ginga said:
Seems like it might be simpler for me to use the 18awg AC cord the fridge came with. Would it not be wise to wire that AC cord to the fuse panel with a 15amp fuse? Or is it absolutely best to hardwire the fridge to the battery, because I'm not finding anything to wire up a 15amp fuse inline for 18awg wire.
Are you confused about the difference between AC and DC?
The AC cord is to plug into a regular 115vAC household outlet. There is no cutting it to hook it to 12vDC.
18 awg is more than adequate to power the fridge at 115 volts, but overwhelmingly inadequate at 11.5v DC.
The Lower the gauge number, the thicker the wire is. 12AWG is much thicker than 18AWG.
The 16awg DC cord is much thinner than Danfoss/Secop lists as acceptable. But in order to sell it as a portable 12v fridge, it HAS to come with a ciggy plug, and it is very difficult to hook 12 or 10AWg wire into a ciggy plug, and it is kind of pointless as the contacts in a ciggy plug and receptacle cannot handle the current that 10 or 12AWG wire can.
The 16 AWG and ciggy plug will work OK, while the battery is still fully charged, or when alternator is holding battery at charging voltages. But When battery is 50% depleted the voltage drop on the 16AWG abnd ciggy plug and receptacle could cause the compressor not to turn on. However the Fan will still turn on, make noise, and make the human listener think the fridge is still working properly, when it is not, due to the limited voltage because of the too thin copper and the resistance of the ciggy plug recpetacle and all the other connectors inline.
The whole Idea of cutting off the ciggy plug is to eliminate this inevitably troublesome connector, as they do wear out in time, and they do cause voltage drop, and they do wiggle their way loose. When loose and making marginal contact it is very hard on the compressor controller electronics as it is like flicking a lightswitch on and off a thousand times a second.
The 16 AWG directly to the Fuse block, and ground buss is Much much better, but 16 AWG is still dropping some voltage. It is less than Ideal. It will work though and will be many times more reliable than the ciggy plug/receptacle.
Now, the perfectionist might say screw the 16awg AND the ciggy plug. They might figure out which Pin on the 12v receptacle on fridge body is + and which is - and find a way to securely and safely connect 12awg wire right to these pins, then wire it right to fuse block and negative buss.
However, this might not be so easy to find the right socket to securely slide over the pins, and it could be knocked loose. One might realize this is yet another connector in the circuit, and each connector adds some resistance to the circuit. One might then decide why not just run power to the compressor controller itself.
Here is what my DC only compressor controller looks like on my upright frontloading compressor fridge:
See the two thicker red and black wires? These are the 10 AWG power feeds. Your AC/DC controller will have another connector on top for the 115VAC plug in.
In the pic above you can see that there is a small blue wire and a small brown wire going to the same terminal on the controller as the thick red and black wires. These are for the internal LED light. The 10AWG is crimped with a terminal like this:
and the smaller LED light wires are attached to the piggy back portion.
The true anally retentive perfectionist could wire 12 AWG or thicker right to the compresor controller itself so the fridge always gets maximum voltage and will keep running as long as possible as the battery gets overdepleted.
How far you want to take it is up to you. You will likely be fine just cutting the 16AWG cord and hooking it to the Fuseblock and ground buss. Do make sure you know which is + and which is -. Reversing the polarity might be fatal for the compressor controller at worst or require rewiring at best.
The spring loaded center pin on a ciggy plug is the (+). Using a digital multimeter set to ohms, place one probe on the spring loaded tip, and probe the two wires and see which one is the +. One wire will usually be smooth and the other has ridges on it. Usually, the ridged wire is +, but not always, so one HAS to test to make sure. Some red electrical tape on that wire or some red heatshrink prevents mistakes. Assume nothing.
Also a small nitpicking point, is that Ideally, the fridge would be wired directly to the battery, fused at the battery(+), rather than sharing the Fuseblock with other devices. The reason for this is not only for voltage drop, but that other devices hooked to fuse block or ground buss can send surges/voltage spikes through shared wiring, and the battery itself is kind of an electrical surge filter. The surges spikes can be cumulatively damaging to electronics inside the controller.
It is also best to twist the power leads between battery and the fridge to negate RFI entering and exiting the wiring. This wire twisting trick is also beneficial on circuits powering LED lights. RFI can knock out TV stations, and regulated LEDS are known sources of RFI. I had one LED bulb which would knock out a very strong TV station.
Keep in mind almost no Installs adhere to this small nitpicking point and still work properly for X amount of time.
Those of us with battery monitors might be able to wire and fuse the fridge right to battery (+), but the (-) has to go through the shunt for the shunt/monitor to be able to read the current for the fridge, and the shunt is a shared Buss that the directions say to avoid.
ANy wire connector adds resistance, and every crimp connector also introduces a possible failure point too. Newbs can easily screw up crimping, so be sure to pull on any crimped connectors with a good amount of force to insure that it is at least mechanically sound.
Anderson powerpoles come in 15, 30 and 45 amp sizes. but this only applys to the internal contacts and the wire sizes they are intended to be used with 15 and 30 amp powerpoles are easy to crimp and assemble, the 30 amp can just barely accept 12awg wire, but not 10AWG. 10AWG wire requires the 45 amp powerpoles and these are much harder to crimp properly without their special crimper. I'd say to focus on the 30 amp versions unless one buys the special crimper or is good with a crimper and what is required, then the 45s are preferable.
Once assembled, Anderson powerpoles in the 15/30 and 45 amp will All mate with each other.
They are a very reliable connector, but they have no fuse. If a 10 AWG 45 amp powerpole used as a DC output is fused at 30 amps, and one plugs a 15 amp powerpole into it with 18awg, well the 18 AWG would not be protected by the 30 amp fuse. One would need to reduce the fuse size for the thinnest wire on the circuit.
If using 10 or 12AWG wire, these Yellow Flag terminals can be installed inline on + power wire, and an ATC/ATO fuse inserted cleanly inline. Blue and red can be used inline on thinner wiring.
https://www.amazon.com/Nylon-Insula...rd_wg=5vGj0&psc=1&refRID=6KG9RVHNW57GQQ2K19R6
One could also just add a premade inline fuse to the powerpole connector and use a butt connector.
https://www.amazon.com/Quality-Spla...TF8&qid=1488406590&sr=1-8&keywords=12AWG+fuse
The fuse holder linked just above has two of the flag terminals inside the molded plastic which the fuse inserts into. I have found that they can be very poorly crimped and the fuse holder itself melts, which is why I posted the flag terminals themselves, as one who is good at crimping, can easily install their own fuse into wire with minimal extra connections required and minimal added bulk.
