Warm tomorrow and wanted to test the a/c - it's a Coleman Mini Mach, 7,200 BTU/20 amp. I've tested lights but nothing that draws more power than that. That went well - mostly LEDs, anyway. I have a fairly regular extension cord (nothing high gauge) running about 25 feet from a dedicated basement outlet and a converter that steps down the 30 amps. Regular house style fuse box in the camper - can I test the a/c for ten - fifteen minutes, to see if it blows cold, without creating a fire hazard or stressing the a/c? Thanks for any opinions!

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FYI - Lakota answered this in private message - said he thought to run for 5 minutes to just see if the compressor came on and it blew cold would be okay since it's only 7,100 (or 7,200) BTU.  I did not do it though as it meant serious un-tarping and we had high wind warning for this afternoon evening.  Next warm spell, though.

Good morning, Dawn Michelle; 

I need some more information:  What do you mean by "converted house current" and what is your "converter that steps down the 30 amps" that you mentioned?  

And I am surprised that your 7,200 Coleman Mini-Mach calls for "20 Amperes" of 120 VAC electrical power.  My Coleman Delta-TX air conditioners at 15,000 BTU  each draw only about 14 Amperes of 120 VAC shore power or generator power.  I would expect your smaller air conditioner to be in the 8 to 10 Ampere current draw range. 

Part of the problem is that the RV industry uses a lot of words that may have a special meaning in their context, such as "adapter" for changing from a three blade RV 30 Ampere 120 VAC electrical power socket to a regular three blade 15 Ampere household type 120 VAC socket for plugging in a regular electrical power extension cord.  Knowing what all the words mean to all of us would really help, especially when it comes to electrical power systems.  A "converter" is usually the electrical device that changes the 120 VAC shore power or generator power into 12 VDC for the batteries, lighting, fans, control boards, and other things in the RV.

And I have not been able to find any information on the Coleman Mini-Mach 3761 7,200 BTU air conditioner that tells me how much electrical power it requires. 

Enjoy;  Ralph, Latté Land, Washington 

Morning Ralph - 

You are correct, that's what I meant, when you say an "adapter" for changing from a three blade RV 30 Ampere 120 VAC electrical power socket to a regular three blade 15 Ampere household type 120 VAC socket for plugging in a regular electrical power extension cord."

The adapter is basic Camco converter.  Afraid I don't know the gauge of the extension cord, only that it's typical light duty, outdoor style.  I've plugged in and turned on the circuit breaker box in the RV but the only thing I've done is tested the lights at this point and toggled the water pump just to see if it came on (it did).

And a better thing to say is that it's on a 20 amp circuit breaker in the RV itself which is what is recommended in the owner's manual.  

According to the notes on the circuit breaker box - the other three fuses are 15 amp and the a/c is the only thing marked on the 20 amp.  Another 15 amp is dedicated to microwave (not a built in one so have to determine the outlet), another to GCFI outlet and lights and then a final goes to "misc".  The toggle for the whole box is a 30 amp.

Other than letting me know it's rated at 7,100 BTU, it says it "is a two speed air conditioner which operates from a 115 VAC, 60 Hz single phase power supply."  And that it requires min #12AWG for wire lengths up to 25 feet.

I don't have to test it right away - I can wait til I get to a park and plugin to 30 amps to test but it would be a nice timesaver.

I hope that clarifies the muddy water?

Wow.  That was fast.  Thank you for the very prompt response. 

OK.  If you look on the Coleman air conditioner, there will be a label on it where it will tell you what voltage it wants to be plugged into, and either how many Amperes of electrical current it will draw, or how many Watts of electrical power it will use.  Mine were visible when I used a screwdriver to take out the screws holding the plastic cover on the bottom of the air conditioner up on the ceiling inside the RV.  That also gave me the exact Coleman model designation for my Coleman Delta-TX air conditioners.  Those numbers or designations really come in handy when you are asking for parts or accessories for it.  It turns out that there were several versions of the Delta-TX.  It is nice for me to know which one I have.

