Skip to main content ↑ ↓
Topic: Voltage Sensing Relay Install (Read 882 times) previous topic - next topic

Voltage Sensing Relay Install

  Since purchasing my coach I have a a problem with engine spinning slow if the coach set for 2wks or more.  Approx. 8 weeks ago I ordered a Voltage Sensing relay and cables from FOT.  I thought it would be a good alternative to a trickle charger.  The relay was an excellent addition.  The coach now turns over as it should.  I leave my coach plugged in and the relay now takes care of the batteries.
Jerry & Nanci
1999 U270 34'WTFI
2011 Malibu
A smart man knows what to say, a wise man knows when to say it.

Re: Voltage Sensing Relay Install

Reply #1 –
I installed this one, has ability for manual control as well Combiner 160 Sheet

Removed isolator.
1998 U270 34'

Re: Voltage Sensing Relay Install

Reply #2 –
Krush,
Yours closes at a lower voltage.  I did leave the isolator.  I haven't seen an issue.  Why did you remove the isolator?
Jerry & Nanci
1999 U270 34'WTFI
2011 Malibu
A smart man knows what to say, a wise man knows when to say it.

Re: Voltage Sensing Relay Install

Reply #3 –
I removed it for a couple reasons: the isolator isn't needed with the combiner; I'm not sure if the isolator even worked; the isolator, by it's design, sucks energy (reason for cooling fins); I used the space and the wires going (EDIT) to ISOLATOR to wire up the COMBINER; combiner has lifetime warranty.

The combiner works both ways: it charges engine batteries when from house charger, and it charges house batteries when engine is running. I hooked up a 3 position switch which allows OFF/Auto/On. The on function really isn't needed because we have a boost solenoid--but if that fails, it's another option (combiner won't pass the amount of amps a boost solenoid will, though).
1998 U270 34'

Re: Voltage Sensing Relay Install

Reply #4 –
Quote from: krush –
I used the space and the wires going to combiner to wire up the isolator.
To be clear did you mean" I used the space and the wires going to isolator to wire up the combiner "
The selected media item is not currently available.Barry BEAM #16014
2003 U320 40' AGDS
Beamalarm, Foretravel technical help and specifications
"Whatever the mind can conceive and believe, it can achieve"

Re: Voltage Sensing Relay Install

Reply #5 –
The Combiner claims to have no voltage drop.  The Isolator has a voltage drop of a diode (approx 0.7 volts).  To me this implies that converting from the Isolator to the Combiner would require adjusting the max voltage of the alternator.
Audrey & Harvey Nelson
2000 U-320, 40' towing 2014 Jeep Grand Cherokee
nelsonah@ieee.org

Re: Voltage Sensing Relay Install

Reply #6 –
Quote from: Barry Beam –
To be clear did you mean" I used the space and the wires going to isolator to wire up the combiner "

You are correct....dyslexia! I fixed the order.
1998 U270 34'

Re: Voltage Sensing Relay Install

Reply #7 –
Quote from: Harvey Nelson –
The Combiner claims to have no voltage drop.  The Isolator has a voltage drop of a diode (approx 0.7 volts).  To me this implies that converting from the Isolator to the Combiner would require adjusting the max voltage of the alternator.

Harvey,

If I understand your question correctly no you don't need to change the set point on your alternator voltage regulator.  The regulator will see that there is less residence in the line and will adjust the voltage to the set point.  You can look at it like this also, if you change the length of wire from the alternator to the battery from 10' to 100' the regulator sensing would change the output to maintain the set point.  If you change your battery type, that requires a different charge voltage set point, then yes (there are other variables too, this is just one) you would need to make a change.

Pamela & Mike
Pamela & Mike 97 U 320

"It's not what happens to you, but how you react to it that matters."

Re: Voltage Sensing Relay Install

Reply #8 –
I noticed the following in the 160 combiner manual:
Quote
3. Connect one high current terminal to the positive terminal of each battery bank. ..........IMPORTANT:- Use only 6 gauge cable or smaller. Use a minimum of 6 feet of wire total between the positive battery 2 terminals to connect the Combiner. It can be 3+3 feet or any combination for 6 feet or more. DO NOT use a heavier gauge (lower gauge #) wire.
.

Do I read this correctly that it prohibits connecting the heavy gauge battery cables directly to the combiner?

Re: Voltage Sensing Relay Install

Reply #9 –
Quote from: Bob McGee –
I noticed the following in the 160 combiner manual: .

Do I read this correctly that it prohibits connecting the heavy gauge battery cables directly to the combiner?

You read correctly. The combiner is not meant to be a heavy boost solenoid. It is made for 160amps.

The manual states the reason for the 6 feet of 6gauge wire is to provide enough resistance to prevent inrush current from burning up the relay. This could occur if one battery bank is dead and the other battery bank is fully charged. The 6gauge wire "dampens" the rush of current as the relay closes.
1998 U270 34'

Re: Voltage Sensing Relay Install

Reply #10 –
Would appear a heavier contactor might be in order.  Would think these fragile items seem to have a reliability issue over time ?
IF I had in mind to play this game, would be thinking about an oil pressure switch to pull up a proper contactor, when engine is running, it conducts, when stopped, it opens contact.

Re: Voltage Sensing Relay Install

Reply #11 –
Considering they offer a LIFETIME warranty with the only stipulation being that the proper sized wire be used, I'd say the designers probably have it figured out.
1998 U270 34'

Re: Voltage Sensing Relay Install

Reply #12 –
While I installed the VSR I did not remove the Isolator.  I do not expect an issue, but if it did fail, worse case scenario turn boost solenoid on start coach replace VSR at earliest opportunity.
Jerry & Nanci
1999 U270 34'WTFI
2011 Malibu
A smart man knows what to say, a wise man knows when to say it.
 

Re: Voltage Sensing Relay Install

Reply #13 –
I'll add another reason I removed the isolator. I have no way easily monitor if it is isolating properly. I don't want to end up with a surprise and have dead engine batteries.
1998 U270 34'