Sperry Marine Bridge Watch Monitoring System (BNWAS)

This is a  container ship. Ship crew has complaint about the bridge watch monitoring alarm has continuously giving visual and audio alarm once the watch alarm generator switches on. Try to press the reset button on reset unit at bridge did not help. The worst is that the alarm has trigger all the way to all alarm panels including Captain's day room where Captain has difficulty falling asleep. So they have to completely switch off the unit.
I attended the ship and checked all fuses and power supply to main watch alarm terminal module were all present. Checked the parameter by putting dip switch in terminal module from 0 to 1. Put the key switch at watch alarm generator to off position. The word - PRO will present. Checked the parameter in the unit from 000 to 019 and it should be shown as the manual setting. I have selected 001 which is owner setting as per IMO requirement. Lower limit alarm = 3 mins, Higher limit alarm = 12 mins. Delay in buzzer alarm = 15sec. Delay in accommodation alarm = 15sec. Delay in crew alarm = 90sec. You can also set to show count down(CD) in counting down state or dormant state = 1 or 0 in parameter.
Found the problem to the constant alarm been activated was due to one of the reset unit been activated(short circuit)  and causing the unit to permanent reset. Remove the pin 59 - 29 Ext Device which causes the shorting. The watch alarm unit works in a parallel way where either reset unit within the network shorted, all reset unit will be shorted. So looking at the terminal module, 43 - 13, 45 - 15, 47 - 17, 49 - 19, 51 - 21, 53 - 23, 55 - 25, 57 - 27, 59 - 29, 60 - 30 should measure +24Vdc. If no voltage were received, it means one of them must be shorting. How then do you know which one is shorting since all connected in parallel? Removed wire 43, 45, 47, 49, 51, 53, 55, 57, 59, 60 and connect to a temporary terminal block. Measured in ohm to 13, 15, 17, 19, 21, 23, 25, 27, 29, 30 respectively. Means the red probe goes to 43, the black probe goes to 13 in ohm range using a multimeter. After fixing the problem, tested count down of 12 mins, 6 mins and 3 mins working perfectly ok. Also tested the time diagram works as per IMO requirement.
Please see the parameter setting below and time diagram according to IMO requirement.

This type of BNWAS is simple and easy to install and operate. The cost is also reasonable consider the IMO regulation kick in for most of the ship owner to fulfill the IMO regulation requirement. For enquiry, please contact Sperry Marine for quotation
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