Black round battery isolator 'iffy' - solution = ?

[Emerald Fox]

I had a quick look on Google but can't find the image(s) any more, so here's my post from August about battery isolator switches:

 

http://www.canalworld.net/forums/index.php?showtopic=78451&hl=

 

We were told, in July, our isolator might be 'dodgy' as current was not exactly zero when in the OFF position. When leaving the boat last week, last thing to do was turn the black round switch to 'OFF' and I saw the electrics were still on (lights & water pump still working). I tapped the switch and the lights went off. I tapped it again and they came on. I tapped it again and they went off, and I thought "That's good enough!" and away we went.

 

At the marina/office, our final point of call, I asked if they'd like to replace the switch for us whilst we're away - the answer was we should open it ourselves and clean the contacts/tighten stuff up. Also, that the isolator switch we have is a 'cheapy' (true - I have seen the same for sale in chandlers for around 20 Pounds) and that what we really want is an outrageously expensive model.

 

This is my first job when we get back to the boat. And I'm no electrician. (if you are, and would like to check our electrics in general anyway, and are near Sowerby Bridge, could you PM me?)(our wiring in the control box has been described as "a mess - but as everything works, don't worry too much!")(and we don't really have much electrically-operated stuff in this boat anyway, so must be fairly simple).

 

1. What are these expensive models? Ours says OFF-1-BOTH-2. I have already asked how this is supposed to work (and know, assuming the wiring is correct - which I don't know).

If I got a new unit, 'expensive model', would the wiring/contacts sort of be in the same places for an easy swap around?

 

2. Does anyone have photos explaining in easy steps how to open one of these cheap models, and how to tidy them up inside? Has anyone done this 'cleaning of contacts' - or should I just buy another new cheapo unit (or expensive one)?

I'm naturally worried that upon opening this switch, springs will fly everywhere and nuts will drop onto the floor and roll under the cooker to be grabbed by spiders and scuttled away to their dwellings.

 

3. I imagine I should disconnect the batteries first, just in case I'm fiddling around at the switch's innards and sparks start flying?

[Tony Brooks]

If this is switching the alternator output along with other things I would be a bit wary about trying to clean the inside. If it decides to go open circuit when the engine is running you could fry the alternator.

 

If this were my boat I would change to a correctly wired split charge relay (or VSR) and a pair of decent master/isolator switches. Manual switching lets mistakes in the operation cause problems. This could be as simple as flat batteries or a blown alternator. With master switches you just operate them when you get on the boat and again when you leave it, not maybe three times a day.

[Keith M]

If you are going to change the switch look at the blues seas equipment

 

They are very reliable and reasonably priced.

 

Keith

[Rickent]

We have one of those switches but also a battery isolator switch next to it that kills all the power on the boat.

[frangar]

If you are going to change the switch look at the blues seas equipment

 

They are very reliable and reasonably priced.

 

Keith

 

Seconded!!

 

Cheers

 

Gareth

[Robbo]

If your looking also for a "split charge relay" as well as a battery switch. Blue sea do this pack which is recommended...

 

https://www.bluesea.com/products/7650/Add-A-Battery_Kit_-_120A

 

In normal use you would just use off/on and let the relay join the banks together when needed. If your starter batter is flat you can turn to combine mode to manually join both banks together.

[ditchcrawler]

If your looking also for a "split charge relay" as well as a battery switch. Blue sea do this pack which is recommended...

 

https://www.bluesea.com/products/7650/Add-A-Battery_Kit_-_120A

 

In normal use you would just use off/on and let the relay join the banks together when needed. If your starter batter is flat you can turn to combine mode to manually join both banks together.

Is 120 Amps the rating of the switch, if so watch out if you have an inverter onboard.

[Robbo]

Is 120 Amps the rating of the switch, if so watch out if you have an inverter onboard.

120amp is the relay rating. 350amp continuous for the switch, as well as...

 

Continuous Rating 350A

Intermittent Rating 525A (5 min)

Cranking Rating 10 sec 1000A

Cranking Rating 1 min 750A

[Emerald Fox]

Hmm... thanks for replies... but don't really help me. I fears I am going to have to disconnect the batteries then have a poke around at this black round 'isolator switch' thingy.

If anyone knows of helpful electrickery-knowledgeable folk in the Sowerby Bridge area, PM appreciated!

