Nova Kool 7300 Refrigerator Operation, Tricks and Modifications
The Nova Kool 7300 is a 12-volt DC refrigerator freezer with two separate Danfoss compressors, one for the freezer (1.7 cu ft) and one for the refrigerator (6.8 cu ft), each drawing approximately 30 watts (2.5 amps) when running. There are two thermostats in the refrigerator section. The one at the bottom controls the freezer, and the other is near the top for the refrigerator. Compressors have an advantage over ammonia absorption systems in that they can be up to 30 degrees off-level, whereas absorption must be level to operate.
If you have only a few items to keep cool for a weekend getaway, the top refrigerator can be turned on while leaving the freezer turned off, saving some battery power.
The Nova Kool wiring diagram indicates there’s an option available to add a switch to turn the light off when storing with the door open. There are also connections for adding a circulation fan inside the refrigerator. I guess coach manufacturers don’t care to spend the extra few dollars for these options, so we will add them ourselves….
Pull-out Freezer Drawer – The 7300 used in the newer 24FL and 24A Gallerias has a pull-out freezer drawer, while the older models have a side-hinged freezer door.
TIP#179: Removing the Freezer Drawer – To remove the freezer drawer, extend the drawer out all the way and hold the plastic latches in the rails. One lever goes up, the other down, and you can pull the drawer straight out of the rails.
To re-insert the freezer drawer, push the slides in and align the drawer’s slides with the cabinet slides. Push the drawer in all the way, and they should latch.
TIP#178: Adding Pull-out Drawer – If you have an older model 7300 refrigerator and would like to have the pull-out freezer drawer, Nova Cool sells a kit that will allow you to upgrade to the pull-out drawer. We are on the fence about the usefulness of the drawer. You lose a small amount of storage space.
TIP#184: Ice in the Rails – There have been times when the freezer drawer has not opened due to ice building up in the drawer rails. Whether an ice-preventative spray is helpful is unknown.
TIP#026: Increase Refrigerator Cooling – Remove the drip tray. For best cooling efficiency, clean the coils under the refrigerator at the beginning of each camping season.
TIP#185: Freezer Latch – When we picked up our van, the latch on the freezer drawer would go up and over the catch bracket on the refrigerator cabinet instead of latching under it. We replaced the latch with a new one from Amazon and moved the cabinet bracket a little higher. We also filed an angle on the leading edge of the bracket to force the latch to go under it better. When closing, lifting the latch can ensure it engages under the catch.
TIP#183: Door Swing – The door hinge can be changed from the right side to the left by removing the hinge pins and latches and installing them on the opposite side.
TIP: To chart temperatures and humidity, we suggest using SensorPush Bluetooth thermometers in the refrigerator and freezer.
TIP#127: Decorative door panels can easily be changed to match your interior by removing the upper hinge pin, then pulling the door up and out from the lower hinge pin. Turn the door upside down, and remove the two Phillips-head screws, and roll the bottom extrusion towards the door gasket, being careful not to dislodge the door gasket. You will see a 1/4-inch channel where you can slide in your new panel material.
Fuse – The 12 volt DC fuse panel has a 15 AMP blade fuse for the refrigerator/freezer.
TIP#071: Magnetic Light Switch Bracket– One way to turn the light off when storing the refrigerator with the doors open is to use a rectangular magnet and a flat strip of thin, flat steel metal bent to hold the switch in the off position. The magnet was purchased at Harbor Freight.
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TIP#089: 11/20/2021 – Update – If you are a little more adventurous, instead of the magnet bracket, this next modification adds a small slide switch to turn off the light when the door is open for storage. The switch is wired in series with the light to allow the light to be turned off when the door is open in storage.
A contact switch is located in the front of the wiring cover. When the door is closed, it pushes on the contact switch and turns off the light. A thin plastic cover is screwed to the side of the refrigerator that contains the door switch, wiring, thermostat, and light.
This light control solution is to add a small slide switch in series with the door switch.
The plastic wiring cover is very thin, and creating a cutout for mounting the switch is easy with a small drill and a sharp X-Acto knife. The slide switch is then wired in series with the door switch.
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Circulation Fan – RV refrigerators have a reputation for not cooling very well.
TIP#060: Refrigerator Fan Mod – One solution is to add a small battery-powered fan to circulate the cold air inside the refrigerator. We can take this one step further by adding a centrifugal blower fan powered by the 12-volt wiring under the plastic cover that contains the thermostat and light. A pulse width modulated (PWM) speed controller allows turning the fan on and off as well as varying the speed of the fan. A 12-volt connector permits the fan to be easily disconnected and replaced if needed.
A Pulse Width Modulator (PWM) is used to turn the fan on and off and to vary the speed of the blower fan.
Inside the wiring cover are the door contact switch, the thermostat, and the wiring for the LED light.
The PWM controller board fits easily behind the thermostat, and the control shaft sticks out the side. A 12 volt power connector is mounted facing out the bottom of the cover so the fan can be disconnected if it ever needs to be replaced.
Final assembly with the knob installed on the PWM, the fan mounted on the adapter, and the 12 volt connector out the bottom.
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The compressors, coils, and cooling fans are mounted under the bottom of the refrigerator and exhaust out the front of the cabinet. Unfortunately, our build doesn’t appear to have proper air flow to the rear of the coils; instead, it draws air in through the electrical cabinet up above the refrigerator. It really needs better airflow, and this could be part of the problem people are having getting better cooling. Pulling air in the top cabinet, and down along the hot wall of the van, and out the bottom doesn’t sound very efficient.
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TIP#032: Defrost – When defrosting the refrigerator, create a tape “spout” to redirect the water to a bowl instead of running down the front of the refrigerator and onto the floor.
To turn the refrigerator and freezer off, turn each thermostat until they click.
Leave the doors open after defrosting or while the unit is in storage to allow the refrigerator and freezer to dry out. Leaving the doors closed could cause rusting or mold growth to build up inside the unit.
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TIP#269: Refrigerator Connector Problems – There have been multiple reports of issues with the 12 volt power for the refrigerator, which have been linked to improperly crimped connectors or blade connectors that aren’t correctly mated with the female socket connector. The power blade connectors contain an outer plastic insulator, and instead of inserting into the female connector, the blade connector is inserted between the plastic insulator and the metal female connector. One of Coachmen’s apparent weaknesses is wiring. Some of our large power cables on Gal_2.0 need to be replaced or properly crimped. It’s critical to get your electricity problems fixed if you’re having any. An electrical fire totaled our first Galleria, Gal_1.0.
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18 – Cooking
19 – Refrigerator
20 – Electronics