[Jim]

Great news, Tom! And thanks for the fridge plug tip. Excellent! Now get back to GA or FL and ‘chill’.

[Archived]

Marathon advised me to unhook the inverter temp sensors a few years ago when my inverters would act up during cold weather months. I am sorry I did not think to mention that earlier.

[Jeff]

I’m not comfortable with disconnecting temperature sensors.

Inverters did not always have sensors, but they were added by inverter manufacturers as a means to enable the inverter to adjust charging voltage based on temperature.

As temperatures rise, charging voltage has to go down. Battery manufacturers often make available temperature / voltage curves so battery owners can be aware of the need to adjust. Back in the olden days before sensors charging voltages had to be manually adjusted if batteries were going to go from one temperature extreme to the other.

If our bus house batteries are in a relatively constant ambient temperature we can get away with eliminating temperature sensors. But if a coach is used to go to ski resorts and sub zero temps and then to the desert southwest in August charging at a constant voltage could damage the batteries.

If I interpret what has been posted, temperature sensor are not the problem, but faulty connections of the sensors seems to be the issue. Perhaps the real solution is to keep the electrical connections corrosion free, and retain the sensors.

[DON]

Temp sensors were not designed for the best with every battery application….It was designed as a safety backup for the charge.. With our coach setup cold weather or hot then your batteries may never see a full charge. Unplug them

[Art]

We will have to disagree on this issue.

While a temperature sensor being used with inverters may be a pain in the ass as far as having the potential to create a problem both inverter manufacturers and battery manufacturers are consistent in recognizing the benefits.

From Lifeline’s Battery manual they list the charging voltages at specific temperatures. At a reasonable temperature range we are all likely to experience the spread between the voltages and it is substantial. At 30 degrees to fully charge you need 15.1 volts (30.2 @ 24V) and at 80 degrees you need 14.27 volts (28.54 @ 24V). If you are charging your batteries at 100 degrees the voltage drops to 144 (288 @ 24V).

Float voltages have a similar spread. What does this variation mean? Pick a charging voltage for charging without a sensor and in some cases the battery is not getting fully charged, sulfating the plates and shortening the life of the battery, or in some cases you can be over charging, also shortening the life of the batteries.

If you have greater spreads between your hot and cold battery temperatures instead of the likely unrealistic spread I chose for the example the problem becomes greater. If you do choose to disable or disconnect the temperature sensor make sure you adjust the charging voltages for absorb and float to those specified by the battery manufacturer to reflect the likely temps where the coach is going to be located.

If you have gel cell batteries be especially aware of hot temperature charging settings because gel cell batteries are very intolerant of excess charging voltages.

[Archived]

Proof in the pudding…I have seen a lot of issues with temp sensors….Do not see issues without them….think of all the coaches with Freedom 25 units that never had them…no one had issues with batteries due to the lack of temp sensors….

[Corey]

I cannot disagree with what you say, and the only way to determine if temperature sensors are really a value or detriment is to get statistics to prove coaches with them have longer battery life or less trouble with batteries than those without them.

[Archived]

Tom, or anyone, I can not find anything in the Trace or marathon Manuel that describes what happens when a inverter is “bypassed” or when that is best solution?

I have lost ac-1 input for some reason, happened few days ago but cycling the inverter off and on it came back.

I have checked the voltage path from pedestal to main junction to inverter breaker panel and it is all good. there is a red light on one of the relays has a “red” light it is labeled “RIP INVERTER LOSS”?

I don’t know if “bypass” would temporarily solve the problem.

I ha hoped to get educated at the seminar that I missed last year.

Hope to make the next.

[Dan]

When we discuss inverters and “by-passing” the term is meant to send electric current from a power source such as shore or generator power direct to the 120V breaker panel and the device or appliance without passing through an inverter.

Under ordinary circumstances if shore or generator power is available an inverter sees that power and does two things. It passes that power through the inverter directly to the 120V breaker panel, while at the same time using some of it to switch the inverter into a battery charger.

But if an inverter has failed and does not pass electrical current through to the circuits it powers, then the only way to power those circuits is to completely go around or by-pass the inverter.

[Archived]

Thanks Jon, I guess I knew the definition of bypass, I should have said , when I bypass , and shut down the generator , will I still see the line voltage on the display? and do I need to do anything else?

Jim

[Shelly]

Might be worth noting that the newer Magnum 4024 inverters have an internal automatic transfer switch.

When AC power is sensed from either shore power or the generator, the inverter goes into “stand-by” mode with the internal transfer switch sending power directly through the inverter.

Most Magnum arrangements do not have an external bypass switch.

[Art]

[Liam]

Jim,

I’m comfortable talking about Liberty conversions and any other conversions are not in my wheelhouse. I am guessing however that if you do not have shore or generator power and the inverter is not “on” you shouldn’t see any readout on your panel.

[Archived]

Jim,

I’m confused as to your question about line voltage when on bypass. There will be no voltage on the remote if gen or shore is removed. You won’t be inverting.