Fire Alarm problem.

[pennychew]

Well tomorrow, we will test each section at a time, and work our way through it, should be a major problem.

I hope that's a typo!!

 

[tazz]

I hope that's a typo!!

ooops sorry should not be a major problem.....think it time for sleep...lol

 

[pennychew]

Hope to see you tomorrow then!

 

[pennychew]

Just got the old relay out of the van and checked the resistance in the coil, was only 8.6 ohms so would have been trying to pull nearly 3amps from the alarm panel. This confirms to me that was the original fault, they added a separate enclosure, psu and a new panel to get round this. Probably only needed the £8 relay pulled out and swapped in the first place... Well see what today brings anyway

 

[telectrix]

Just got the old relay out of the van and checked the resistance in the coil, was only 8.6 ohms so would have been trying to pull nearly 3amps from the alarm panel. This confirms to me that was the original fault, they added a separate enclosure, psu and a new panel to get round this. Probably only needed the £8 relay pulled out and swapped in the first place... Well see what today brings anyway

you seem to have forgotten that the relay coil is inductive and the impedance will be higher than the resistance.

edit: forget that. it's dc. even so, that reading for the coil is ridiculous. should be somewhere around 1K.

 

[pennychew]

To be honest I've only checked one other relay coil before and I'm sure it read around 4.5k ohms

 

[pennychew]

Although I know what you are saying and my calcs are wrong!

 

[telectrix]

no, it's me was wrong. forgot it was d.c. this makesan interesting read. how an inductor behaves in a d.c. circuit.

Inductor in a DC Circuit

 

[pennychew]

I'll have to read it later mate, as punishment for putting Manchester off til tomorrow and not taking the wife and kids out I have to paint the bathroom and re-silicone round the shower :-(

I have to get it done as well cos she's kicking off!

 

[telectrix]

as long as she's playing against england, she should have an easy time at kick off. anyway, who wants to take wife and kids out in this weather. they'll olny blame you for the rain.

 

[trev]

Well, it's sorted. Thanks to our resident fire alarm expert and all round thoroughly good bloke Dave (Tazz)

 

[pennychew]

Just to second what Trev has already said, tazz is a top top bloke who definitely knows his stuff, found the fault and came up with a solution (which required a last minute dash to maplins!) but he gets the job done and it's all sorted.

Thanks for sorting the job out for me but also thanks for showing me how you sorted it and explaining the processes as you went along. Good to see a pro at work! And invaluable experience for someone starting out like myself.

 

[tazz]

Nice to meet you both today, and for your kind comments.....was a strange one with the current limiter kicking in, but thats the Gent panel....well thanks for the warm welcome, back South tomorrow...

 

[Guest77]

Windy and 17 degrees? This is our summer mate.

I thought you meant the local talent by that comment trev

 

[tazz]

Just thought I would explain the situation, my help when working on Gent panels....The objective was to switch a 24v relay, which inturn switch a 3 phase contactor. On testing the 24v relay it drew 300mA, The Gent fire panel could only switch 100mA on its fire output. Therefore the current limiter kick in, and disconnected the output. Lucky for us, there was a 1A 24v supply installed next to the panel. So on buying a smaller 35mA 24v relay with 10A contacts, the Gent panel was able to power this relay, with inturn switch the 300mA relay via the power supply...This final relay, with mains rated contacts, then power the contactor.