Rick-n-Jo

A little puzzle for the electrical bods here. Comments and opinions welcomed.

A few days ago I was moving "Pleiades" to Saul Junction in the gathering dusk (we had a timber delivery the next day, so looking for a lorry friendly mooring). As I was reversing towards a suitable mooring space, suddenly all the lights went out, and as she is diesel/electric drive and I was making the short journey on battery power only, I lost propulsion as well. Fortunately the wind had fallen to a gentle breeze so I managed to go below and restore power by switching the battery off and on a few times, before we hit anything.

The switch is a BEP Marine item, rated at 600 amps. Contacts are a copper/brass plate rotating over a pair of electroplated copper bolts. Not very sophisticated.

Later investigation showed that the contacts were badly burnt and eroded.



I initially suspected that the culprit was the propulsion motor speed controllers, as these contain several large capacitors that charge up quite abruptly when a battery is first connected, giving a big and noisy spark. However I have a contactor (big relay) fitted, with a 470 ohm 2W resistor bypassing its contacts, which is supposed to charge the capacitors slowly enough to avoid the big spark. To test if this was the cause I disconnected the motor circuit completely, leaving the rest of the boats systems as normal. Reconnecting the battery still generated the big spark. Further elimination showed this to be down to the inverter/chargers.

Oh ho! Suddenly, this appears to be not just a problem with my system, but potentially for any one which has similar equipment.
I have two Victron combi inverter chargers, model 48-3000-35. I'm guessing they also contain capacitors sufficient to cause significant arcing when the battery switch is turned on. I don't know if the problem is worse as these are 48 Volt items. I do know that battery switch failure is not uncommon.

My proposed solution is to do something similar to the motor circuit. I propose to put a 470 ohm 6W power resistor in series with a push button switch across the battery switch so that pushing the button for 20 seconds or so will bypass the battery switch and pre-charge everything before turning on the main switch.

Will this solve the problem? Anything I'm missing? Over to the experts!

Rick

Sue Day of the Horseboating Society has sent the following;

Can anyone help?

Tow appreciated for historic unpowered boat Elland going north. Eventual destination, Standedge on Huddersfield Narrow Canal but any tows north would be appreciated. Boat is usually horse-drawn but lack of time would make a motorboat tow easier. Present location at Autherley Junction area, but this may change as she works north. Boat is 60 feet long.

Contact - Sue Day 01457-834863, 07711-121-056, sueday_horse (at) yahoo.co.uk

Both of Sue's horses are out of action at the moment, one lame as a result of injuries recieved when yobs shot at him with BB guns, the other rather more happily as she is expecting her third foal.

If you can help, either contact Sue direct or PM me.

Rick

Neither my brass tiller tube or swan neck (Z- iron, to use an older term) have been drilled to fit a tiller pin. Any ideas how to drill these, and be sure of getting the holes square and in line? Don't really want a wonky tiller pin, although I've seen plenty of boats that have!

I suppose taking the whole thing off and finding an engineer with a big pillar drill is best, but would rather not have to do that. Some kind of jig, perhaps?

Rick

VOTE PORT!

£80,000 is up for grabs and with your help we can win this money for
Stroud.
A project to rebuild the historic walls of Brimscombe Port has been
selected to face a public vote by Big Lottery Peoples Millions.

Monday -26th - the project will go head to head against a scheme
in Wiltshire for a winner takes all £80,000. Both projects will be
shown on that day's 6pm news on ITV West.

This community led project will save the historic Port Wall from
dereliction by removing the trees and undergrowth that are growing
out of it. The path behind the wall will be widened and improved so
everyone can use it - including wheelchair users and people with
pushchairs. Local people will be trained in heritage skills to repair
and restore the masonry and traditional lime mortar

So what can you do? - Vote please!
The telephone number is
08702 435 802

THE LINES WILL ONLY BE OPEN FROM 9AM UNTIL MIDNIGHT ON MONDAY 26TH.
Votes can only be cast by phone, you can vote up to 10 times from
each of your phones. Land line calls cost 10p, mobile & other
operators' rates will vary.

Please remember to vote in favour of the project whether or not you
receive ITV West. Watch the ITV
West evening news bulletin if you can, otherwise for more
information about the project please visit
http://www.cotswoldcanalsproject.org and follow the links.

Thanks for reading

Rick