Fire Alarm problem.

[tazz]

can always pull one with Best Western for an extra night, their pretty good to us.
So will see how it goes,

 

[tazz]

Trev just look at you photos again, and can see problem, relay should be connected to CFR and 0v.....this is your problem,

 

[pennychew]

Trev just look at you photos again, and can see problem, relay should be connected to CFR and 0v.....this is your problem,

Thats how it was before we moved them around... we had the aux cable connected to CFR and 0v if i remember right? this is when it seemed to work ok. there were two resistors and connector strip in the NO terminals

 

[tazz]

ok relay should then operate on fire condition, and pull off on reset
the resistors will be for signalling shopping centre fire and fault

 

[pennychew]

ok relay should then operate on fire condition, and pull off on reset

Actually i think we had it in CFT and 0v, the relay needs 24v to pull the A/C contactor in

 

[tazz]

ok CFT is fault relay output and is constant 24v, in fire it powers down.....CFR is fire relay output and has no power util fire condition.
if you had connected to ov and CFT this would course sounder fault, because it is ov switching. CRF is +24v switching

 

[pennychew]

I'm positive this is what the fault is but surely the alarm engineer that's just been out should have been able to terminate the cables in the right positions? Unless he didn't know the relay needed constant 24v but I would imagine they installed it like that in the first place

 

[tazz]

well this is were the problem is, as CFR is switch 24v so is not a constant supply....it not a problem as we can change the primary relay changeover contacts which control the contactors

 

[pennychew]

That would explain why we were reading 24v across Cfr and 0v but when we connected the relay up to these the voltage dropped out and it wouldn't pull the contactor in

 

[tazz]

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