Replacing A Norcold Refrigerator

[desertdeals69]

The rating of an alternator is at the max output and not continuous output which is roughly one half the max rating. When I installed my ISB Cummins into my coach the stock alt was a Delco about the size of an automotive one. It was 160 amp rated which was the highest for that frame size. I had 6 6 volt and 2 group 31 12 volt batteries and I burned up 2 alternators. I went to the next larger frame size Delco and had it built to 245 amps and it has been charging as it should for 13 years and over 100k miles. We use the microwave on the inverter while going down the road without any problems.

[huffypuff]

This is DC to AC amperage conversion run through an Inverter: 120 volts AC @ 5 Amps = 600 Watts. Convert that to 12 volts DC = 55.2 Amps DC.

Microwave oven 120 volts @ 7.1 Amps = 850 Watts. Convert that to 12 volt AC = 78.38 Amps DC.

This does not include if the refrigerator goes into defrost cycle or icemaker heater kicks in to expel ice from the mold. With that in mind the amperage of a refrigerator could go over that of a microwave.

There is an easy calculator at link below

http://www.batterystuff.com/kb/tools/ac-to-dc-amperage-conversion-run-through-an-inverter.html

[tbutler]

Just catching up here. We've run the refrigerator on full time when traveling. The alternator is the original, (Leece-Neville, 160 Amp standard) now twelve years in service and five years traveling with the residential refrigerator. We only run the generator when driving while we are using the roof air conditioners. We do keep the generator on the auto-start setting normally so if our house battery charge level drops the generator would kick in. We've never had the generator auto-start while driving. It will auto start during the night if the furnace is running quite a bit, even before we had the residential refrigerator.

So I went to our users manual to review the information and make certain my information is correctly stated.

"The alternator also maintains a charge to the house batteries. The function of the alternator is an electrical system voltage maintainer, not a battery charger. When traveling the alternator maintains electrical system voltage relative to any loads, such as headlights,and windshield wipers. When a heavy load is placed on the alternator, such as trying to charge dead batteries, the operating temperature of the alternator for extended periods of operation can lead to premature failure of the alternator. If the house batteries are in a low state of charge, or dead, before traveling it is recommended to charge the house batteries with the inverter/charger or an auxiliary battery charger."

There is a note: "Excessive loads applied to the inverter can actually drain both the chassis and house batteries during operation."

The only cautions are about charging batteries while driving. Charging batteries is a long term continuous load which can overheat the alternator when added to its normal functions operating the engine and chassis accessories. As a battery maintainer the alternator is sensing the voltage of the house batteries and adding charge as needed to maintain their voltage. The refrigerator is operating intermittently, the compressor runs for a few minutes and then is off. House battery voltage may drop slightly during this operation and the alternator may briefly add a charge to offset this voltage drop but it also is intermittent. This should not cause overheating as it is not a continuous large load. We run with our inverter on 24/7 when we are traveling. I can't imagine that the ordinary loads of charging phones would be a problem. My iPhone charger indicates .5 amps, the iPad charger draws 2.1 amps. The cautions about charging batteries is directed at the house and starting batteries. The information on our battery maintainer states that it provides up to 15 amp charge to the chassis batteries. A continuous 15 amp load is way different than a phone charger, even three iPads would be just over 1/3 of 15 amps.

I'll sometimes have my laptop plugged in and charging when we travel, we have a GPS plugged in to the 12V outlet. We have two clock radios, sometimes the furnace, water pump, etc. I've never seen a problem. We can't operate the microwave without the battery voltage dropping and then the generator kicks in to provide power for the microwave. One final aha! that may be a difference. Our coach came with a single solar panel which is capable of delivering up to 5A charge per hour during the mid-day hours (5 hours centered on noon solar time) and lesser amounts the rest of the day. These are our usual driving hours so this added help is assisting the alternator input to charge the batteries. This could be enough to make a significant difference.

There are no doubt different electrical system operating processes on different coaches. The above is what is specified for our coach.

[huffypuff]

Puff, I cannot speak to the model alternator that is in our coaches as far as reliability goes in the RV industry. My experience with Leece Neville in the trucking industry and emergency vehicles has not been good, they were always prone to premature failures. After saying that it is on my list to upgrade to a Brushless 170 or 240 Amp Delco (36SI or 40SI model) before it dies and leaves me stuck.

When I was working fleet with emergency vehicles we had a outfit claim that Leece Neville is bad and converted them to Delco. In fact a pair of them. Because of overheating the rectifier bridges were removed from the housing to the grill. Still have problem with heat with either the rectifier or winding burning up. First the company came to educate the mechanics. Then they came to educate the drivers. Fast idle solenoids were installed and resulted in mostly Ford vehicles overheating the exhaust to a point that the inside carpet would smoke. We didn't have any more problems with Leece Neville over Delco on the dump trucks or tractors.

I'm not going to say I'm an expert in alternators but Leece Neville being unreliable has not been proven to me. They will all fail if overheated for a period of time.

[desertdeals69]

This is DC to AC amperage conversion run through an Inverter: 120 volts AC @ 5 Amps = 600 Watts. Convert that to 12 volts DC = 55.2 Amps DC.

