Sprinkler/Fire Alarm zoning

[ElectDesigner]

I have attached a diagram of a sprinkler assembly (apologize for the poor quality). My question is how you would zone this on your fire alarm system. This is how I would zone the sprinkler assembly

1. SV-1 : Trouble
2. SV-2 : Trouble
3. SV-3 : Trouble
4. Low Press Monitoring : Trouble
5. Excess press pump: Trouble
6. Flow switch: Alarm

Wet alarm check valve - Not sure??

 

[nhfire77]

View attachment 6893
I have attached a diagram of a sprinkler assembly (apologize for the poor quality). My question is how you would zone this on your fire alarm system. This is how I would zone the sprinkler assembly

1. SV-1 : Trouble
2. SV-2 : Trouble
3. SV-3 : Trouble
4. Low Press Monitoring : Trouble
5. Excess press pump: Trouble
6. Flow switch: Alarm

Wet alarm check valve - Not sure??

None of those would be trouble, all supervisory, execept alarm is alarm. The check valve is internal, it keeps water flowing in one direction only. If some how pressure was reversed, or lost, the system would not drain. It also keeps nasty sprinkler water from seeping back into the water supply. No fire alarm connections.

 

[darrell51]

The three SV switches are not trouble indicators but should be programmed in the fire panel as supervisory signals. If the gate valves are closed, it is not a trouble condition, but a supervisory situation.

The part of the diagram that looks like it conflicts is that you are monitoring an air compressor for high and low pressure? If it is supposed to be a dry riser system, there should not be a water flow switch in a dry pipe.

A water flow switch like a potter VSR is for a sprinkler system with water in the riser at all times. If the system is a dry system, the low pressure on the air compressor should send a trouble condition to the fire panel. The high pressure would be monitoring when water is flowing and the high pressure would be an alarm signal.

I have never connected a wet alarm check valve to a fire panel. I don't know but it probably does not have the ability to turn off water to the sprinkler system and would not need to be monitored.

 

[nhfire77]

Terminology varies but I like:

SV-1: outside (or city side) main tamper

SV-2: inside main tamper

SV-3: Riser #1 tamper, or just 'riser tamper' if there's only one

Riser #1 Low water pressure, or just low pressure

This is a wet sprinkler system. Auto excess pump pressure operation, Kinda weird. That pump must be a circulator to reduce street pressure, total assumption there.


FYI: Most water pressure switches have a high and low side, so you could monitor high/low off one switch. Of course, two is fine.

 

[MichaelGP3]

I'm curious why the OS&Y valve tamper switches require 3 sets of contacts. I'm unsure as to whether they are commercially available even if there was a good reason for specifying them.

 

[nhfire77]

I'm curious why the OS&Y valve tamper switches require 3 sets of contacts. I'm unsure as to whether they are commercially available even if there was a good reason for specifying them.

I know it said os&y, but butterfly valves like that are common here in the northeast. it's a sealed unit, prewired with a 1' whip protruding from a threaded opening.

 

[darrell51]

Double sets of contacts are helpful in situations where the shopping center is monitoring the sprinkler system but the local store wants their suite's fire system monitored as well. I sometimes see there are two fire alarm panels monitoring the same switch.

 

[gadfly56]

3 Contacts?

3 Contacts?

I looked at offerings from System Sensor and Potter Signal. Between them the probably cover 95% of the market for this type of switch, and neither offers a product with 3-pole double throw contacts. Is there a manufacturer spec'd elsewhere in the drawing?

 

[MichaelGP3]

I know it said os&y, but butterfly valves like that are common here in the northeast. it's a sealed unit, prewired with a 1' whip protruding from a threaded opening.

The 10 wires availble on the butterfly valves I've worked with, available throughout the Western Hemisphere and perhaps even further abroad, have a green ground wire, 3 solid color wires soldered internally to one set of form 'C' contacts, and 6 solid colored wires with stripes soldered internally to a 2nd set of form 'C' contacts. Thus you are able to wire 'in' and 'out' on each 'terminal' of the 2nd set of contacts - fully supervising the devices using the common and normally open side - useful if you are wiring one or more of these switches to 1 zone or input module address.

The device cannot be fully supervised (meaning you get a supervisory short signal when a switch is activated and a trouble signal when a wire is broken or cut) using the contact with 3 wires attached. The wiring can be supervised, but not the device, since you are essentially 't-tapping' said device.

How many wires are in the 1' whip of the butterfly valves you are familiar with?

 

[nhfire77]

The 10 wires availble on the butterfly valves I've worked with, available throughout the Western Hemisphere and perhaps even further abroad, have a green ground wire, 3 solid color wires soldered internally to one set of form 'C' contacts, and 6 solid colored wires with stripes soldered internally to a 2nd set of form 'C' contacts. Thus you are able to wire 'in' and 'out' on each 'terminal' of the 2nd set of contacts - fully supervising the devices using the common and normally open side - useful if you are wiring one or more of these switches to 1 zone or input module address.

The device cannot be fully supervised (meaning you get a supervisory short signal when a switch is activated and a trouble signal when a wire is broken or cut) using the contact with 3 wires attached. The wiring can be supervised, but not the device, since you are essentially 't-tapping' said device.

How many wires are in the 1' whip of the butterfly valves you are familiar with?

I believe were talking about the same thing. I'm not sure I've seen three contacts on one device either. We never put more than a single valve on a single monitor/input module, alleviating the supervision issue. They are cheap (imo), and it allows individual valve annunciation.

I think tyco makes a large sealed control valve that is prewired, again, I believe 2 contacts and a ground, not three. The entire valve has to be replaced when the switch goes bad. Those units valves have a sealed area in them containing oil to lubricate the internal moving parts (not the valve in the pipe of course) and occasionally the oil leaks out and causes a ground fault on the switch. Now, you drain the system to replace the valve. I've seen those on a couple of sprinkler water tank valves, located inside a dog house attached to the tank.