Much of my work is the repair or upgrade of alarm systems. I started out building new buildings, and putting in a new fire alarm is fairly easy in comparison for one simple reason: you are in control of the whole process. The equipment is new. It's usually either DOA or reliable. If you took the time and paid attention to doing the job right you don't have many problems. The problems you do have are easier to solve because you know where everything is and how it was installed.
But much of what I do these days are upgrades. If you buy a suite in an existing building and do much remodeling the job will have to permitted, which means that everything in your suite will have to meet current code.
I know some people regard this as a terrible impostion, but inspectors don't get to see buildings once they're built. Lots of things are added one item at a time. An outlet here, a data drop there, they all add up, and such small additions are never inspected. If the work is done sloppily, and sloppy work often takes less time, then ultimately the safety of the building can be compromised. Buy inspecting remodels you get a lot of the crap corrected. Over time the quality of the entire community's building stock improves as older buildings are brought into compliance.
But there are owners of very pretty, well turned out building who think a thing like a fire alarm is nothing but a money sink for no value at all. If it wasn't for codes and insurance they'd never have one.. You don't need live tenants if the building burns down. Now I can understand not wanting to waste money on a bulding. But there is frugal, and there is cheap and the difference is not narrow.
Consider a building i was working in the other day, a nice five story office in a prosperous part of town. The fire alarm system was decent when the building ws built, but calling it out of date would be kind. Electronic systems fail, and if you've done work in the building recently, it's your fault. No matter what the cause they don't believe you.
This building has two notification circuits which power a series of faraday (a brand) horns. A person with normal hearing can hear them if they go off, provided things are quiet. In no way does the install meet current code. They have a ground screw replacing a lug on one of the terminal strips, which wasn't the stock item and one horn/strobe circuit is down on polling voltage as it also controls a relay for the door holders. The panel is old enough that one expects the vintage capacitors to start having problems.
So we told the owner he needed a zone expander, becuase two zones just wasn't going to cut it for a five story building. An expander adds four more zones, and when you do your
inspection all the devices in the building are expected to work just fine. I'm sure the sytem worked when installed but as remodels have occurred more devices have been added. You can get away with adding devicest for a while, but sooner or lader the panel doesn't put out enough juice. Pity the installer who finds out about the voltage drop the hard way. So we finally talked him into an expander, which will also solve his problems for the next half dozen remodels.
So the next step for me was to find the End of LIne Resistor (EOLR) for one of the Horn circuits. Most horn/strobe circutis are wired class B. That means that a DC current is sent out on positive (+) and negative (-) wires that land on the first device. A diffferent set is landed on that first device and from there to the next device. until you get to the last device where an End of Line Resistor spans the positive and negative wires. The wires must be broken at every device and must land on the device. You can't tap or pigtail the wires, so that if a wire comes loose the circuit will open.
That allows the fire alarm panel to monitor the circuit. If the panel sees a resistor of the appropriate rating, the circuit is good. If a wire comes lose somewhere the panel will lose the resistor and sound a trouble, which tells the building maintenance that something in the fire alarm needs fixed. If the circuit opens somewhere in a class B circut every device after the opening will not operate. Which means people might not know about a fire.
So I had to hunt around an unfamiliar and occupied building until I found said resistor, and changed it out for one approprate for the Zone Expander I just installed. Then I needed to locate the correct circuit for the EOLR which can also be difficult in an existing, occupied building. I then take the wires coming from the panle (which show voltage when metered) to the new zone expander to operate it. The remaining devices of the old zone after the break are also brought to the expander and run off one of its zones. The old EOLR goes in the zone expander, so the panel can monitor the status of that circuit. If there is a problem on the zone expander or one of its circuits the expander will open its controlling circuit, so all is supervised, yet ieverything will operate if an alarm occurs.
Eventually I found the right circuit. But i found a different problem. Remember how I said you had to wire a device in a class B circuit: power goes in on one pair of wires, out on aother pair until you get to the resistor (EOLR).? One pair in, one out is the rule for a device. Imagine my surprise when I find four pairs of wires landed on one device.
This is another typical cob. You put in a new strobe or six and rather than pull a loop to maintain supervision, you just drop in one pair and tap a device. As long as all is well, no one notices. But if a wire comes loose somewhere in your new T-tapped wiring the panel will never know. How could it if the EOLR is in a different branch of the circuit?
I smelled a cob, and my company has the philosophy that you do it right. So I got out my meter and discovered which of the wires has power, and marked it. That pair I brought to the control terminals on the expander. Then I find the resistor, so I know which way is 'out'. I read neither power nor resistance on the other two pairs, but when I test continuity on the red of one pair to the red of another i get continuity. So the other two wires are part of a loop the last technician was too lazy to wire properly. This is a major code violation, the sort lawyers salivate over. So I go power from my expander into the loop. Out from the loop goes on my device, and then the resistor wire goes on the device. Now I have a loop, the whole thing is supervised, the code violation is fixed and everyone is happy. Granted, I haven't fixed the whole building but I'm not being paid tfor that. I fixed the part I'm supposed to work on.
So we did our pre-test on Friday. And low and behold, even though the zone expander sees a trouble, it won't show up at my panel. Why? We took the device apart again. it turns out the loop that had no previous resistance is no reading 6.6K on one side. We shock the circuit with 24 DC volts, and all goes off, but now the 6.6K of resistance has moved to the other wire. Great.
Of course the bulding maintenance rep understands nothing of this. He knows how to change lightbulbs and fix locks, but fire alarms are a black art to him. All he knows is 'it worked the last time we tested it', which means the alarms went off. Since he doesn't go around troubling devices (diconnecting wires to see if a trouble shows up) he never had reason to know about the code violations I fixed. And I'm not putting back the code violation for this inspection. I don't need the grief or the lawsuit if it burns.
What I think happened is that we have a device somewhere in the bulding going bad. It has to be on the wires that had been T-tapped but at this point I don't know where. They installed simple devices, just a coil which operates a diaphram, with a diode so that it won't operate unless polarity is correct. (most notification circuits reverse polarity in alarm, and a capacitor to keep the power levels up. They're old and one or more is probably leaking. But there is no chance in hell the owner will pay for the repair. All he knows that I worked on his alarm, so if anything fails it must be my fault. My boss and I praying that the Jurrassic fire panel will last long enough for the inspection and for us to be clear before something really takes a dump.
That's the way it works in this business. We keep customers by doing good work consistently, so we don't ever have to go back and re-fix stuff. Customers who want the job done right and are willing to pay for it keep us going. But all most people care about is avoiding grief cheaply. If that means leaving some skeletons in the closet, well who needs that key anyway? We'll be called hacks when we did better work than he's ever had before, and left his bulding better off for being there.
They say no good dead ever goes unpunished. I really hope that's not true.