Engine Room Artificer
Hot Rolled
- Joined
- Feb 28, 2007
- Location
- Gosport Hampshire UK
OT as not machine tool related.
Some of you helped me in a recent thread with inverters causing harmonics in the ship supply system here:
http://www.practicalmachinist.com/v...tor-phase-relationship-3-phase-supply-245325/
I have another problem regarding the same vessel.
We connect to shore supply when alongside and it is available to save running ship's generators, the shore cable and associated equipment is rated to 180A but be normally draw about 120-130A. The power is passed through a shore converter which allows anything in and automatically converts it to the correct frequency and voltage.
We are berthed in Malaysia and the maximum shore power available on one socket is 100A; normally in this situation we connect into 2 sockets which come into a connect into a 'joiner' box, into which we connect the ships 180A plug. Each plug on this jetty has an earth leakage trip as well as the standard 3 phase current trip. I am finding the earth leakage trips will not make at the same time, ie, make A and B trips and vice versa.
Each plug is wired with 3 phases and earth (no neutral), each plug is wired with the same phase to pin and I have checked continuity through the joiner box
Can anyone think if I am missing something why the earth leakage breaker should be fighting.
If I pare the ship's load back to about 95A I can successfully connect through one plug though if I get a transient load such as the fridge compressor cutting in, the main breaker trips on overcurrent.
All help and comments greatly appreciated.
Some of you helped me in a recent thread with inverters causing harmonics in the ship supply system here:
http://www.practicalmachinist.com/v...tor-phase-relationship-3-phase-supply-245325/
I have another problem regarding the same vessel.
We connect to shore supply when alongside and it is available to save running ship's generators, the shore cable and associated equipment is rated to 180A but be normally draw about 120-130A. The power is passed through a shore converter which allows anything in and automatically converts it to the correct frequency and voltage.
We are berthed in Malaysia and the maximum shore power available on one socket is 100A; normally in this situation we connect into 2 sockets which come into a connect into a 'joiner' box, into which we connect the ships 180A plug. Each plug on this jetty has an earth leakage trip as well as the standard 3 phase current trip. I am finding the earth leakage trips will not make at the same time, ie, make A and B trips and vice versa.
Each plug is wired with 3 phases and earth (no neutral), each plug is wired with the same phase to pin and I have checked continuity through the joiner box
Can anyone think if I am missing something why the earth leakage breaker should be fighting.
If I pare the ship's load back to about 95A I can successfully connect through one plug though if I get a transient load such as the fridge compressor cutting in, the main breaker trips on overcurrent.
All help and comments greatly appreciated.