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Topic: Routing of Magnum ME-BMK wires (Read 588 times) previous topic - next topic

Routing of Magnum ME-BMK wires

Hi all.  Adding a Magnum ME-BMK battery monitor.  Looking through the forums I can't find any specific information on routing the sensor wires into the battery compartment.  Not easy access at all. Furthermore,  it looks like the battery cables and everything converges in the area behind the fiberglass distribution panel next to it. Maybe I can break out the battery cable and connect the shunt there, or is that too far away from batteries? 
(2002 U320)

Re: Routing of Magnum ME-BMK wires

Reply #1 –
 I installed my Magnum ME-BMK  right by the inverter and the Me Arc I installed where the old
monitor was and used one of the old control wires and everything worked.

Re: Routing of Magnum ME-BMK wires

Reply #2 –
Sorry I think the Magnum ME-BMK  is the other monitor like the ME ARC and you should be
able to use one of the old monitor cables if not you might be able to switch monitors.

Re: Routing of Magnum ME-BMK wires

Reply #3 –
The ME-BMK will monitor my house batteries with a shunt off of the negative terminal and powered by other wires to the battery.  These wires need to be routed into the closed battery compartment which looks like a pita.  There is a hole in the ceiling of that compartment where the battery cables come in but not obvious how to get to it.  Or, would it be acceptable to just connect it all at the distribution panel area?

Re: Routing of Magnum ME-BMK wires

Reply #4 –
Distance shouldn't matter that much for a shunt reading. You're only talking a few feet of run. The shunt just needs to be between the battery and the negative post to get an accurate reading.

On a separate note.. Is that where the batteries are on a 2002? It's bad enough trying to get the batteries out from the bay in a '99, can't imagine trying to pull them out while hunched over.

Re: Routing of Magnum ME-BMK wires

Reply #5 –
I don't see the problem.  Looking at the photos, I see large electric cables running from the inverter up and into the central utility bay.  From there some of them drop down into the battery bay, and some come out the other side of the utility bay into the 12 volt central distribution/breaker panel.  Any wiring required by the shunt should be able to follow the same route.  Seems simple...but of course I'm not there to see it in person.  When running new wires in these coaches, you sometimes need to get creative.

Re: Routing of Magnum ME-BMK wires

Reply #6 –
The shunt should be installed as close to the negative terminal as possible and before any other connections... or it won't be tracking the draw accurately.

Re: Routing of Magnum ME-BMK wires

Reply #7 –
Fortunately I didn't have to install the batteries and they're only a year old.  Pretty sure the batteries go straight to the distribution panel.  That area is busy with all the cables. Can't tell where the inverter cables go.  Maybe to the transfer switch and back to distribution panel.  This stuff is still new to me. 
  I'd love to drill a 1/2 inch hole through the bulkhead and into the upper battery compartment to run my wires with conduit.  Would be sealed afterwards.  Is that practical or reasonable,  or is that forbidden?

Re: Routing of Magnum ME-BMK wires

Reply #8 –
Quote from: AdventureSofie –
1.  Pretty sure the batteries go straight to the distribution panel.
2. Can't tell where the inverter cables go. 
3. I'd love to drill a 1/2 inch hole through the bulkhead and into the upper battery compartment to run my wires with conduit.  Would be sealed afterwards.  Is that practical or reasonable,  or is that forbidden?
1.  Look at the electric diagram linked below.  You will see how the stock inverter was connected to the house batteries.  The positive battery cable has an inline 350A fuse (located on the distribution panel).  The negative cable goes direct to the batteries.

https://www.foreforums.com/index.php?action=media;sa=media;in=3297

2.  The Magnum inverter should be connected the same way as the original inverter.  It may even BE the original factory inverter - I don't know what came on your coach.  The only thing different for the Magnum wiring is the shunt, which should as noted in previous replies above, be as close to the battery negative terminal as possible.  See Magnum wiring diagram linked below:

https://www.bluepacificsolar.com/picture_library/inverters/magnum-ms-series-installation.png

3.  Not forbidden.  Drilling through a bulkhead is no problem - I have done it several times.  As a rule, Foretravel does not "hide" any wires or hoses inside the bulkhead walls, so no worries there.  You do need to watch out for possible square steel tubing framework inside the walls.  You can use a simple magnetic stud finder to locate the steel tubing and avoid it with your hole saw.

Re: Routing of Magnum ME-BMK wires

Reply #9 –
I'll need to try to trace the cables again looking at the labels.  The batteries only have one cable on each end.  The positive must go to the fuse then to the ganged lug. The negative may also go to its granged lug.  I'm thinking now that the inverter connects at the two lugs.  Just need to do some more crawling around and trace the labels. 
Thanks for the insight on the bulkhead.  The are so many cables going through the same small spaces that it will be a challenge to route any more. The only current access to the battery compartment is a small hole in the top where the battery cables go in,  and I can't see how to get there just yet. 

Re: Routing of Magnum ME-BMK wires

Reply #10 –
Photo below shows the bulkhead wall construction on our '93 U280.  Newer models should be similar.  It is a sandwich type construction, with white fiberglass skin on both sides and blue foam in the middle.  The steel tubing frame members (where found) are encased in the blue foam.

Re: Routing of Magnum ME-BMK wires

Reply #11 –
Shunt can be installed anywhere as long as you know for sure ALL loads are on the opposite end of the shunt. Because the voltage drop across the shunt is so low, using TWISTED-PAIR wires from shunt to meter will improve accuracy.

Re: Routing of Magnum ME-BMK wires

Reply #12 –
Sorry I got confuse and the first post is right. I would mount the shunt between the fuse and
the battery cable and from ME-BMK and I ran the cable to the inverter but my inverter is the
2812.
 

Re: Routing of Magnum ME-BMK wires

Reply #13 –
Here is what I ended up doing. Used a nine inch long 4/0 cable to install the shunt on the driver side wall of battery box,  so I was directly off the battery. For all the sensor wires I drilled a 1/2" hole through the bulkhead and the side of the battery box on the passenger side for the most direct route.  I had to avoid the steel frame around the battery box opening.  I routed the BMK wires and rerouted the temperature probe cable using one 3/8" ID flex conduit.  Mounted the BMK module next to the inverter. A neat look with easy access to these components. Happy to see battery life and use now up in the coach.