Adding a new DC Fridge during a LA Heatwave

[booster]

Originally Posted by themexicandoctor

I tried with my voltmeter inserting the probes into the back of the fridge at the module but couldn't get the probes in to get a reading - my RV Guy said the only way to do this was the Clampmeter which was only reading 2.1 versus 2.2amps.

Is there a better way, could I have put the probes right into where the 12 volt wire connections were wire in plugs & wrapped?

Or most likely, was it an intermittent issue, with the connection - I didn't get under the rig when he found the issue to check, I just trusted him 100%.

I will get photos next week & a better answer but it appeared to be under the rig, driver's side, where the underneath connections for the shunt (?) were.

If you have a link to understand the process I do have a voltmeter.

Are you saying the shunt is hanging under the van? in the open?

[themexicandoctor]

Originally Posted by booster

Are you saying the shunt is hanging under the van? in the open?

I never went under there this time.

It do know its in the location where the 12 volt cables travel from the passenger side & meet somewhere below the shunt/electrical/box area.

I guess, based on the Versatile only layout that all the IN THE VAN electrical connections occurred at the box, behind the stove, under the trap door, below where the TV hung - these connections were deep underneath this ON THE OUTSIDE.

[GeorgeRa]

Originally Posted by themexicandoctor

I tried with my voltmeter inserting the probes into the back of the fridge at the module but couldn't get the probes in to get a reading - my RV Guy said the only way to do this was the Clampmeter which was only reading 2.1 versus 2.2amps.

Is there a better way, could I have put the probes right into where the 12 volt wire connections were wire in plugs & wrapped?

Or most likely, was it an intermittent issue, with the connection - I didn't get under the rig when he found the issue to check, I just trusted him 100%.

I will get photos next week & a better answer but it appeared to be under the rig, driver's side, where the underneath connections for the shunt (?) were.

If you have a link to understand the process I do have a voltmeter.

Clampmeters are used to measure current, units are Amps. Voltage is measured between Plus and Minus, sometimes red and black wires, sometimes between red wire and a ground, units are Volts. If you had issue with ground connection just measure Plus and Minus at the fridge, see the picture.

[avanti]

Originally Posted by GeorgeRa

Clampmeters are used to measure current, units are Amps. Voltage is measured between Plus and Minus, sometimes red and black wires, sometimes between red wire and a ground, units are Volts. If you had issue with ground connection just measure Plus and Minus at the fridge, see the picture.

Just to add to the confusion:
It would also be useful to measure the RESISTANCE (measured in OHMS) between the wire feeding the topmost connection in the illustration that George posted and the negative battery terminal. This value should be very close to zero. If it is significantly higher, it indicates a ground problem.

Once you can give a coherent rendition of ohm's law (which defines the relationship among volts, ohms, and amps), you get the first gold star to proudly display on your RV Junior Electrician's badge.

[themexicandoctor]

Gentlemen Thank You,

Keep the sarcasm coming, I deserve it.

Believe it or not, thst is where i tried to get the probes because they were so clearly marked but i couldn't get them deep enough - give me 24 hours.

[avanti]

Originally Posted by themexicandoctor

Keep the sarcasm coming, I deserve it.

Just for the record, when I use the "wink" emoticon, I intend it to mark good-natured banter, NOT sarcasm. You are doing great.

[@Michael]

Originally Posted by themexicandoctor

Gentlemen Thank You,

Keep the sarcasm coming, I deserve it.

Believe it or not, thst is where i tried to get the probes because they were so clearly marked but i couldn't get them deep enough - give me 24 hours.

Yep - you are doing great.

To know if resistance is a problem you have to measure voltage when the fridge compressor is running.

Getting that is a pain - It's hard to get a volt meter on the tabs where George pointed out. The connectors are insulated, so there is no room to jam voltmeter probes against the connectors, and poking around too much might short the +12v to ground.

I did this on mine. Had to figure out how to expose enough of the spade connector without disconnecting the fridge. The spade connectors that were very tight on the lugs.

But -- If it were me, and my fridge was cooling as good as yours is now, I would not worry about measuring the voltage at the pins.

[themexicandoctor]

Originally Posted by @Michael

To know if resistance is a problem you have to measure voltage when the fridge compressor is running.

Getting that is a pain - It's hard to get a volt meter on the tabs where George pointed out. The connectors are insulated, so there is no room to jam voltmeter probes against the connectors, and poking around too much might short the +12v to ground.

I did this on mine. Had to figure out how to expose enough of the spade connector without disconnecting the fridge. The spade connectors that were very tight on the lugs.

Michael,

Thank you!

