Replacing a Fire Alarm MCP (manual call point)

martinwinlow · Jun 9, 2022

Hi All,

I have been tasked (as island resident hotel handy-man - for my sins) to replace a Emergi-lite MCP (no other details availabe) with aKAC 'MCP1' but the wiring is less than obvious, even with the MCP1's wiring leaflet. I have attached pics of each unit's innards as well as the relevant bit of the MCP1's insteuctons leaflet below. Any advice very welcome.

MW
Isle of Colonsay
Argyll

telectrix · Jun 9, 2022

connect wires from unit into 1 and 4. if you have a multimeter, the wires shoud read approx. 70 ohms.

martinwinlow · Jun 9, 2022

telectrix said:
connect wires from unit into 1 and 4. if you have a multimeter, the wires shoud read approx. 70 ohms.

Hi,

Thanks for replying.

Do you mean 2 x red wires into 1 and the 2 x black wires into 4?

And do you mean 470R and and which wires (sorry)?

MW

Yozza19 · Jun 9, 2022

Black in 1 and 2 and red in 3 and 4 only puts a 470 ohm short on when in fire mode it is triggered into fire as a 470ohm short

martinwinlow · Jun 10, 2022

Hi Yozza19 - Thanks. I'll give that a go.

skidmark · Jun 11, 2022

martinwinlow said:
Hi All,

I have been tasked (as island resident hotel handy-man - for my sins) to replace a Emergi-lite MCP (no other details availabe) with aKAC 'MCP1' but the wiring is less than obvious, even with the MCP1's wiring leaflet. I have attached pics of each unit's innards as well as the relevant bit of the MCP1's insteuctons leaflet below. Any advice very welcome.

MW
Isle of Colonsay
Argyll

hi
for future ref it doesn't matter as long as your positives and negatives are together you could have put your negs in 3 and 4 and your pos in 1 and 2 its just a switch with a 470 in it it's not polarity sensitive

martinwinlow · Jun 11, 2022

Noted, thank you. Every day is a learning day... MW

littlespark · Jun 11, 2022

Although you have had many suggestions, and i understand you may be the only competent person on the island... but would you working on this system invalidate any insurances the hotel owner may have if there was to be an incident.

martinwinlow · Jun 12, 2022

littlespark said:
Although you have had many suggestions, and i understand you may be the only competent person on the island... but would you working on this system invalidate any insurances the hotel owner may have if there was to be an incident.

Maybe, but not detecting a fire in the first place might be a bit more important when trying to explain to guests’ relatives why they were burned alive whilst waiting months for a ‘qualified engineer’ to get here - assuming one was even prepared to drive 2 hours to Oban, sit on a ferry for 2.5 hours (each way) AND spend at least a night in the (not inexpensive) hotel all to connect just 4 wires. Call me old fashioned if you will…

IzzyS · Jun 13, 2022

I don't work on fire alarms so this may be a daft question, but shouldn't the EOL resistor be at the end of the line? How does the panel detect an o/c on the outgoing wiring connected after that MCP? Only routine call point testing would show a fault, which could result in there being non-functioning call points when they are actually needed?

IzzyS · Jun 13, 2022

IzzyS said:
I don't work on fire alarms so this may be a daft question, but shouldn't the EOL resistor be at the end of the line? How does the panel detect an o/c on the outgoing wiring connected after that MCP? Only routine call point testing would show a fault, which could result in there being non-functioning call points when they are actually needed?

Sorry, just realised that it's not an EOL, it's in series with the switch, so I guess it's there so the panel doesn't see a short. Good job I don't touch fire alarms.