Minerva 80 high ident in one zone

[ImCed]

Hello fellas,

I am working in a ship as an electrical officer. Problem I'm encountering right now is that one of our zone in a loop is having an High Ident alarm.

Let say, In loop B, it is divided in to 3 zones namely zone 5,6,7. They are separated with Line Isolators. Recently, we are receiving High Ident in Zone 5.

All devices within zone 5 has High Ident Alarm except manual call points. Ok, in zone 5, we have 7 sensors, 4pc are smoke detectors and 3pc manual callpoints.

Below are their wiring diagram.

Panel-----B1(M)-----B2(S)-----B3(S)-----B4(M)-----B5(S)-----B6(S)-----B7(M)-----LI-----B8(S)-----B9(S)-----B10(S)-----LI-----B11(M)-----Panel.

So, zone 5 is from B1 to B7. this are installed in the alleyway.

I already replaced the sensor from ionization to high performance optical, already replaced some of the bases, line isolator between 7cand 8, yet,  I still receive same alarms specially when people are comming in and out in the door.

Please enlighten me.

 

Thanks

[Taco]

Any high ident faults ive ever came across just meant the heads needed a good clean. Take them down and give them a good blast with a can of compressed air and make sure the terminals are clean as well

[james.wilson]

are they less than 10 years old?

[ImCed]

On 1/10/2017 at 4:45 AM, Taco said:

Any high ident faults ive ever came across just meant the heads needed a good clean. Take them down and give them a good blast with a can of compressed air and make sure the terminals are clean as well

Hi Taco, I already replaced all heads in the faulty zone, still giving some fault. I was thinking maybe the adjacent zones triggering the alarm. I was also thinking that maybe airflow or pressure difference affecting the system. Because these heads are installed in the alleyway. Whenever we open the door and kept it open from outside, the alarm was triggered. Any ideas? 

Thanks.

On 1/10/2017 at 5:22 AM, james.wilson said:

are they less than 10 years old?

Hi James,

Our system is same as our ship's age, and our ship's age is 14yrs old

[james.wilson]

imced heads as a rule have a 10 yr life, your not on a bp ship are you?

[Taco]

If you're experiencing these faults when you open the door and expose the area to dramatic changes in air pressure and quality, i would say that is exactly whats causing the fault, im guessing you only have these activations on optical smokes?

[ImCed]

On 1/11/2017 at 8:04 AM, Taco said:

If you're experiencing these faults when you open the door and expose the area to dramatic changes in air pressure and quality, i would say that is exactly whats causing the fault, im guessing you only have these activations on optical smokes?

absolutely, it do always happens when somebody forgot to close the door going to engine room where it is ore positive pressure than our alleyway. 

Yes, only smoke detectors having these faults.

I just posted this problem just to extract more info, whether my deductions are correct or somebody has fresh ideas about this case. But I will try to check as well manual call points for loose connections for the sake of personal satisfaction that I checked everything that is possible in my side.

On 1/11/2017 at 6:38 AM, james.wilson said:

imced heads as a rule have a 10 yr life, your not on a bp ship are you?

Noted sir james, but I already replaced this heads with high performance optical (from ionization chamber type), still I got this faults. 

No im not... 

[james.wilson]

Quote

 

a good mate of mine in 1st eng with bp

but as its optical now, room of engine room I'm not sure. From what I've seen I cant see you have enough or any to trigger it?

[Taco]

You wont get high ident faults on mcp's mate, i wouldnt even bother looking there. 

It certainly looks like the air quality is being affected and this is whats triggering the faults.

Could you change the type of detectors to co or heats? That would resolve the issue, other than that, some sort of barrier at the door or extractor fan

[goncall]

if you've changed ion to hpo you will have to change  programming in consys or you will get id  faults, also any faulty device on the loop can cause low and high id faults on other devices, a faulty mcp causing id faults is common only way to prove is to discon one device at a time and link the loop thru and check the levels unless you have a shorting device which speeds up the process its  a pain of a fault to trace 

Edited January 13, 2017 by goncall