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VetteLT193
01-24-2009, 10:30 AM
What are the specs, or what do you run, for your Bennett trim tab pump power line?

The wire on mine is too short so I want to replace it. It seems really beefy for the pump, not as big as a starter cable but almost that size. I don't have wire on hand nearly that large and the other wires on the unit itself are not that big so I'm wondering if the previous owner just used something he had laying around.

Thanks!

gcarter
01-24-2009, 10:36 AM
Call Bennett. They offer a twisted wiring harness about 25' long. Ya can't beat it.

VetteLT193
01-24-2009, 10:46 AM
Call Bennett. They offer a twisted wiring harness about 25' long. Ya can't beat it.

You are talking about the one that goes to the switches, correct? The power line is a separate wire the way my boat is now... is factory bennett all one unit? I'm only talking about the power line. Mine was hooked directly to the battery, actually daisy chained through the starter (yeah, don't ask, I'll never figure out what the previous owner was thinking). I'm going to add a 2nd battery and switch so I need that power wire to be much longer than the foot or so it is now.

BigGrizzly
01-24-2009, 12:12 PM
Vett, you will find that that wire is a 10 gage with a fat insulation. The Bennett The motor on that pump isn't that strong. Your starter cable must be a thin jacket 2 or 4 gauge, depending on length. My Corsican had what i consider small wire in the harness so I rewired the whole boat. It had as small as 22 gauge in some places. I am not sure it was worth it because our 16 is all original except for the engine and never been restored, and it works Oksince 1966. It just made me feel better.:).

gcarter
01-24-2009, 01:29 PM
Well, there's the one in the Minx.....this was a stock Bennett piece. Brand new pump, fittings, and wiring harness throuigh their "exchange" program. The bullet connector is the ground. Couldn't be more than 12 ga. I either installed a Molex connector, or it came w/one.....except for the ground. You can see I grounded it on the drive trim pump.
The power came from the dash.......with its own fuse, nowhere else.

http://www.donzi.net/forums/attachment.php?attachmentid=7139&d=1098119144

VetteLT193
01-24-2009, 02:10 PM
Griz, the 10 gauge makes sense, I'll get new stuff.

Gcarter, that is what mine looks like too. It just looks so fat, so it all makes sense based on the thick insulation Griz referred to.

Getting there... one wire at a time. If it stops raining I should be able to get the dash in and all the standard gauges wired up, along with the new battery switch and be almost good to run by the end of the weekend.

Exhaust is the last big item to get worked out so I can run again. A bunch of other goodies I can do after I run it a couple times with the old configuration.

BigGrizzly
01-25-2009, 08:40 AM
Vett, I was in in the garage screwing around making and fixing anything and everything, so I climbed into the empty engine bay and measured the power wire. It is in fact a fat 12 Ga wire. I used my new current draw meter to dheck it out and The pump doesn't draw enough power even when dead headded to warrant 10Ga. However as usual I over engineered a crow bar and put 10Ga in the the other boat the Corsican. This boat is the Criterion and is original as far as the Bennett system is concerned. 28 years old and not a problem:yes::yes:

DickB
02-06-2009, 06:21 AM
Call or email Bennett. Bennett has one of if not the best customer support of any company with which I have dealt. I have emailed their tech support a couple of times – in fact earlier this week with a related question – and got a response within a couple of hours.

That said, this is one of those questions to which there is no single or right answer (although there are certainly wrong answers). The big factors are the length of the wire and the current requirements. The Bennett pump is fused at 20 amps, and Bennett confirmed to me that tab switches for their system should be rated to 20 amps. I would use that number for wire size also rather than measured current draw as a design point. There are tables where you can look up the current-carrying capacity for a given wire length and gauge. Here are some references:

http://www.powerstream.com/Wire_Size.htm
http://www.engineeringtoolbox.com/amps-wire-gauge-d_730.html (http://www.engineeringtoolbox.com/amps-wire-gauge-d_730.html)

The second table appears to be more conservative than the first, taking into account the fact that 12v wiring in a vehicle is likely to be bundled. A sometimes-overlooked consideration is that current-carrying wires dissipate heat. A wire buried in a bundle can dissipate less heat than one in free air, so the capacity of a bundled wire needs to be downgraded. Based on the lengths likely to be encountered in our boats, from the tables I would say 10 gauge would be more than adequate and 12 gauge could also work. With cost and ease of installation negligible factors in this case, it never hurts to go larger.

VetteLT193
02-06-2009, 07:07 AM
Vett, I was in in the garage screwing around making and fixing anything and everything, so I climbed into the empty engine bay and measured the power wire. It is in fact a fat 12 Ga wire. I used my new current draw meter to dheck it out and The pump doesn't draw enough power even when dead headded to warrant 10Ga. However as usual I over engineered a crow bar and put 10Ga in the the other boat the Corsican. This boat is the Criterion and is original as far as the Bennett system is concerned. 28 years old and not a problem:yes::yes:

Thanks Grizz. I haven't dropped a new wire in so that will help.

It has been freezing up here and I'm waiting on parts to come in the mail. Boat is going to be side tracked for another couple of weeks because I have to store it during my trip to the Keys for the boat show run. It's slow going but worth it.

BigGrizzly
02-06-2009, 08:45 AM
Dick B, good customer support-- THAT IS A FACT, no fiction here. They stood behind every issue they have had. Could this be why they are the biggest tab company. I have a 28 year old system in the Corsican, the only trouble it has had I caused.