Why your fire alarm shows a supervisory signal after the sprinkler inspection

It's one of the most common calls we get. The sprinkler company finishes its inspection, packs up and leaves. Later that day, or the next morning, the fire alarm panel is beeping and showing a valve supervisory signal. In most cases nothing is broken. A tamper switch on one of the sprinkler valves just isn't sitting where it should be, and a quick check before the sprinkler crew leaves would have caught it.

What a tamper switch does

The valves that control water to your sprinklers, such as the PIV (post indicator valve) out near the street and the OS&Y (outside stem and yoke) valves on the riser, each have a supervisory switch mounted on them. Most people call it a tamper switch. Its job is to tell the fire alarm panel when a valve isn't fully open, so a closed valve doesn't go unnoticed.

When the switch reports that its valve is off normal, the panel shows a supervisory signal. That isn't a fire alarm, and the horns and strobes don't go off. But the panel keeps sounding until the condition is cleared.

A red Potter OSYSU-2 valve supervisory switch mounted on a sprinkler control valve, with its wires running to the fire alarm system — A Potter OSYSU-2 valve supervisory switch on a sprinkler control valve. If the valve is turned off fully open, or the switch gets bumped out of position, the fire alarm panel reports a supervisory signal.

Why it shows up after a sprinkler inspection

During their inspection, the sprinkler contractor turns the valves. That's part of the job, and the panel going into supervisory while they work is expected. The problem is what happens at the end. Either the valve isn't returned to fully open and the switch isn't reset correctly, or the mechanical tamper device gets knocked out of alignment while the valve is being turned. When that happens, the valve can be fully open and the switch still tells the panel something is wrong.

It's an easy thing to miss. The sprinkler crew is focused on the sprinkler system, and the fire alarm panel is often in a different room from the valves.

Why it turns into a service call

Once the sprinkler crew has left, they may not come back for it, at least not quickly. So the call comes to us instead, and one of our techs goes out to re-align the tamper device and get the panel back to normal. It's a quick fix, but it's still a service call, and one that didn't need to happen.

Check the panel before the sprinkler crew leaves

This takes a couple of minutes and can save you the call:

Before the sprinkler crew packs up, look at the fire alarm panel, or ask them to. It should show the system as normal, with no supervisory or trouble lights on.
If it shows a valve supervisory signal, ask them to check that every valve they turned is fully open and that its tamper switch is seated correctly.
If the panel still won't clear, ask them to stay while you call your fire alarm company. It's much easier to sort out with everyone on site.

If the panel shows normal before they drive away, you're done.

If it's already happened

If the sprinkler crew is gone and your panel is showing a valve supervisory signal, give us a call at (626) 300-0877. We'll send a tech to re-align the tamper switch and get your panel back to normal, whether or not we're your regular fire alarm company. And if you'd like us to look after your fire alarm system going forward, we'd be happy to help. We offer both 24/7 fire alarm monitoring and fire alarm testing and inspections.

PANEL STILL SHOWING SUPERVISORY?

We'll get it back to normal.

Call (626) 300-0877 or send us a message about service, inspections or monitoring.