And that is where I also saw how much electrical power it draws, which is 1,350 Watts, or 11.25 Amperes of 120 VAC current, but the compressor motor starting current may be higher for a short time.  There is a small printed tape label I put on the inside cover of the Delta-TX with this electrical information also (I just went out and looked at it), so I can know what I can have on at any one time in the motor home. 

Your microwave oven may have a dedicated 120 VAC electrical socket in the space behind where it is mounted.  Often they will do this also for the other appliances that use 120 VAC, such as the refrigerator. 

OK.  Now for your question:  With your 15 Ampere rated electrical extension cord (usually will be marked as being 14 AWG wire), you can plug in and try running your Coleman Mini-Mach air conditioner.  You can also use a "heavy duty" extension cord marked as being made with 12 AWG or even 10 AWG wire.  Running your air conditioner, your refrigerator, your furnace, and the other electrical appliances in your RV every month or so really is a good idea to keep them in operating condition during a storage period.  Your owner's manual for your 120 VAC generator may tell you to do this also.  Same kind of an idea for your other electrical appliances, including the air conditioner.   Often the generator owner's manual will suggest running the air conditioner while operating the generator during this exercise period as an electrical load on the generator.   

There sure are a lot of things in a motor home or RV for us to learn about.  When you are "getting away from it all" while taking "all the comforts of home" along with you, it does help to know how all of these systems work when you are out there, and now you are responsible for all of those things that back at home we just take for granted, because "they are always there." 

Enjoy;  Ralph, Latté Land, Washington 

Thanks Ralph, and great advice.  Appreciated!

I hadn't thought about testing everything regularly.  When we had an RV before (we full-timed for a couple of years ) we were really were clueless about (most of all) our electrical system. Had several issues and as I've mentioned here and there on this forum, in retrospect, we are really lucky we didn't burn ourselves down.  This time I'm approaching with more caution and respect.  Of course I now also have the leisure to do so.  I'm pretty excited about learning basic wiring concepts and soldering good connections.

I suspect a better extension cord is in my future if only for testing purposes.  Of course I do hope to get her out at least once a month, but rather not be fixing things on my free weekend :-)

I'll take a look and see if I can find a label - not one on the outside of the unit (interior) so it will have to wait for another weekend.

It's also good to note Dawn, that the shorter the length of shore cable the better.. drawing to much current can melt down one of those 50' 16-awg econo cords in a heart beat. 

Thumbs up!

And the longer the extension cord the more line loss, lower voltage, gets to the unit. That is real bad for air conditioner compressors. Put a volt meter in an outlet and monitor the voltage when you test your AC and if the voltage at the outlet drops below 105 volts shut off the air conditioner. The cord will not carry the load and you could damage the unit.

Thanks Rick - the extra info about what to watch on the plugin voltmeter will help as I have one of those. I finally ran down where someone had a coleman mini-mach and says it draws about 7-8 amps (now it may be more on startup). I've got to double check the length across the yard and make sure it'll make it with my plugin also pulled to full length, but should be able to get away with 25 foot cord and most likely 14 gauge? I read that house current was only wired on 14 gauge anyway so the breaker would trip if it stressed on that end. But since it's a 30 amp on the other end I didn't know how to protect my a/c - but it seems you've answered that question for me. I read that 14 gauge for that distance should be good (I am thinking it won't be going over a 15 amp pull - it's the only thing I'm going to test...)

You should be good to go. Start up current, often called in rush current can be several times the rated amps in some circumstances like: a big motor, stalled motor, or stuck compressor. If you throw the switch and it trips the breaker I would suggest unplugging it and have it checked out by an electrician.

Something to remember........ Electricity DOES NOT GO to an appliance,,,, the applaicance PULLS the current,,,, Electricity sits idle  till it can find a path to ground,, whether by a short or a completed circuit.




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