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Sequence of Operations: Basic & Integrated Systems

Posted by ORR Protection on Oct 22, 2020 8:00:00 AM

During the MCFP Virtual Conference series, expert Lee Kaiser, covers sequence of operations when testing a fire system. In the video below, watch as Lee dives in-depth on how to run tests on basic and integrated systems and ensure the sequence of operations is being correctly performed.

Video Transcript:

System Sequences

I want to take this opportunity to teach a couple things at once, and I have a number of animated slides where we step through system sequences. We're going to start really basic to explain a sequences of operation for a fire alarm system and then roll into a sprinkler system, and then into some other systems where we're going to demonstrate opportunities for integrated systems testing to give you the whole picture. 

At the same time, we're going to be going through suppression systems and how suppression systems are intended to work. If you're a potential user of them, or you are a user of them, you will get a better understanding of how those systems are intended to work and how they work in your facility.  If you're a specifier, you get an idea of how you should be writing the sequence of the operation for that system to work.  If you're an enforcer, a good general knowledge is needed for when you run into these systems in your jurisdiction. 

Let's start with a basic fire alarm system. On the screen we've got a picture of an addressable fire alarm panel, and then these lines indicate electrical circuits coming back to the system.  This is an initiating circuit or SLC, which stands for Signaling Line Circuit. We use those on addressable panels, and connected to it are two addressable smoke detectors.  On the other side, this is an output circuit for a building alarm and evacuation. We've got a picture of a horn-strobed device and a circuit labeled NAC.  That stands for Notification Appliance Circuit. When we get a smoke input, it sends a signal to the panel, the panel will go into alarm condition, and it will activate the alarm circuit, so a simple sequence.  Through the magic of PowerPoint, we can animate the slide, have smoke show up, then have the alarm system activate, so it's a simple sequence of operation. 

We're going to take that and build upon it and you will learn as we go.  Let's take that and build it into a sprinkler system.  This sprinkler system is monitored by a fire alarm panel and to do that, we have a couple things.  We have three wet sprinkler zones and those are connected. The electrical devices are connected through monitor modules on an addressable system, and we'll have monitor modules to bring analog circuits onto our digital circuit for the SLC.

One is connected to the tamper switch so when someone closes that valve to the wet sprinkler zone, you've got a supervisory at the panel.  The other one is connected to this water flow switch.  This is a vein-type flow switch and when it activates, it brings on a signal. We see that monitor module as bringing in an alarm, and we program it to know that it's a water flow switch on Zone 1, so we get an alarm.  Then through the program on the panel, we know which one of the two or both of the notification circuits are going to activate. 

The other thing that we have on this are pull stations. First in this sequence, we're depicting the building evacuation, horn strobes in the building, and then another circuit for a water-flow alarm.  This would be an electric bell on the outside of the building that would only activate when we have a water-flow alarm condition. We're going to pull a pull station.  When it activates, the building alarm activates but the water-flow alarm doesn't activate because we have a water-flow alarm, no, right. 

Let's reset the system and now make some space for a fire, okay.  Let's have a fire; sprinkler fuses, water flows, water-flow switch activates, building alarm activates, and since it's a water-flow alarm, we know to activate the electric alarm bell outside of the building.  You see how that same panel has two different sequences, and we have to test that during initial installation and we need to test that.

In this next slide, we are showing opportunities for integrated systems control, so we have kind of, a lot of what we see.  We have an addressable fire alarm panel with a notification circuit for building evacuation and then for our initial signaling line circuit. The first thing we're going to connect to is a duct detector.  That duct detector has a relay and a circuit to power off this air-handling unit if there's smoke in there. This is one place that we test that interconnection and now that we have NFPA4, we call that integrated systems testing.  We would have tested it before but now, we have a real name for that. 

