Head Scratcher - 40A+ draw from the fridge?

[Leeski_Clan]

Hi Forums,

I installed a GoPower IC 3000 which is an inverter, charger and transfer switch combo unit.

In testing, I first ran the TV which pulled ~1.5 A. Then I ran the Norcold 2118 refrigerator and according to the GoPower monitor, the Amp draw went from 1.5A to 48A! I let it run for about 5 minutes and it was defiantly killing the battery bank. The fuse panel is on the same circuit as the fire place but the fireplace was off.

Any idea what would eat that many Amps?

Larry

[dougrainer]

Lets make it REAL simple. The 5 amp fuse on the Norcold board for the 120 element would BLOW if you had a AC amp draw that high. Your high amp draw is DC amps. You are confused about which is which. Doug

[Bobbo]

Leeski Clan wrote:
Oh, so it is normal to draw that much? The Norcold site says 6Amps.
Norcold 2118

Let's do a little math. Norcold says the fridge pulls 6 amps. That is 120v AC. Six amps 120v AC is 720 watts. Now, you are pulling those watts from your battery bank to feed the inverter. To get 720 watts from the 12v battery takes 60 amps of 12v power. Considering the inverter is probably only about 80% efficient, that 60 amps actually becomes about 75 amps.

So, if you are measuring the 12v draw from the batteries and only reading 48 amps being pulled, you are actually doing very good.

The whole point of this is, don't run the fridge on the inverter. If you don't have 120v power to plug in to, run the fridge on gas.

[time2roll]

I ran mine twice on electric (about 6 hours) when the propane did not fire when we were ready to hit the road. Fixed the propane at the destination.

[2oldman]

It should defiantly draw at least 30a.

[mchero]

I never run our norcold off the inverter!
too much draw on those house batteries!

[garyemunson]

The 6 amps is the 120 volt AC value. Your inverter needs A LOT more amps than that at 12 volts DC to provide the 120 volts/6 amps A/C. Just like Leeski posted! Use the inverter to power the fridge when you are driving (engine will keep batteries charged) but as soon as you park, if you are not going to plug into shore power, switch to propane and save your batteries.

[Harvard]

Leeski Clan wrote:

turbojimmy wrote:

Harvard wrote:
40 Amps at 12 VDC = 480 watts OR 4 Amps at 120VAC = 480 watts....could be true...

Yeah that's about right for a 120V heating element. Mine says it's 300 watts but I never checked the actual draw on it.

Oh, so it is normal to draw that much? The Norcold site says 6Amps.
Norcold 2118

Let it be known, electrical has been my Achilles heal ever since I blew up my lamp in Grade 7 shop class. I don't understand it well. Amps vs Watts vs Volts sounds like Charlie Browns teacher to me. 🙂

Yes, the Norcold spec is 6.61A at 120VAC which is 790 watts. That load at 12 VDC would be 790W / 12V = 66 DC Amps

[time2roll]

I have a label at my inverter remote to switch fridge to propane only.
Truth is I about always run my fridge on propane anyway.

[wa8yxm]

That shounds about right for a RV fridge on electric,, That's why they don't put the `12 volt option on 'em any more

Fridge draws about 350-450 watts depending on model on AC.

[MrWizard]

absorption fridge, run on heat, either a LP 'flame' or electrical 'heating element'

that web page says either 5amps at 120v aka 600watts, or 6.61amps at 120v aka 793watts, for the (2) versions of the 2118 fridge

as you found out, it takes a large 45+ amp draw (at 12v) to power the inverter for 600w to operate the fridge

it appears there is nothing wrong with your fridge, that is normal power for that fridge

i suggest you put it on LP and leave it there

[ktmrfs]

Leeski Clan wrote:

turbojimmy wrote:

Harvard wrote:
40 Amps at 12 VDC = 480 watts OR 4 Amps at 120VAC = 480 watts....could be true...

Yeah that's about right for a 120V heating element. Mine says it's 300 watts but I never checked the actual draw on it.

Oh, so it is normal to draw that much? The Norcold site says 6Amps.
Norcold 2118

Let it be known, electrical has been my Achilles heal ever since I blew up my lamp in Grade 7 shop class. I don't understand it well. Amps vs Watts vs Volts sounds like Charlie Browns teacher to me. 🙂

6A on 120V is going to be 75+ A on 12V.

[ktmrfs]

Leeski Clan wrote:
Hi Forums,

I installed a GoPower IC 3000 which is an inverter, charger and transfer switch combo unit.

In testing, I first ran the TV which pulled ~1.5 A. Then I ran the Norcold 2118 refrigerator and according to the GoPower monitor, the Amp draw went from 1.5A to 48A! I let it run for about 5 minutes and it was defiantly killing the battery bank. The fuse panel is on the same circuit as the fire place but the fireplace was off.

Any idea what would eat that many Amps?

Larry

yes, the fridge operation on 120V element. OK the element is going to draw about 3-4A on 120V, translate that to running from the battery bank and the draw is going to be 35-45A or so from the battery bank.

take the 120V Amp draw and mulitply by 12 or so to get battery draw given inverter efficiency etc.

[BFL13]

Leeski Clan wrote:

time2roll wrote:
I call normal for an absorption fridge. Set the fridge to propane only while using the inverter. Or is this a compressor fridge?
Actually mine draws about 30 amps so I assume yours has more features. You want to see some real amps... put the water heater on 😉

I would recommend 600+ amp hours battery for a 3000 watt inverted.

This is a propane electrical fridge. Norcold 2118.
I have 4 x 6v @ 210 Ah each so I have 800+ Ah.

Two 6s in series make 210 and another pair in parallel with them makes for 420AH.

[time2roll]

Actually 420 at 12 volts. Same as me running a 2000 watt inverter. Just beware of the limitations as you know the battery can be discharged very quickly if you are unaware of what is on.