|Topic Review (Newest First)|
|05-22-2008 08:52 PM|
I have memories of horn relays sticking at very inopportune times; and of having to get out of my car to rap the starter solenoid with a rock; and of having the outboard raise / lower mechanism fail on a new Mercruiser; and having to replace West Marine combiners any number of times...that's way expensive too, one relay can take out an otherwise very nice battery system.
You can tell I'm not really impressed with the hype. You just can't make a silk purse from a sow's ear.
In my opinion, as has been said before, relays of any kind have no place in a critical aplication, and a boat fits that definition.
|05-22-2008 05:49 PM|
|Islander30Bahama||Correction sorry, Hermatically sealed are a sealed and usually filled with nitrogen built tough to withstand virbration and major heat changes. I was thinking solid state encased in an epoxy substance. The solid state cost a lot more than regular but are worth it in the marine environment if one chooses to go that route. There is a web site deutschrelays dot com that have some wicked awesome marine relays. Probably overkill for the average cruiser but worth it possibly if extended world cruising was in the future for someone.|
|05-22-2008 04:54 PM|
I will dig them up from the basement this weekend and then scan them into a PDF format next week.
As for the mechanical crimps I use the heat shrinkable kind. They have done a very good job helping to prevent corrosion on the trucks that we manufacture. The connections see all kinds of road grime, lots of water, salt in the winter and whatever else chemicals are on the road.
Relays can be good if properly handled. One of my vendors here at work who supplies us with our relays informed me that TYCO has bought out most of the BOSCH relay division and their quality is far worse than Bosch. A hermaticaly sealed relay is encased in a epoxy like material preventing movement of the pins inside this would be ideal for almost any application but then again its a personal preference.
For those of you in major coastal cities you can usually find classes to take to learn from the pros on the do's and don'ts of many different marine subjects. These classes usually fil up rather quickly and some cost will be involved but you will some good hands on experience.
|05-22-2008 04:16 PM|
I'd recommend most strongly against using relays. The idea is good, but consider that each relay means four wires, four junctions, four more failure points, actually six more failure points if you count the relay coil and contacts as well. Or, more failure points since each relay coil needs to be FUSED as well! With separate fuses for each, unless you can afford to lose them all at once.
And it gets worse than that:
I was using a relay very much the same as the one in the picture (a Bosch 30Amp automotive relay) as a horn relay in my car. Worked fine for years, well potted, no reason for any problem. Except, my horn wasn't working. Tore my hair out for two days troubleshooting everything including the relay and everything tested fine--but the horn didn't work.
It turns out those relays are now made by molding the relay housing AROUND the qd plugs that stick out of their base. If the plastic lets go of the metal, you can wind up with the spade plug moving when you connect (or disconnect) a wire to it, breaking the internal contact in the relay. So, you take it all apart and test it, it tests 100% good. You plug the wire back in--and the contact is broken (by literally a millimeter or less) and the damned thing doesn't work.
Do you want six failure points in each circuit? I wouldn't. I'd rather just buy some nice new heavy-gauge tinned wire and extend the wire runs to the new panel. Or, keep the switches below--because no matter how "waterproof" they are, longer wire runs and switches that are above deck are going to be less reliable.
|05-22-2008 04:08 PM|
|sailingdog||LOL, I'd love to see the materials from the USCG course and will PM you an e-mail address if they're in electronic format. Most people don't have the benefit of the taxpayers ponying up for a 2.5 month course...so mechanical crimping is probably a better solution.|
|05-22-2008 03:58 PM|
Very true for most. I went through a 2 1/2 month school while in the CG to learn NASA grade standards for soldering. I do understand that it is not for most people. I do believe I still have the coarse material for the class that I took if anyone is interested in it. I have seen the downsides and upsides to both methods. There are lots of great products out there to choose from, it is just a persons opinion of what they are most comfortable in using. For a lot of people its a trial and error with the hopes of there being very little error. If one is to use a mechanical crimper there are some pretty sweet racheting crimpers out there that are easy to squeeze and apply the proper pressure for the size of wire and connector. I guess what I am trying to say is that for DIY people they should do what they are most comfortable with and if it is a project that they aren't comfortable hire a skilled trades person. I like the board and there is a lot of useful information on it. The last thing I want to do is step on anyones toes or beat a beaten to death subject anymore.
|05-22-2008 03:39 PM|
Soldering connections on a boat is generally not wise. ABYC guidelines recommend mechanically crimped connections, and we've beaten that particular subject to death a few times. Soldered connections are more difficult to make than a proper crimped connection for many people, and the soldered wire tends to be subject to work hardening and fatigue, unlike a crimped connection, and generally experiences more corrosion problems due to the dissimilar metals.
|05-22-2008 03:32 PM|
|Islander30Bahama||I have been an electricain now for almost ten years. I started as an electrician mate in the USCG. My current job as a Service Advisor for a mobile document destruction equipment company I work with all kinds of relays. Both in the Coast Guard and my current job I have seen great ways and terrible ways of preventing corrosion. If your lights draw 15 amps then use a relay rated for at least 25-30. They will still use the same base and pin layout but will not heat up as bad. I would only use hermaticaly sealed relays as well. Little bit more pricey but will hold up to the marine enviroment much better. If you plan on extending the wiring from the original point to a new switch in the cockpit make sure that the switch is rated for at least 25-30 amps to extend its life. In this very corrosive marine world di-electric grease can be a really good friend. I refuse to use any kind of female spade connector on a boat. A trick that I learned from an old Master Chief was strip the wire end about half of an inch, run this through the hole on the male prong coming off of the switch, twist it back onto to it self then solder it. before placing the wire on the switch place an inch and a half long piece of the appropiate sized self sealing heat shrink on the wire. When soldering always use a little heat sink to prevent the solder from wicking into the wire under the insulation. That is very import because over the course of its life vibration it can cause an open in the conductor under the insulation invisible to you. Making it impossible to find. When ever splicing wires together I always use a solderable butt connector using the heat sinks and I also alyways use a clear heat shrink so the connection is able to be inspected in case of a failure.|
|05-22-2008 02:48 PM|
I wish you hadn't told me that
I do plan to use a waterproof switch panel for the lights. I hadn't even thought about the engine panel not being waterproof, mine is very low in the cockpit and would definitely get wet with a wave coming in. That would be a big job to move I would imagine...
|05-22-2008 10:18 AM|
There are waterproof switch panels that would probably survive the cockpit being pooped.
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