MCP Testing

MCP Testing

Manual Call Point is a device for the manual initiation of an alarm.

Manual fire alarm activation is typically achieved through the use of a pull station (term used in USA & Canada) or call point (term used in Europe, Australia, and Asia), which then sounds the evacuation alarm for the relevant building or zone. Manual fire alarm activation requires human intervention.

Manual Call Points (MCPs) are referred to or referenced by different names in various regions worldwide like Break Glass Units (BGs), Pull Stations, Push Buttons, Alarm Points, etc.

When should a Manual Call Point be used? In the event of a fire in a building; or if there is no automatic detection activated by the installed heat & smoke detection or any other detectors; or if you discover the fire personally and if there is an emergency condition – you need to activate the Manual Call Point to trigger the Fire Detection And Alarm System (FDAS) in the building so that the system initiates the necessary notification devices and sends signals to many other third party systems (Voice Evacuation, Emergency Lighting, Smoke Control, Lifts, etc.) in the building.

How to Activate a Manual Call Point? There are different types of manual call points.

1. Break Glass Unit – Break the glass, and then the signal will be sent to the system

2. Pull Station – Pull the lever, and then the signal will be sent to the system

3. Break Glass with Double Action cover – Lift the cover and break the Glass

4. Pull Station with double action cover – Lift the cover and pull the lever

5. Push Button type – Push the button, and the signal will be sent to the system

There are many different types; most often, when installed for FDAS, they are installed in red housing or casing for easy identification; however, in some jurisdictions, these can be other colours for architectural aesthetical purposes. It is always important to check with the authority having jurisdiction and to ensure the MCPs are readily recognisable, easily identified and signed as per the local guidelines and regulations.

Before starting the job, take the proper work permit and inform to all the respective departments. Also, do force the respective logics or interlocks if any (like fire suppression systems activation etc).

§  Remove all the screws and remove the glass cap from MCP.

§  After removing the glass cap from MCP,  the switch inside it activates so alarm appears on Fire alarm panel and the hooter is activated.

§  Acknowledge the alarm or silence the hooter on the fire alarm panel.

§  Note down the alarm tag and descriptions from the HMI or workstation. The alarm details must match with the MCP tag number and installed location.

§  Confirm the MCP activation status from the respective graphics page. You have to visually identify the color change signals of the respective MCP on the graphics.

§  Check the + 36 Volts DC Supply on Monitor Module between terminal 1 and 2. (This is the circuit module inside the MCP).

§  Check all the wire connections on Monitor Module, the push button contact if it found loose then tighten them fully.

§  Ensure resistor leads are completely tightened on to the terminals of the circuit in MCP.

§  Clean the MCP dust by brush and cotton cloth.

§  Fix the glass cap of MCP and fix all screws. It should be fully tightened. If it is loose alarm reappears.

§  Reset the alarm signal from the Fire Alarm Panel.

§  Now MCP is working now in Normal condition.

§  Repeat the above procedure for all the remaining MCP’s.

§  Normalize the forced interlocks or logics if any.

§  Close the work permit.

Note: The mentioned voltages, terminals, circuit module names may change as per the vendor or model of the Manual Call Point.

As per UAE Fire and Life Safety Code:-
🔥 The manual call points shall be used only for fire alarm initiation. In addition, all manual call points within an occupancy shall be of similar design.
🔥 Distribution of the manual call points should be such that the travel distance should not be more than 61m to reach the nearest manual call point.
🔥 These figures are to be reduced to 25m and 16m in limited mobility areas and where processes of the area result in a likelihood of rapid-fire development.
🔥 A Manual Call Point shall be installed within 1.5 m from the exit door opening.
🔥 The manual call points shall be installed generally at the height of 1.2 m, above floor level, and in plain, accessible, well-lit, and free-hindrances places.

If you would like to discuss further with us on MCPs and FDAS, don’t hesitate to get in touch with one of our technical experts.

T-Tapping in Fire Loop Line

 T-Tapping in Fire Loop Line

A fire alarm “T-Tap” is merely a parallel tap into the loop. The reason T-Tap wiring is allowed is because communications are being supervised to the device level. T-Tapping the different legs of the SLC provide multiple communications paths of the field devices and control equipment.
The answer to the question of how many T-Taps is allowed --- is "It Depends". It depends on the manufacturer and it depends on how easy the installer wants to make the system for the technician when servicing the system for the coming years. On a conventional system “T-Tap” not working.

Style 4 wiring (somewhat similar to Class B wiring), which is the data-loop or signaling line circuit (SLC), allows an unlimited number of T-Taps, at least for most manufacturers. Signaling Line Circuit (SLC), carries signals in the form of data between the panel and the input and output devices. Canada calls "Class B Level 1" "Data Communications Link (DCL) Style B". Someone called Initiating Device Circuit (IDC), its carries signals from the input devices to the panel.

Field Devices Connected to an SLC/DCL/IDC.

Input

·        Smoke Detectors

·        Heat Detectors

·        Combination Smoke/Heat Detectors

·        Pull Stations

·        Alarm and Supervisory Input Modules

Output

·        Control Relays

·        NAC Riser Modules

o   24 VDC Audible

o   24 VDC Visible

o   24 VDC Combination Audible/Visible

o   Audio for Speakers (Direct Current (DC) blocking capacitor allows 70.7 VAC 200-20KHz through) independent of other audio.

o   Firefighter’s Phone

Every device on a Signaling Line Circuit is a T-Tap for the Panel.

 
Long Star-Taps

Most fire alarm systems that use Style 4 wiring for the SLC are electronically connecting every device directly to the terminals of the fire alarm panel. Being wire nutted at all junctions, electrically the wire loop is a single pair of copper conductors. 

For all practical purposes, all devices on the loop are connected directly to the panel, and the panel can't tell the difference between home runs to each device and a single daisy chain. 

Yes, the installed wiring may daisy chain to 75 devices in a straight line, but electrically, every last one of them is connected directly to the terminals of the fire alarm panel. 

For these types of systems, the wires can be thought of as having a long star-tap. 

Later Servicing the System

The real concern with the T-Taps is with the later servicing of the system. When trying to find a ground fault or bad device. A limited number of T-Taps makes it easy to divide up the system. 
Not enough T-Taps and the technician has to guess where the wires run through the building. Too many T-Taps and the technician has to pull a lot of T-Taps apart to get an idea of where to find the faulty device or wiring. 

Manufacturer's T-Tap Limit

The manufacturers that limit the number of T-Taps have an input side and an output side to each device on the SLC. Here the panel itself is creating a map of the SLC wiring system. If there are too many t-taps, or if the ins and outs of the devices are not wired according to the installation sheets, the panel's created maps become useless for later servicing. 

How Many T-Taps

When trying to determine how many T-Taps are allowed, consult the manufacturer' installation sheets, and then decide on how easy the servicing of the system should be in the coming years.

If you still aren't sure how you manage your building / establishment loop line, feel free to get in touch with one of our experts via ssaintegrate@gmail.com. Before selecting vendor / installer check and verify they are authorized or not to execute your Fire Detection & Alarm system work. Its mandatory Fire Detection & Alarm System (Edwards, ESSER, Notifier, Autronica, Cooper, BOSCH & GST etc) commissioned by certified professional.