Installing Powerline Isolators on Mercury 75HP

[limbwalker]

I have a 1998 75 Mercury outboard, on a 20' Lund Alaskan, and bought a Powerline Model 33-10 Isolator for another old Starcraft I own and never got around to installing it, but now want to put it into this Lund..the Isolator has 3 posts on top A1, B1 and B2, ....Installation Instructions say to pick up primary power from the "Regulator Junction Box" and run it to centre post A1 to feed isolator.....I haven't pulled the cowl off the motor yet to see where these Junction Box is or if this Yellow/gray wire is there in which they indicate is suppose to be there, but the instructions are not specific to this particular motor...

I'm wondering why I can't run the main heavy + Lead from the engine that would Normally go to the start battery, and run it to the Centre Tap (A1) of the isolator, then from B1 run a 10awg lead to the + of start battery, then from B2 of isolator to + of Aux battery....and then run the Main Negative lead from engine, to the negative post on start battery and run one from there to Negative of Aux battery.... Should that not do the same job ?? Thank you... I tried calling the phone number to Hehr Power Systems in Fort Worth Texas and there was no answer, so maybe they aren't in business any longer, I'm not certain...If you guys could help shed some light my way, I'd appreciate it, thank you..

 

[Faztbullet]

Re: Installing Powerline Isolators on Mercury 75HP

'm wondering why I can't run the main heavy + Lead from the engine that would Normally go to the start battery, and run it to the Centre Tap (A1) of the isolator, then from B1 run a 10awg lead to the + of start battery

Because there are diodes between A1 and B1 to prevent feed back.. see below for simple install. Dont expect alot of recharging if you run below 2500 rpm as its only putting out about 8 amps at this rpm and full 16amps at WOT.

 

[limbwalker]

Re: Installing Powerline Isolators on Mercury 75HP

Thanks Bullet for the reply...the way things are ran in the diagram you posted is what I was hoping to avoid, or at least I thought I wanted to avoid....reason being,, with say all accessories being ran off Aux batteries and them always needing charging, the power has to go through the start battery and always heating it up which I felt was uneccessary, basically cooking it when only the aux need it..why put juice thorugh the start plates when only aux batteries require power...i thought this is what an isolator is suppose to eliminate.. this is how many guys have their systems wired when using those switches which is the reason i went with isolator..

 

[Faztbullet]

Re: Installing Powerline Isolators on Mercury 75HP

Why put juice thorugh the start plates when only aux batteries require power...i thought this is what an isolator is suppose to eliminate..

Charging will go to the lowest resistance(discharged) battery first till all are of equal resistance. Below is how you would do the isolator you have but you can only recharge 1 aux battery and still the weakest battery in system will get the most chargeing till both are equalized....

 

[limbwalker]

Re: Installing Powerline Isolators on Mercury 75HP

So i need to find the Recifier wire to feed the Isolator...I've been reading the use of isolators is older technology for outboard use..instead guys are using and ACR (might have that wrong)

 

[limbwalker]

Re: Installing Powerline Isolators on Mercury 75HP

I spoke with the people at Hehr today and told them what i was trying to acheive and they told me that yes they do charge at about 1Volt lower that it sohlud BUT, if I pick up a hot wire coming off Stator which is Not Rectified and should be about 2 volts higher in AC and run that wire to the centre post on isolator then it will be rectified and distributed in DC Volts...Any idea of which of the 3 stator wires I need to splice into to feed isolator ??

 

[Chris1956]

Re: Installing Powerline Isolators on Mercury 75HP

Limb, Multiple posts with partial info do not help us to help you. If you connect one AC wire of the stator to the inverter, I believe you will only get a half-wave rectification. This gives 1/2 voltage and power. A Merc rectifier is a bridge of 4 diodes. Unless both of the stator wires are connected to an equivalent bridge in the isolator, you will only have half power. Since diodes can cost 1 volt each, having two full wave bridge rectifiers connected in series will cost 2 V, which is what I think the company was trying to say. Since I did not see the spec sheet, I do not know if the isolators are bridge rectifiers.