LVD Alarm and red indicator light not operating

[chin_k]

You never can have enough screwdrivers! At least the Robertson screws does not strips like the Philips head, so that is a good thing.

[ski2ways]

You never can have enough screwdrivers!

Chin_k

You got that right; as my wife often tells me “A man cannot be too good looking, or too well equipped”. Of course, she is referring to my vast array of tools.

I finally was able to remove the couch panel and get better access to the LVD. I first found that the grey wire was loose in the spade terminal connector; it came out of the crimp. So, I replaced the connector and reconnected the wire to the LVD, and plugged in the shore power – fingers crossed. No such luck, still no red light and alarm. Ok, unplugged the shore power and I disconnected the grey wire and connected it to the white wire connection on the LVD. I turned on the couch batteries, and as you told me, the alarm went off and the red light turned on!

So, back to square one. I think my problem is inside the LVD. But I got the Battery Fail Safe alarm in the mail today. See the attached photo. Can I simply connect its red wire to the red sense wire on the LVD and its black wire to the white terminal of the LVD? Otherwise, I’d have to run the wires down to the battery, which I could probably do.

I can set the new alarm to the same set point of the LVD – 11.8 volts.

I am now afraid that the LVD will not sound its alarm...

Regards,

Jon

[chin_k]

Jon:
11.8 is a good setpoint, but I would be more comfortable with something higher, like 12.00 or 12.20. If it has too may alarm going off, I can always lower it later rather than having to deal with deteriorated batteries.

With your battery safe alarm, I think you will be all set. The good thing about the LVD is that not only it alarms you, but it also disconnect your power. You will need to get the optional switching relay if you want that function on your new gadget.

For fun, do you want to measure the voltage between the gray terminal (with the alarm and LED disconnected) and the V-out with the battery switch on both ON and STORE position? Do this with and without the shore power, so you have 4 different numbers. I will try to get the same numbers and see if we match. (Clay already post a table with two of the four numbers, and yours should match with the table there.)

[ski2ways]

For fun, do you want to measure the voltage between the gray terminal (with the alarm and LED disconnected) and the V-out with the battery switch on both ON and STORE position? Do this with and without the shore power, so you have 4 different numbers. I will try to get the same numbers and see if we match. (Clay already post a table with two of the four numbers, and yours should match with the table there.)

Ok, but I'm not sure what you mean by "with the alarm and LED disconnected" Also, the table Clay posted has a connection "Alarm post to ground post". The alarm post is the gray wire, which is negative - they must mean the alarm post to Vout, correct?

Sorry, I really am lame about electricity, but I do know how to build computers, having built 5 of them...

Jon

[chin_k]

Sorry, its my fault.

What I meant is to disconnect the gray wire, and test the LVD terminal where the gray wire used to be. The reason that you need to disconnect it is because the alarm and the LED may bleed voltage back, and it will confuse your valve with mine. I will have all the wires disconnected except for the V-in, white (ground), sense, and V-out.

Ideally, you want to contact the LVD manufactor for see how they test the LVD before they send it out to customer. If you want to do that, that will be even better than the reverse-engineering thing that we try to do here.

[ski2ways]

chin_k

Ok, here's my results:

1) I disconnected both the gray and the blue wires, as you indicated you would also do. Note that disconnecting the blue wire also disconnects the manual override, so the coach batteries light illuminated when I disconnected it.
2) I get no voltage read at all from testing voltage between the gray post with the Vout, 0.00 accross all four test points: Gray to Vout, Batteries on, Batteries store, shore power and batteries on and batteries store.

When I reconnect the blue wire, pushing to store turns off the batteries, BUT when I push on the green light does not illuminate! That scared me. So, I reconnected the gray wire and the batteries on switched to green, whew! It appears that, in order to turn the batteries on, the gray wire must not be disconnected.

So, my friend, what does all of this mean?

Jon

[Roly]

I eliminated the LVD, and replaced the battery combiner with a marine one, added bigger conductors, more fuses, and a 200 W solar system. This is somewhat what Blue documented herein elsewhere. I find it simplifies things, and makes for a more robust setup. There is more to be done when I get a roundtoit. The first diagram is solar system added before removing the LVD. Second is how the LVD was bypassed. I now have no overhead switching (My Premier did not have the overhead gen start switch connected anyway) My switches, cabin loads disconnect, and battery combiner override, are now behind the driver's seat at floor level, and batteries there, too, under the sofa,. The Bogart Industries battery monitor let me see what is charging or discharging and I can decide if the voltage is so low (12 vdc or less) as to disconnect, until the sun shines next...

Roly

[chin_k]

Jon:
I disconnected the LVD and tested the voltage. The result is very similar to the table that Clay linked in the reference section.

The main difference is that I have 0.32 V on the alarm (cf 11.80 on the reference doc) when I measured the potential. It means that the voltage is indeed from the alarm/LED that connected to the V-out. I got different voltage on the O/R (blue) wire too since I do not ground it like in the actual setup in the rig.

voltage related to ground when OFF:
V-in 12.47 (12.47 ON)
Sense 12.47 (12.47 ON)
O/R 5.23 (10.09 ON)
alarm 1.07 (0.32 ON)
V-out 0.00 (12.47 ON)

There is no difference when I connect both V-in to V-out (to simulate when the converter is on).

I may want to put a buzzer on the setup to hear the alarm, but I need to think more what to do to make it more helpful. One thing that I noticed is that to get the LVD to be OFF, I have to press down on the switch for a few seconds for it to work. I am using a momentary switch. In the Chinook, it has a regular switch on the OFF position.

[ski2ways]

Chin_k,

Well I guess I fried my LVD internal alert circuit to sound the alarm and LED, correct? I'm wondering if the LVD will disconnect when it is supposed to. I'm thinking about turning on the coach batteries and turn on fridg on DC, the new TV, radio, blu-ray player, stove lignts, fan, whatnot and watch my new voltage indicator display the voltage drop. I have set it to push an alarm at 12.00 volts - let's see if the LVD disconnects at 11.8 volts.

When the LVD disconnects the red light on it illuminates. I know that because that's what happened when the rodent bit off the Sense wire. That is what led me to look at the 15Amp breaker, only to see my real problem!

It looks like your LVD has been pulled. Did you yank it out like Blue and Roly above? How did you replace it? What they did appears to be my path as well.

Thanks again for all your help!

Jon

[chin_k]

You can use a potentimeter or just disconnect the red wire to the battery via the 15 A fuse if you want to see your LVD disconnect. I think yours is OK. The only thing that we are testing here, at least from my point of view, is to make sure it sound the alarm when the voltage is too low, or when you forget to turn it on when the converter is working.

I replaced my solar controller with one that has a load function and a low voltage protection, so I did not have to use it. I just finished with interface with the controller that allow me to use the existing wiring without too much modification to turn the load on and off. It is a bit of work to get everything working with the converter, solar controller, and the panel above the driver seat, so it is not really a drop-in thing if you only looking for a solar upgrade. I will make a post about it when I have time.

If your LVD is defective (I don't think so), I can send mine to you.