Microwave oven 120 volts @ 7.1 Amps = 850 Watts. Convert that to 12 volt AC = 78.38 Amps DC.

This does not include if the refrigerator goes into defrost cycle or icemaker heater kicks in to expel ice from the mold. With that in mind the amperage of a refrigerator could go over that of a microwave.

There is an easy calculator at link below

http://www.batterystuff.com/kb/tools/ac-to-dc-amperage-conversion-run-through-an-inverter.html

The one thing I noticed when traveling on flat level road with no wind, when the microwave is turned on the mpg drops 1/4 mpg. Usually the microwave is only on for a minute or two. We have used the crock pot for several hours without problem. I think the key is to have a large enough alternator. We have a 10 cu ft residential fridge. Once I had a problem with the dash heat and used a 1500 watt electric quartz heater running off the inverter for 1400 miles in the middle of winter.

[huffypuff]

The rating of an alternator is at the max output and not continuous output which is roughly one half the max rating. When I installed my ISB Cummins into my coach the stock alt was a Delco about the size of an automotive one. It was 160 amp rated which was the highest for that frame size. I had 6 6 volt and 2 group 31 12 volt batteries and I burned up 2 alternators. I went to the next larger frame size Delco and had it built to 245 amps and it has been charging as it should for 13 years and over 100k miles. We use the microwave on the inverter while going down the road without any problems.

You just proved what I was talking about all along as Delco at same amp rating is no better than Leece Neville. Having a larger frame with internal fans and more amp rating helps. Maybe this should be part of the project when changing to a residential refrigerator. The point made is if you are running it at or near max rating it will overheat the alternator. I can change my alternator to a 200 amps Delco but have to be very careful when to put the voltage sense wiring. I was dealing with ExtraRide insurance so not able to do that. The replacement is supposed to be improved but I guess we heard that before. Supposedly a shop converted one member on here to Delco and did the voltage sense wire wrong and had many problems. He went through three replacements before he found the problem. I can't seem to find the post.

Found similar post at this link:

http://news.prestolite.com/node/4840

[jleamont]

^{Puff, good info, I am at 132.48 Amps DC worse case scenario while in defrost.}

[CAPKELLY]

I would like to replace my Norcold side by side 12 cubic ft. It is the Norcold 1210 imss. I have a 2007 40' Monaco Knight. My concern is how they would remove the Norcold and get the residential refrigerator into my coach. I would have a service center do the work But one center said they might need to remove windshield to do this. I really do not want to have the windshield removed. I have had windshield replaced 4 times for cracked windshield in past. None in 4 years! THANKS.

[jleamont]

Capkelly, I removed one of the side windows. Look up your refrigerator specs on the web and start measuring the windows on the side and the entry door. Some have carried them out the door. I wasn't that lucky, ours came out the side window behind the passenger seat. It would have fit out every window in our coach except the one in the restroom and in the galley. I would not remove the windshield for this.

[lmsooter]

I would like to replace my Norcold side by side 12 cubic ft. It is the Norcold 1210 imss. I have a 2007 40' Monaco Knight. My concern is how they would remove the Norcold and get the residential refrigerator into my coach. I would have a service center do the work But one center said they might need to remove windshield to do this. I really do not want to have the windshield removed. I have had windshield replaced 4 times for cracked windshield in past. None in 4 years! THANKS.

I don't know what floor plan you have, but looking at the Monaco brochure, it appears that you probably have a large sliding window over either a dinette or sofa. We have large sliding windows at the dining table and sofa in the driver side slide in our Alfa. Our installer removed the window at the dining table because it was closer to the refrigerator. They took the Norcold out through the window with a forklift and brought the new refrigerator in through the window with the forklift. I would not remove the windshield. The guy that did our install has done over 100 installs - they work on other coaches but specialize in Alfa.

[jleamont]

Capkelly, that is the same model we removed.

[manholt]

Joe. Did you totally dismantle as much as possible on your Nocold before taking it out the window?

It is now 4:05pm at Perry, time for wine, cheese and crackers! Also cold...for us Southern folks! 63 with a WNW 23 mph wind. It's been in the 80's all week...

Carl

[jleamont]

Carl, I removed the fans on the back and the doors, I didn't remove the cooling unit.

Enjoy your wine and cheese!

[CAPKELLY]

Thanks to all for you posts and help. Kevin

[SherryCasteen]

Lol!, you are funny Herman! Thanks for all the information on the RR. I believe we will do that also. Our Norcold 1200 just quit cooling in the refrigerator part but the freezer works great!, EVEN KEEPS ICE CREAM FROZEN! Any other suggestions?

Sherry

[abyrd]

I'm in the same boat, I have the doors off the Norcold and have a Samsung 17.5 cu ft French door model on order.  It look like there is going to be no problem getting either units thru the doornonce I remove the passenger chair.

 

Jim

[SherryCasteen]

Thanks for the information Jim.

Sherry

[jleamont]

Sherry, ours started to fail the same way, freezer seemed to be fine the refrigerator was holding a whopping 56 degrees.