Questions for Members with Residential Refrigerators

[Craig P.]

Residential refrigerator conversions have become a hot topic, in light of the massive safety recalls on RV absorption refrigerators.

I have a question for those of you that have an RV with a residential style refrigerator (converted or factory installed). How well does your fridge work in CG’s with poor power?

I ask this, because we are Thousand Trails members, and a lot of TT parks only offer 30amp service, and it is usually poor at that. I always run a line meter inside the coach and have often had to switch the fridge over to LP when the in-coming power gets too low. My AutoFormer helps, but sometimes the power is exceptionally bad, especially on a crowded summer weekend.

My Intellitec EMS works very well, and I almost never experience a tripped breaker at the power pedestal. The problem is, the EMS will shed power in this order:
1. Water Heater
2. Refrigerator
3. Rear A/C
4. Front A/C

The factory installed water heater and fridge can both run on LP, so it makes sense to shed them first. The potential problem with a residential fridge conversion would be when the compressor first starts up (it uses a considerable amount of power). With the EMS wired the way it is, I could see the system shutting down power to the fridge when running both A/C’s on 30amp, and possibly never restoring it because of the high demand for power when that compressor wants to fire up. A fix of course would be to re-wire the EMS to shed power to the fridge last, but I’m not sure this can be done.

Comments?

Craig

[Brigadoon]

Craig,

I recently installed a 23 cu ft side by side residentail refer in our mh. Prior to the installation, I had the new refer sitting in my house and running for 3 days. During that time period I had the refer hooked up thru a Kill A Watt meter. I was able to monitor power usage when running and on compressor startup.

The refrigerator that I purchased is one of those energy star units that is supposed to be energy efficient. The compressor is one of those slow/soft start up types. The most amps that I observed on compressor startup was 3.98 amps. When running after startup it would use from .89 to about 1.5 amps. Of course there maybe some variations that I did not see since I did not have my eye glued to the meter, however, I did check it a good 40 times over 3 days. One time I unplugged the refer for a couple of hours then power it up and watched the meter for 5 minutes. It did not break 4 amps.

Eventually I'm going to run the refer off an inverter but for now it is just plugged into the original socket for power.

[JMonroe]

We have a residential fridge, but our rig was designed and set up for it. It is happy to run off one of the inverters if there is no shore power (we have two, each with its own set of 4 AGM batteries). Assuming your EMS will 'shed' power to the fridge only for the short period of time the extra demand exists, you should be OK. It would take hours for the fridge (which cools down much faster than the RV type) to "loose its cool". Also, I think you can program the EMS, in terms of what to shed in what order?

[Craig P.]

Quote:

Originally Posted by Brigadoon I recently installed a 23 cu ft side by side residentail refer in our mh.

Hi Terry,
Thanks for the reply. Your new refer is definitely energy efficient!

I don’t have a Kill-A-Watt, but the EMS panel in my coach shows current amperage draw. When my Norcold is switched to electric, it draws 4 amps, which is just a hair over what your residential draws on start-up, but much more than your’s does after start up.

Do you plan to boost your inverter and/or battery bank when you wire the refer to an outlet powered by the inverter?

May I ask what the make & model of your residential refer is?

Thanks!

Craig

[Craig P.]

Quote:

Originally Posted by JMonroe We have a residential fridge, but our rig was designed and set up for it. It is happy to run off one of the inverters if there is no shore power (we have two, each with its own set of 4 AGM batteries). Assuming your EMS will 'shed' power to the fridge only for the short period of time the extra demand exists, you should be OK. It would take hours for the fridge (which cools down much faster than the RV type) to "loose its cool". Also, I think you can program the EMS, in terms of what to shed in what order?

Thanks for the reply.

Have you ever experienced any issues when hooked up to 30amp service during a high demand for electricity, such as a hot summer afternoon?

I'm going to check with Intellitec on the possibility of re-programmiong the EMS.

Thanks.