Next we go on to monitor our sprinkler system.  Now, here we have something new, we have a control module.  This is a way to put an output on a system, so we output to release to this intermediate relay, these magnetic door holds, the doors if they are being held open in a corridor and we have a fire alarm activate. We could release those and close them, and again, another opportunity for integrated systems testing. That could be an HVAC shutdown, damper closure, door closure, elevator controls and smoke control.

We're going to go kind of deep into elevator control to show you a place that we're already doing integrated systems testing.  We may not know to call it that because of our current system for enforcing elevator installations.  With elevator emergency control functions, we do a life safety technique, so elevators are not life safety devices, but they have some life safety functions.  We do that through elevator recall control.  When we have a fire in specific places in a building, we will put the elevator system into recall control and if you want to get specific, we'll put in a Phase I recall control.  Here we've got a 4-story building depicted with an elevator.  It has an elevator machine room, where the machinery for the elevator is located. There is a door from the elevator on each floor and outside of that door, we have a smoke detector in the elevator lobby and if we get smoke at one of those detectors, that's going to be where we know we have smoke close to the elevator. We don't want people riding on the elevator car to come out on a floor where there's a fire, so we activate the elevator recall control and recall the elevator down to the level of primary exit access, so we call that primary floor exit discharge or whatever, you know a lot of different jargon for that, but we elevate primary for recall. Usually, the primary floor is the ground level where people normally walk out of the building out to the street and sidewalk, the public way.  If there is a fire on that floor, we go to an alternate level.

We'll explain both of those in our system here. In our diagram, we've got an addressable fire alarm panel.  We have three control modules that give outputs to the elevator system for each one; primary floor recall output, alternate floor recall output, and another thing called fire hat flash.  Let's have a fire on the third floor and activate the primary recall. The fire & smoke makes it to the smoke detector on the third floor. Recall activates elevator car rides to the first floor and doors open.  When we're in recall control, the doors stay open for the fire department when they show up.  The doors open there, waiting on the primary level of access.  They can hop on the car and ride the elevator as they wish to address the fire in the building.

Now, we're going to have a fire on the primary level.  First starts down here, activates this smoke detector, the panel programming knows that, so we don't activate the primary floor recall output, we activate the alternate floor recall output.  The fire alarm system's going off, and in the building it goes to the alternate floor of exit discharge and stays open there waiting for the fire department. 

The last variety of elevator recall control is where we have a fire in the elevator shaft or in the elevator equipment and to depict that, we've got a smoke detector shown in the elevator machine room. When we detect smoke in those locations, we know that the elevator's potentially unsafe to use, and we're going to kind of change the system sequence slightly for that. We're going to have a fire in the machine room; since it's on the primary floor, we're going to activate the alternate floor recall and it will go to the alternate floor, which is the second floor on our diagram here. Then we're going to activate the fire heat flash and we're going to use this control module to send additional input so that the little fire hat, if you guys have ridden an elevator before, you see the little fire helmet indicator.  When it's in recall control, it should be lit but when there's a fire making the elevator potentially unsafe, it will start to flash, so when the fire department shows up and that hat's flashing, they should be trained to know that they're either not supposed to use the elevator or they're taking increased risk to use the elevator. 

Let's have a fire in the machine room, and when that smoke detector activates, the building fire alarm system goes off, alternate floor recall activates, and then the fire hat flash activates. When the fire hat's flashing inside the elevator car it's waiting for the fire department to see that before they use the elevator. 

While we're arguing integrated systems testing, here's how we're doing it.  Most states have a state mandated elevator inspectors.  How do we do it in Ohio?  Do we have an elevator inspector?  Usually, the elevator inspector is testing this.  Initially, every year, they're testing this whole sequence to make sure this works.  At the same time we have another guy testing the fire alarm system.  He's making sure that we're sending these outputs correctly. They usually don't come together except for one time when the elevator's first installed and that's when we're doing integrated systems testing, so it's not as though we're not doing it, we just have a more formal name for doing it and a document to follow as we perform integrated systems testing.  

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