distributor doesn't send them out by the case

6) Threading the cover onto a WP is very substantially slower than a 4 square and its flat cover... with its captive screws

7) Greenfield into a hubbed box is a b234523 and slow going... unless you've ordered the connectors that squeeze from the outside down around the Greenfield. These cost more and are typically a custom order because of that fact.

And, at the end of the day, you haven't improved the robustness of the installed system.

The very isolation of these devices in controlled spaces means that there is nothing and no-one to bump into them.

Thirty-year old boxes just sit there and sit there and sit there.

Once these boxes start falling to the ground -- the AHJ will start changing the installation standards.

BTW, you don't even want to THINK about the non-strapping that occurs in Chicago when the residential boys are running EMT. Local standards there take strapping with in 3' as merely a suggestion.

&&&&&&

You best return on intellectual energy is to dope out elegant, clean, installations -- particularly those that are so commonly encountered.

It's a professional calling that will never end.

Looking at other installations helps a lot, either good or bad or terrible.

BTW, each and every time you run across a terrible installation -- photograph it and up load it to ECN.

All of us here abouts love to look at trashy 'work.'

You don't have to put the module in the box at the valve. Just extend the wires over to a wall.

twh...

AHJ will shoot down ANY splices / make up that is not monitored by the F/A logic.

Extending the leads is EXACTLY what's prohibited.

tesla:
There must be some misunderstanding going on.......

IMHO, the thread is regarding fire sprinkler monitoring devices, flow/tamper. The way I understand it, the 'device' is installed & mounted by the sprinkler guys. The +/- 6" conductors exiting said device are to be extended and connected to the FA system. Be it a LV system, a line volt system it don't matter.

A 4sq locknut mounted to the device was and is the original comment.

John...

You've hit the sore spot.

Such extensions of the tamper leads are against the F/A code.

EVERYTHING in the F/A scheme is supposed to be monitored.

No (additional) field splices are to be introduced by the field crew during the installation.

Should they pull out/ fail there would never be any trouble fault recorded in the system.

Which, in regards tampers, is EXACTLY what an arsonist would do.

The ENTIRE purpose of tamper switches is to frustrate professional arsonists - players that know their way around F/A systems.

&&&&&&&

The second you are extending the tamper leads -- you're providing an open shot for an arsonist to gap them open.

After that he'd shut off the valve/ water supply.

Then it's off to the ignition.

When the fire marshall inspects the debris, all that he'd have is an 'innocent' looking gap in the system -- something that the buildings owner could lay off against the original installers.

As you can imagine, the primary employer of arsonists are businessmen.

See: "Who'll Save the Tiger?"

&&&&&&&&

In short -- extending the tamper leads is forbidden.

We use a 4 wire, monitored system on valves. Opening the leads would create a trouble on the system. How are you wiring your tamper switches?

Every tamper I've encountered had more leads than my (digital) (F/A) module was able to address.

For mass production efficiencies, every tamper is wired up like it's headed off to a chemical plant with a SCADA layout.

My memory is getting pretty lame -- but IIRC -- I was landing only a common (typ. black) and N.C. N.O. leads (typ. red, red w/ stripe) ... with the actual switch festooned with at least two complete sets -- if not more -- and redundant grounding and bonding conductors, too. They were a hair-ball far too big for a 1-G Bell box.

My foremen set the policy: the digital address module was to be deployed right at the tamper switch leads. It was a feather weight plastic device with just enough room to accept labeling.

The F/A cabling for such runs was usually a very sloppy Greenfield whip -- typically daisy-chained from one tamper to the next.

It's been long enough that I can't remember exactly what each maker's module required/ monitored. N.C. or N.O. or both.

I've never encountered a single tamper switch wired in the manner described above... but I haven't seen everything.

Tesla:

Am I missing something, or do you get devices with 'leads' that are long enough to reach the FA panel??

Some of us may be talking about different devices.

In every recent (digital) F/A system that I had to install, the manufacturer provided digital address modules that had DIP switches on them to provide a unique digital address.

Typically these addresses were limited to 128 -- per digital loop. ( Though loop is a mis-nomer: the digital systems no longer required loop geometries. Each device in the system was polled -- digitally -- time-sliced -- around the clock to affirm its status.

These modules were required for every tamper switch -- but were quite unnecessary for smoke, heat, etc. detectors. Those items -- also provided by the F/A system manufacturer had integral digital addresses -- DIP switches.

The tamper switches were manufactured and installed by OTHER manufacturers -- not the fellas that engineered the F/A system.

The digital ID modules consisted of a series of contacts -- and associated logic -- such that it could detect and 'translate' trouble faults and alarm conditions back to the main brain -- digitally.

This meant that the F/A panel would read out trouble or alarm "at position 13" -- and also send that info out to the alarm monitoring firm -- thence to the emergency responders.

The tamper switch leads were never longer than ten inches - - typically just eight inches.

The digital modules were flexible enough to interact with ANY F/A (active) element -- with their overwhelming usage being trouble or fault reports.

Actuall alarm conditions were expected to come by way of:

Sprinkler water flow detection
Smoke heads
Heat heads
Duct detectors (for smoke entering forced air circulation)
Pull stations -- the classic device that all school brats loved to pull down.

Tamper switches evolved when it was discovered how many arsonists were shutting off the sprinkler mains before business -- and how many pranksters would fiddle with the mains/ especially at the back flow preventer out near the street.

BTW, fiddling with the various contraptions needed to monitor the position of such massive valves is quite a chore.

After enough fiascos, my employers backed away from F/A installations. (While one went whole hog and set up a separate F/A division.)

It was ultimately realized that journey men make for lousy fire alarm installers. This transition also occurred as the F/A crowd stepped up technical education, standards and certifications. And by such barriers, got their competition to leave the field.

[ It's just as well, you would not believe the lousy installations that some ECs were sticking into service. Top management hadn't a CLUE as to how F/A systems worked -- and how DIFFERENTLY they worked. They are not really an NEC item. They can't cause fires. They are totally oriented towards detecting fires and faults. It really is a different field.]

I guess that the independent verification of every fire alarm installation and modification by a licensed testing company, like we have in Canada, eliminates the problems of lousy installations being stuck into service. They certainly test opening the leads to a tamper switch to make sure it results in a trouble signal.