Need an electrician

[jackelope]

I have a fairly urgent situation where a customer of ours needs a power inverter or 2 hooked up in a Ford Transit van. They need to power 2 refrigerators that draw 15 amps a piece. I’m surrounded by very skilled automotive technicians who are not electricians. Will one 3000 watt inverter power 2 of these fridges or should I get 2 that are 2k watts a piece or will it just not work and the van will burst into flames or ...

Anybody?

[ctwiggs1]

Comes down to watts.  Volts x Amps = watts.  So if it’s 120v x 15a x 2 reefers you’re at 3600 watts.

Assuming the fridges are 120v

[jackelope]

Comes down to watts.  Volts x Amps = watts.  So if it’s 120v x 15a x 2 reefers you’re at 3600 watts.

Assuming the fridges are 120v

I’m not positive that it’s that simple. Really I don’t trust myself that it’s that simple.

[jackelope]

We can do multiple inverters if the van will power them through it’s normal charging system. Cost isn’t really a factor.

Time frame is the biggest factor. It has to happen tomorrow. I can get a couple 3k watt inverters and hook them up if the van will adequately power them.

[ctwiggs1]

Hold on using a lifeline and phoning a friend

@skillet

[NRA4LIFE]

Reversing what Curtis said, 3600W/12V=300 amps.  You need to have some pretty big wires going to those inverters.

[Magnum_Willys]

It is that simple.   Home breakers are typically 15 A which us why most space heaters, cooking appliances etc are rated at 1500 watts.   115V x 15 amps -1725 so theres your safety margin.

Likely the fridges normally could get by with 3000 watts but if both started under load at same time maybe you would need more power.  But you are gonna need a couple big  alternators!

I would just plug in or go propane like  RV

[CP]

I’m not an electrician, just an electrical engineer, but 15 amps is a hefty draw for a fridge.  I’m guessing that’s the surge and then it will drop to about a 3rd of that.  The high inductive load of a fridge surges for less than a second but then drops way down.  As others stated A*V = watts.  30amps for both fridges would be 3600 watts.  Make sure the inverter can take that surge and verify that we are talking surge here and not steady state.

For what its worth, I run a single fridge with a 1000-watt inverter, no problems.

[CP]

PS – It’s the batteries that will power the inverter, the charging system just has to keep the batteries charged.  There are going to be high currents but for a very short time.  Less than 1 second surge, then a few seconds to a couple minutes running steady state.  Most of the time a fridge draws zero amps unless you leave the door open.

[jackelope]

The rest of the story is that this is to transport a crap ton of covid vaccines.  And they sprung the need on me at about 5pm tonight. And it needs to be done tomorrow. I don’t know if it’s realistic. Stock van with factory charging system.

[highside74]

Dry Ice

[CP]

The rest of the story is that this is to transport a crap ton of covid vaccines.  And they sprung the need on me at about 5pm tonight. And it needs to be done tomorrow. I don’t know if it’s realistic. Stock van with factory charging system.

In that case use 2 3000w inverters.  Redundant circuits so if one fails the other isn't lost.  Plenty of battery, LiFePO4 batteries. 

[hogslayer]

I have a built in sub zero fridge at my house thats 48" wide and only draws 8 amps.  They will be listed as 15, but won't draw that much power.  Mini fridge is about 2-3 amps.  If they need to rent a refer truck let me know. 

[CP]

Seriously, this is doable.  Double up on the inverter, at least 2-100ah batteries in parallel for each, 3 would be better.  Lithium is best, but lead acid will work.  300ah of battery will run a freezer for days without a recharge.

[Magnum_Willys]

In that case go rent a genny on a trailer or stick a 4500 watt on your receiver hitch.