Ais/Vhf aerial tripping trip

P

paddywackcocker

Well-Known Member
Joined
18 May 2003
Messages
390
Location
Med
Visit site
Thoughts please,
Remote rail mount VHF aerial.
Hp-33a Ais.
Icom Vhf dsc radio, on its own mast head aerial.
All works great but when on shaw power, every now and again the mains (on board) will trip.
Any way got this nailed down to the remote aerial.
Even when I swapped it to the vhf as soon as I tried a radio check transmission 'click' there goes the trip.
Not connected all is fine.
Any idears how/why this should/can happen?
 
I guess it's down to a leakage to earth from your 240v circuits via the aerial and the rail it's mounted on - but I dread to think how such a leakage could be occurring through the (presumably) 12v radio. Sounds like there's something seriously, perhaps dangerously, amiss with the 240v installation.

Pete
 
That's the weird bit, wip VHF aerial (plastic mount, rail isolated from boat).
No problem with any other electrics or reception, never trips, ais & VHF on 12v circuit.
It's not the worst prob in the world because all fine when not hooked up and it reminds me to turn the instruments off but why, how could a aerial course a trip only on transmit
 
I wonder if the battery charger has a problem? It does seem that the pushpit is grounded. Is that normal? Is the mast grounded - ie, is there continuity between it and the pushpit? Is the masthead aerial fitted via a plastic bracket or is its coax screen electrically attached to the mast/rigging? (why does one work and the other doesn't)
Simple to wrap a bit of tape round the pushpit before fitting the aerial and meter for volts between the two. The installation instructions for the unit mention a ground wire, where did you connect it? (not the green/yellow mains ground I hope.) It's a signal ground not a safety ground and would go to the dynaplate if you have one.
 
Got that but this is a plastic "aerial/whip mount" so it is completely insulated from the boat (well maybe not).
It only pops trip if, ais fires off transmission, or VHF.
This took a lot of isolation to narrow it down to the whip type aerial. Now this could be at fault but why and how can it back up and trip the 240v system and only when systems go to transmit.
Like I said have tried it on both units and it acts the same. No prob with transmission just that it pop the trip if your on hook up. Not a prob just blinking weird and a head boiler
 
Sorry my post above entered before your second showed up! If you ignore the fact that the mains trips, does the coastguard give you a "loud and clear" when you test the VHF (and does it draw about 5 amps when you PTT)? I think the aerial may be faulty and some of the power is getting to the braid, which in turn is connected to ships ground and then possibly through the battery charger to the breaker which will trip if it senses ground current. Can you check the plug is fitted properly?
 
Billjratt said:
Sorry my post above entered before your second showed up! If you ignore the fact that the mains trips, does the coastguard give you a "loud and clear" when you test the VHF (and does it draw about 5 amps when you PTT)? I think the aerial may be faulty and some of the power is getting to the braid, which in turn is connected to ships ground and then possibly through the battery charger to the breaker which will trip if it senses ground current. Can you check the plug is fitted properly?
Click to expand...
Plug is treble checked, and is ok.
Will check amperage. Should there be a reading between shield and cor at plug end? and if so, what?
Radio check came in ok, only did it twice (didn't won't join that team) reply was loud and clear on both aerials, though the trip popped on the whip transmission but remained uninterrupted.
 
Don't mess around and guess. Get a qualified professional to check your electrics. Your life may be in danger.

Earlier this summer I started getting a "tingle" from my guard rail every time I climbed on board when in the marina with shore supply connected but not when disconnected. The local electrical expert checked all the boat electrics and made some changes. No more problems.
 
paddywackcocker said:
Plug is treble checked, and is ok.
Will check amperage. Should there be a reading between shield and cor at plug end? and if so, what?
Radio check came in ok, only did it twice (didn't won't join that team) reply was loud and clear on both aerials, though the trip popped on the whip transmission but remained uninterrupted.
Click to expand...

With the cable disconnected from the antenna there should be no circuit between shield and core.
 
You must log in or register to reply here.

Share this page

Top