Sure Power Isolator to Blue Sea 7622

CaptainVo · 03-12-2015, 12:30 PM

So Im planning on getting rid of the Surepower isolator, three prong unit tied directly to alternator, and putting in a Blue Sea 7622. The van is a 2002 e350 7.3 Quigley. I just installed solar and want everything to charge. The plan of action is this.

1. Remove isolator and splice the alternator wire back together.
2. Remove house battery charge wire running from the engine bay.
3. Run new charging wire from the van battery that is under the frame up to a Blue Sea unit and then to the house battery. Not sure what fuses and ratings are necessary for connecting the two batteries together though.
4. Ground the Blue Sea unit and cap unused remote wires. For now I won't be hooking up the engine start option.

I was just hoping someone out there could check my work and make sure I don't do anything to stupid.

**daveb** · 03-12-2015, 01:14 PM

If you plan to disable the start assist feature you can probably use the existing wire. The best choice would be to upgrade that wire to about a #4 size or larger especially if the batteries are located in front under the hood. Mine is not fused but I want the ability to jump start off my house batteries. There are some members who have installed fusing. You base that off the required load and the fusing curve. You want the fuse to blow before damage is done to the wire. The smaller the wire, the smaller the fuse must be but you need to factor in the amp draw running through the wire as well. Distance is also a factor. For common charging off your alternator the fuse can be rated much smaller that what #4 can pack. In that case you might cut in a 100A breaker rather than a large fuse. But if you plan to configure the 7622 to assist start, you'll have to look into a larger fuse. It all depends on what your alternator (correction-starter) draws at a cold startup. IMO the separator is not supposed to supply the full amount of current required to start the vehicle, rather used in an assist mode. If that were the case I would think the wire size would have to match or exceed the OEM battery cable size routed directly to the starting battery. The isolator wire circuit was not designed as a starting circuit...it's a charging circuit.
There are several wire calculators in the FAQ post in this section.
IMO, just plan for the future and pull in a good stout copper buss run like #2 from the battery or starter. Get a high amp fuse holder and install a smaller fuse. Then if you do need to jump you can install a larger fuse down the road.

CaptainVo · 03-12-2015, 01:23 PM

The battery I was thinking of connecting to is under the swing out doors and attached to the frame. Its only about 2 feet from the house battery location. I figured I would have to run wire into the cab and setup the Blue Sea under the eb50 bench seat.

boywonder · 03-12-2015, 02:00 PM

Quote:

Originally Posted by daveb

But if you plan to configure the 7622 to assist start, you'll have to look into a larger fuse. It all depends on what your alternator draws at a cold startup. IMO the separator is not supposed to supply the full amount of current required to start the vehicle, rather used in an assist mode.

Dave, I assuming that you mean "starter" not alternator.........

CaptainVo: The Blue Sea stuff has quite high momentary current ratings (like up to 500A/750A or so), perhaps not quite high enough to start a cold diesel.......I have 5.4L gasser

I used #2 battery cables and 150A blue sea circuit breakers on the battery cables between the batteries. My thoughts are that if I kill the van battery, I can connect the batteries together and wait 30 minutes or so before trying to crank.

CaptainVo · 03-12-2015, 06:58 PM

Thanks for the help guys, it's much appreciated.

**daveb** · 03-12-2015, 09:33 PM

Quote:

Originally Posted by boywonder

Dave, I assuming that you mean "starter" not alternator.........

Opps yeah. Was in a hurry. I hate that when I do that.

Ocsmb · 08-25-2016, 03:55 AM

Hey gang. I'm about to do this myself. Our setup is identical Vo.

Here's what lead me to this thread.
Battery light came on while driving, and eventually my van wouldn't start. Thought for sure it was the alternator so I had a DC Power 185A installed. Come to find out my Sure Power isolator was toast. Doh! A $60 part but I just spent $500 for the alternator. That never feels good.

Read up on that great thread about isolators and separators and decided the Blue Sea 7622 is for me. I like the ability of charging both house and van battery with shore and solar.

At any rate, any tips, tricks, pics for the proper removal of the Isolator and all of its components and install of your Blue Sea?

From the isolator what do I do with the alternator wire, battery junction wire and house battery wire?

Where did you install the 150A circuit breaker on the battery cables between the batteries ?

Wbp · 08-25-2016, 05:45 AM

I just installed a blue sea isolator in my setup. I installed fuses at both batteries to make sure your lines are protected from both direction. I used a weather protected holder Blue Sea fuse block that covers on them.
I did not hookup the start side but I did hookup the on off switch and I suggest you do hook that up to be able to manually connect and discount.
So far it is working perfect.

Scalf77 · 08-25-2016, 07:19 AM

If replacing an isolator (diode based) you need to put alternator to battery back as stock. So your alternator will go to your starting battery. The new Bluesea 7622 ACR will go between your starting battery and house battery. As said, the wire that is currently from the isolator to the house is most likely not large enough to handle the possible current capabilities of the 7622, so you should replace. I use bluesea MRBF terminal fusees at the starting battery and on the ACR side of that cable.
Here is a picture of a MRBF fuse on the starting battery.

I also use a MRBF fuse on the "B" terminal of the ACR which goes to the starting battery. The ACR is on the right. Where ever your current isolator cable connects to your house side would be where you connect the "A" terminal. You can switch the two terminals if it wires up easier. The two larger cables, one comes from the Inverter and it has a Class T fuse on the inverter side, the other was is from the house battery which has a Class T fuse

This picture may be more confusing as I have some other Bluesea switches for a battery disconnect and solar disconnect.

If you have a original SMB you most likely don't have a Fuse close to your Hosue Battery, but that would be a good thing to do also.This is what I did for that.

Class T fuse protecting the house battery.

Polycase ML-47F*1508 7.63 x 4.63 x 3.09 in. NEMA 4X/ IP66 rated for outdoor use
Polycase ML-47K 0.06 x 7.12 x 4.13 in. Mounting Panel
Polycase CG-17 Cable Gland

Blue Sea 5502 -Class T Fuse Block with Insulating Cover - 225 to 400A
Blue Sea 5118 -Class T fuse 250 amp

-greg

boywonder · 08-25-2016, 08:06 AM

I used one of these located as close as practicable to both the house batteries and the starting battery:

https://www.amazon.com/Bussmann-CB18.../dp/B001PT7XBE

I pop the lever on the one under the hood (as well as disconnect the starting battery and pull fuse #20 in my 2008) when removing/reinstalling the front seats to prevent an SRS dash light from illuminating. Handy and simple way to isolate the battery banks