Amps Drawn By A Ford Type Relay

Additional sources...

http://www.dan-marc.com/rv-parts-electrical-battery-isolators-seperators.html

http://www.boundlessoutfitters.com/Battery-Isolators-s/11.htm

I agree that you need a continuous duty relay. I use one with my dual batteries in my truck, and it draws less than 10 Amps.

Thanks a lot for the thorough info! Very interesting sources!

Right on!

Yes, for steady state current in a DC circuit you can use your ohmmeter to find the coil resistance for use in Ohm's Law to calculate the current, but why not use the Amp function on your multimeter and measure the current directly?

The bigger question is whether the relay coil is meant for continuous duty; you might try to energize it from your battery and see how hot it gets over time. If it heats up fast and gets too hot to touch you're out of luck.

I don't what type of boat you have, its fuel, and exactly where this relay is going; but make sure you run the bilge fan before you push that button!

Thanks to you too! The boat is a twin engine diesel, so gasoline fumes are not an issue!

Hi! the Perko switch is rated 100 A.

Thanks. Be sure to use a relay rated for *at least* 100 amps and one suitable for marine service.

right!, thank you again!

You're welcome! Lots of good info on this thread so you have no problem finding what you need.

GA for your good post.

Alter your 5 hours to maybe 5 minutes - tops.....

The OP should NOT go with a relay, any relay, that is adding a further P.O.F. and that is the last thing you need on a boat......

He should "Bite the Bullet" and move the switch to a better position, or simply add a mechanical way to turn it on and off if you cannot reach where it is now.

Seem to have very affordable products. Thank you!

sure

I would not consider any DC relay and/or associated control equipment for this application on a boat other than one that is designed and rated for "Marine Service".

Although the cost for marine service rated devices is higher, the reliability is worth the expense.

If you are quarantined to using the boat on small fresh water lakes the risk is small however if the waterway is large or if the boat is going to be used at sea, your safety risk is great.

There is a myriad of marine rated manufacturers available on the internet that provide the equipment and parts you need to make this revision in a safe, reliable manner.

Searching locally I have found this 1500 W (125 Amp in 12V) solenoid for the equivalent of 100U$ a piece. It is sold under the Bull Winch trade mark. Could not find any specific info besides the wattage. Due to it´s shape, one could consider it works by means of diodes, instead of a coil as the Ford type. What do you think?

is it marine rated?

It should be. Will call the store tomorrow. These guys sell marine stuff (which is a good start!) Thanks!

This switch is manufactured here under the name Baron USA....this is a windless reversing solenoid switch for raising and lowering the anchor...it's not used in your type of application, nor would it be suitable....keep looking

http://www.baronusa.net/articulo/solenoid-reversing-12v-4-wire-max-1500w/3292

Baron is a well known outfitter here in Argentina, specialised in yachting This company also has some stores in the US. The picture I posted is of a part sold by a local competitor, but seems to have been done by the same manufacturer. I visited the store this afternoon, and yes it is of no use in my project. Thank you a lot!

Diodes could not and would not interrupt the DC power.

It appears to be a hermetically sealed relay of significant current handling capability.

The factory wiring diagram/schematic should be available from the manufacture in pdf or other picture format for viewing the internal parts.

Consider a solid state switch.

There are power Mosfets available that are capable of switching around 300 amps with no sparking, so no fume control considerations, and, because they are voltage operated, with little to no current in the gate control circuit (other than for maybe an indicator LED if desired), voltage drop on the control line is virtually nonexistent.

In a straight switching mode such as this, ie. either on or off, very little power will be dissipated by the device, so little heat will be generated.

Just about any competent electronics tech. should be able to make one up for you in very little time, and at probably less cost than the relay. For example, an IRL3713SPbF N channel Mosfet will carry 260 amps continuous (maybe a bit less at elevated engine room temperatures, but 2 in parallel would easily do the job), one can withstand an inrush of a tad over 1000 amps, will handle up to 30v with max 20v on the gate and cost you around $5, the tech's time will be a bit more but the circuitry is pretty simple.

Cheers

GA

Hi, The remote operated swich I am looking for is ONLY to connect / disconnect the + prower supply from the battery to the genset.

The cranking current for the main engines is provuded by a completely separated battery bank. The diesel in the tanks is just that (no mixing with any other fuel)

Actually, although Diesel is difficult to light till over 40°C or so, the fumes will explode very easily, when you smell Diesel, you are smelling fumes......

.......as they are often mixed with air.....its still a risk, but nowhere as bad as Petrol fumes of course!!

See Post #6 on this website:-

Diesel-fumes-are-explosive

Of course diesel is safer than petrol, but you still have to play safe. A warm engine room (where many tanks are fitted) on a hot day may cause diesel to gradually fume...therefore its always worth purging the bilge before starting....

Never treat diesel lightly (pun intended!).

Dear OP, simply do not do this. Either do a proper job of moving the switch to a more accessible place, or extend mechanically the switch.

I thought about this and a simple way to do this type of mechanical extension might be using say one of those cheap drain cleaner wires, which can be as long as 10 foot, which are quite stiff in twisting, guide it gently via a few "P-Clips" and use it to "remotely" switch the battery switch....

Here is one:-

Coating it occasionally with WD-40 will stop rust and allow easy movement. Try to keep it as "straight as possible. A flexible plastic tube may be even better....

I have never done it myself, and a certain amount of "tuning" may be needed to get it just right!!

But a REALLY cheap and unlikely to break down mechanical method.....

It may not be possible to bring it to where you sit, but is that needed? I doubt it....

Remember, if your electrical system EVER needs this switch in an emergency, then something is wrong with the boat's electrics anyway....get that fixed first before moving the switch or adding a remote control.....

Its bad enough having relays/solenoids to start your engine on any boat/car/truck/etc., simply don't add anymore of them to your boat when safety is critical.....

Dear Andy, thanks for your input, and concern! I do subscribe to the KISS idea and fully agree with you about safety. This only involves a (non critical) 220V generator. Given the case the realy / solenoid does not work, there is always the possibility of working a little bit in order to by-pass it.