Craig

[Brigadoon]

Craig,

One small correction to my above post. My wife, who was also watching the Kill-A-Watt meter, said she saw the meter indicating it was using power in the 1.9 to 2.3 amps range so it may use somewhat more power than I indicated above.

My current inverter is not very large. I may add a second inverter dedicated to the refrigerator. I'm not going to add batteries until I see how well my 4 house batteries handle the load. We do not dry camp and only drive 200 to 250 miles on moving day so we will not have long periods of not being hooked to shore power. Additionally, if it's hot outside we will be running the generator. Therefore, I will not be adding batteries until I see how the setup works.

I bought a Maytag side by side counter depth refrigerator model MCD2358WEB.

[JMonroe]

Quote:

Originally Posted by Craig P. Thanks for the reply. Have you ever experienced any issues when hooked up to 30amp service during a high demand for electricity, such as a hot summer afternoon? I'm going to check with Intellitec on the possibility of re-programmiong the EMS. Thanks. Craig

We've not yet experienced a 30 amp hook up with the new rig.

[jackrobinryan]

I installed building energy management systems WAY back. Haven't looked at my coaches but I would think changing what is shed and in what order should be simple. (assuming the items being swapped had the same control relay sizing...)

Rather than attempting to reprogram the EMS, why not just swap the control wires to the relays being used to shed the particular items? Then just swap or reprint the item labels on the EMS panel.

I'll be loking under the covers of my winnie system next time to the storage lot.

jack

[RV Wizard]

Quote:

Originally Posted by Brigadoon Craig, One small correction to my above post. My wife, who was also watching the Kill-A-Watt meter, said she saw the meter indicating it was using power in the 1.9 to 2.3 amps range so it may use somewhat more power than I indicated above. My current inverter is not very large. I may add a second inverter dedicated to the refrigerator. I'm not going to add batteries until I see how well my 4 house batteries handle the load. We do not dry camp and only drive 200 to 250 miles on moving day so we will not have long periods of not being hooked to shore power. Additionally, if it's hot outside we will be running the generator. Therefore, I will not be adding batteries until I see how the setup works. I bought a Maytag side by side counter depth refrigerator model MCD2358WEB.

The defrost heater(s) will likely pull more current than the compressor.

[Iron Man]

We have an all electric with a residental refrigerator. As with others the refer uses about 4 amps of power and our EMS system does not shed the refer circuit. We have camped with 30 amps seberal times with no issues.

[Brigadoon]

Quote:

The defrost heater(s) will likely pull more current than the compressor.

Yes, the operators manuel says that it can pull up to 7.2 amps, we have not had the
opportunity to observe that at this point.

[Gary RVRoamer]

Quote:

A fix of course would be to re-wire the EMS to shed power to the fridge last, but I’m not sure this can be done.

It is quite possible and the installation & service manual for the EMS (available on the Intellitec web site) shows how to do it. You don't actually rogram" anything, but you can configure the EMS for several different patterns, or in some cases simply swap a couple wires to change the order. Or simply remove the fridge circuit from the EMS, if you never want it shed. However, there may be times when you want the fridge to shift to its back-up (a separate inverter) if it is wired with that feature.

[jspande]

My Dometic New Dimensions refer gave up the ghost recently, and rather than replace the cooling unit, I spent a little more ($1450 plus shipping) to replace it with a Vitrofrigo DP2600 compressor refer. This is (almost) a drop-in replacement for 8+ cu.ft. double door RV refers, and runs on 115ac or 12vdc. It's the same width as the Dometic and about 6 inches shorter (requiring a little woodworking to fill the gap.

For those wanting to get rid of the fire threat but don't have space for a residential refer, this (or a NovaKool) is an attractive alternative. Mine uses just 40 watt-hr per hour (draws 4.5 amp at 12 volts when compressor runs), which is 5 times more efficient than the Dometic (actual measurements) and it cools better. I like everything about it better than my old Dometic.