Also, again, if anyone has dissected one of these switches, it would be nice to see photos of the innards.

I'd be happy to buy a more expensive (and better!) switch, of course - what we have is what came with the boat, and not sure of the age of our current switch (no pun intended!).

[Keith M]

Audlem Boat Company are not that far away

 

Keith

[ditchcrawler]

Hmm... thanks for replies... but don't really help me. I fears I am going to have to disconnect the batteries then have a poke around at this black round 'isolator switch' thingy.

If anyone knows of helpful electrickery-knowledgeable folk in the Sowerby Bridge area, PM appreciated!

Also, again, if anyone has dissected one of these switches, it would be nice to see photos of the innards.

I'd be happy to buy a more expensive (and better!) switch, of course - what we have is what came with the boat, and not sure of the age of our current switch (no pun intended!).

There is a fine selection of switches here http://www.asap-supplies.com/marine/battery-isolator-switches

[David Mack]

Audlem Boat Company are not that far away

Really??

 

"This is a trip of 92 miles, 3¼ furlongs and 105 locks from Sowerby Bridge Junction to Audlem Wharf.

 

This will take 55 hours and 47 minutes which is 7 days, 6 hours and 47 minutes at 7 hours per day."

[FadeToScarlet]

Hmm... thanks for replies... but don't really help me. I fears I am going to have to disconnect the batteries then have a poke around at this black round 'isolator switch' thingy.

If anyone knows of helpful electrickery-knowledgeable folk in the Sowerby Bridge area, PM appreciated!

Also, again, if anyone has dissected one of these switches, it would be nice to see photos of the innards.

I'd be happy to buy a more expensive (and better!) switch, of course - what we have is what came with the boat, and not sure of the age of our current switch (no pun intended!).

I didn't take photos when I took one apart, but if you remove it from the wall and disconnect all cables, you'll be able to unscrew the back.

 

Inside, there's a segment of copper that contacts one, both, or neither of the contacts inside to select which battery/batteries you want to use.

 

The.segment can become loose, so it doesn't turn when you turn the knob on the front. I think if you tighten the screw on the side of the knob opposite the red locking button, it tightens it up again.

[Emerald Fox]

Really??

 

"This is a trip of 92 miles, 3¼ furlongs and 105 locks from Sowerby Bridge Junction to Audlem Wharf.

 

This will take 55 hours and 47 minutes which is 7 days, 6 hours and 47 minutes at 7 hours per day."

 

74 miles by road says GoggleMaps. It's OK - I'm used to doing 105 locks before breakfast!

[Emerald Fox]

 

 

I didn't take photos when I took one apart, but if you remove it from the wall and disconnect all cables, you'll be able to unscrew the back.

 

Inside, there's a segment of copper that contacts one, both, or neither of the contacts inside to select which battery/batteries you want to use.

 

The.segment can become loose, so it doesn't turn when you turn the knob on the front. I think if you tighten the screw on the side of the knob opposite the red locking button, it tightens it up again.

 

Thanks - that's helpful. Copied to WORD for printing and taking with me!

I am brave to have a go at doing stuff, but I don't like playing around with electrics - bit like brain surgery.

If I can get a 'professional' to come and help whilst I'm/they're at it, that'll be better.

We have made great progress with this old tub, happy with all the work we've done, still have a few kinks to iron out.

If blacking next Summer, that we are doing ourselves, goes without hitch, and we get a new tiller bearing, and another hull survey shows all to be OK (last one Jan 2014) then we're 99.9% good!

Edited November 2, 2015 by Emerald Fox

[5thHorseman]

Really??

 

"This is a trip of 92 miles, 3¼ furlongs and 105 locks from Sowerby Bridge Junction to Audlem Wharf.

 

This will take 55 hours and 47 minutes which is 7 days, 6 hours and 47 minutes at 7 hours per day."

They will come to you using a contraption with wheels. Much quicker

[Keith M]

Really??

 

"This is a trip of 92 miles, 3¼ furlongs and 105 locks from Sowerby Bridge Junction to Audlem Wharf.

 

This will take 55 hours and 47 minutes which is 7 days, 6 hours and 47 minutes at 7 hours per day."

 

Good competent electrical engineers are very hard to find

 

Keith

[ditchcrawler]

 

Good competent electrical engineers are very hard to find

 

Keith

Yes I know very few electrical engineers, I know some very good and competent electricians though