You probably saved me a lot of money while I was focused on getting my first Gold Star

I certainly tried & couldn't get a reading - next week when I see my RV guy again I will ask him.

[avanti]

I agree that if everything is working, this is mostly academic. But, for future reference, here are some tricks for getting measurements in the situation you faced:

1) Build a couple of these (parts available at auto-parts store):

Obviously you need one male and one female spade connector.

2) Buy a couple of these:


3) Believe it or not: Stick a thin straight pin through the boot or even the insulation of the wire. This is an old pro-trick for measuring a wire where there is no connection available.

[tgregg]

Originally Posted by themexicandoctor

An average* of 34-38°F,Night/Day.

Have ever got the refrigerator to maintain a constant 34-38°F for more than one day?

[mkguitar]

Originally Posted by avanti

3) Believe it or not: Stick a thin straight pin through the boot or even the insulation of the wire. This is an old pro-trick for measuring a wire where there is no connection available.

many probes are made sharp enough to push through when you need a measurement and will then tape or other wise seal over your pinhole
mike

[themexicandoctor]

Originally Posted by avanti

I agree that if everything is working, this is mostly academic. But, for future reference, here are some tricks for getting measurements in the situation you faced:

1) Build a couple of these (parts available at auto-parts store):

Obviously you need one male and one female spade connector.

2) Buy a couple of these:


3) Believe it or not: Stick a thin straight pin through the boot or even the insulation of the wire. This is an old pro-trick for measuring a wire where there is no connection available.

Will get the RV Guy to rig it up next week, Thank You

[themexicandoctor]

Originally Posted by tgregg

Have ever got the refrigerator to maintain a constant 34-38°F for more than one day?

Gregg,

The whole problem was MY LOOSE NEGATIVE GROUND (?) connection.

Found by my RV guy when he was studying how to do the battey box change which is postponed to next week.

For the last 3 days my average has been 34%.

Will include a couple of graphs.

Got to love Sensorpush Bluetooth.

Note; the 46° spike was causing by my turning the fridge off for a couple of hours.

I have been driving around FAT, DUMB & HAPPY for over a year, maybe more.

You see I had no heavy usage, certainly nothing like a fridge & I only installed Solar about 21 months ago.

I love my Novakool.

And even thought it was running 2.1amps on the Clampmeter when tested, the issue was probably intermittent.

Moreover, the huge reduction of my nightly draw after Solar has signed off & I have stopped driving was evident last night when for 12 hours, my fridge only used approximately 14amps & by 10am my 250 watts of solar had my batteries back to 100%.

This was what I was looking for, the Fridge being able to cycle on & then off whereas before it was running 24/7 for 4 weeks.

[themexicandoctor]

The Novakool is running like a Dream.

VIP with MY Electrical issue fixed, the fridge is cycling on & off, as it should & my amp hour draw has dropprd by more than 50%.

And the temperature is a steady average of 28°F with the Frony of the Cab at highs up to 117° & the rear Lounge, up 10 102°.

Oscillating between 22 & 33°.

I am ecstatic.

[themexicandoctor]

Here is the latest, its 112% in the front of my cab, 6 feet away or less its 24.4°F in my FRIDGE & has stayed with 0.2 of a degree for two hours

And its 11.0° in my FREEZER & has stayed within 0.2 of a degree for two hours.

Note; the freezer is listed as DRIVERS SEAT

[themexicandoctor]

Here is the data

[themexicandoctor]

Maybe this is the issue some posters have had with my thread, I believe that 11°F is actually -11.67°C

Or maybe I have this wrong?

[themexicandoctor]

These are my latest figures;

The Freezer* is averaging 18°F or -7.777 in Celsius.

*the freezer is marked Drivers Deat.

This is in a 24h Hour Range of Front Cab temps from 118-60°F, the Fridge with Rear Lounge temps from 109-66°F.

The Fridge which also controls the Freezer is set at 3.75 on 1-7 analog knob is averaging 28°F or -2.222 in Celsius.

[themexicandoctor]

And Battery consumption is way down, more than 50% less.

By 10am, with 250 watts of Solar, with no driving, I am already charged to 100% SOC.

[tgregg]

Originally Posted by themexicandoctor

These are my latest figures;

The Freezer* is averaging 18°F or -7.777 in Celsius.

*the freezer is marked Drivers Deat.

This is in a 24h Hour Range of Front Cab temps from 118-60°F, the Fridge with Rear Lounge temps from 109-66°F.

The Fridge which also controls the Freezer is set at 3.75 on 1-7 analog knob is averaging 28°F or -2.222 in Celsius.

TMD,

Could you post the screen shots that show the 24 hour temperature graphs for the freezer and refrigerator?

Thanks