oneway Report post Posted March 9, 2017 My wife has a hair dryer here. 1875 watts. If I understand you correctly then: 1875 W / 120 = 15.625 amps. so I can try to run that with the front A/C. Or is that too much amperage to add? 8 hours ago, kaypsmith said: One will need to know the amp draw of the device in order to know if that unit is compatible or not, that's why I recommend a heater. If your wife has a hair dryer, that can be set to high if it draws enough watts, some of them have the draw marked on them for each setting size. To calculate amperage at 120 volt, simply divide the number of watts by 120, the results is the amp draw. If in a campground, I would bet that a neighbor has one, ask if that person would plug it up for your test, it will not hurt their heater, it just will refuse to glow bright red when the generator starts to bog. Yes you can put several devices together to equal the top number of amps. I used to use 300 watt light bulbs to trouble shoot a circuit in a shorted device, plugged just ahead of the questionable device, it will glow bright, then removing one component of that device at a time until I found the faulty component, at which time the light will glow dim. To answer a question earlier about the tech checking resistance, if he used his test leads correctly on the compressor and found zero resistance, that would clearly indicate a shorted compressor, which means that it would do nothing but trip any breaker or start a fire if not checked by some type short circuit device, which in the case of the air conditioner would be the PTR, or whatever the weakest link may. By the way, I admire your persistence to learn. Share this post Link to post Share on other sites
manholt Report post Posted March 9, 2017 Is it only one setting or 2? Most HD I've had was 2 speed, high and low. If only one? Give it a try, not going to hurt. Carl Share this post Link to post Share on other sites
kaypsmith Report post Posted March 9, 2017 Will be perfect, actually a little better. Just turn on the front AC and turn on the hair dryer, start with a lower setting then move up through the settings starting with the lowest, let the generator continue to run for the test a couple of minutes, move to the next highest setting for a another couple, and so on, until you reach the highest. Each move up it is not uncommon to hear the generator sound as though it is reving up, it is, that's because it is keeping up with the load. You will trying to find the spot where the generator starts to bog down and start cutting out. If you reach high and no bogging and continues to run fine, the generator should be fine with an AC replacement. One thing that I did not mention, let the AC begin to cool and make sure that the compressor is working before turning on the hair dryer, at this point, you will be depending on the intellitec to do it's job also, after all it is part of the equation as well. Hope this works out well for you. Share this post Link to post Share on other sites
ziggyh Report post Posted March 9, 2017 oneway, did the last tech install a new start capacitor with a new PTCR and try to see if the compressor starts. If you only replace the start capacitor with out changing the PTC it will damage the new start capacitor. Before I would be looking at the price of a new AC unit I replace the start capacitor and PTCR and the run capacitor just in case it has failed as well. Also checking the resistance of the compressor coil may not be the best diagnostic step, If a coil is open, the resistance test will find it, If a coil is shorting the resistance test may not find it because the accuracy of the Ohm meter is not capable of reading very low Ohms accurately. Coils can also measure good with an Ohm meter but when power is applied to them the wires contract which over time causes shorting of the coils causing high amp draws. The compressor can also seize up and a resistance test will not pinpoint that. If you do want to check resistances of the compressor coils, you have a second working unit to compare to. I have replace many start and run capacitors on residential and RV a/c units and motors when people were told they need a new unit and the capacitors have always fixed it issue. Share this post Link to post Share on other sites
bm02tj Report post Posted March 9, 2017 In the last few years I have replace a lot of capacitors on HVAC equipment. They are cheap so that is the first step. Share this post Link to post Share on other sites
jrock Report post Posted March 9, 2017 If you can, get a megga it will test the winding insulation and show if it's breaking down. You might be able to take the rig to a motor shop and have them check it out. Share this post Link to post Share on other sites
manholt Report post Posted March 10, 2017 Wonder what happened to my response an hour ago? Share this post Link to post Share on other sites
wolfe10 Report post Posted March 10, 2017 1 hour ago, manholt said: Wonder what happened to my response an hour ago? No idea-- Have been doing seminars all day. Logged in just now. Probably got swallowed up by the dust cloud here before it got to the cell tower. Share this post Link to post Share on other sites
kaypsmith Report post Posted March 10, 2017 Quote To answer a question earlier about the tech checking resistance, if he used his test leads correctly on the compressor and found zero resistance, that would clearly indicate a shorted compressor, which means that it would do nothing but trip any breaker or start a fire if not checked by some type short circuit device, which in the case of the air conditioner would be the PTR, or whatever the weakest link may. I am terribly sorry that I missed something in my post. OP stated in an earlier thread that he had replaced the capacitor assembly with the complete kit provided to him. The original PTC was fried, therefore it had to be replaced. He installed the new assembly and it fried also. When he called a tech in to replace the replacement, the tech was obviously bright enough to check the resistance of the compressor before proceeding to install a third cap and components. I don't know what his reading was, but I doubt that his VOM was so cheap that it would not read 0 ohms (DEAD SHORT). Share this post Link to post Share on other sites
manholt Report post Posted March 10, 2017 Brett. That explains, why I have gritty teeth....truck sprayed water on six South today, then left and never came back. No dust on Linda and all the Prevost's, but I sure got it on 5th! Share this post Link to post Share on other sites
oneway Report post Posted March 10, 2017 I'm going to do the hair dryer test today before going any further. And I'll show a few capacitor pictures here as well. maybe someone can tell me if I was given the correct capacitor from the RV shop. just got a call late yesterday as well from Tech #3. A new A/C is $708 and about $200 to install. (Coleman Mach III). Share this post Link to post Share on other sites
oneway Report post Posted March 10, 2017 When I went to replace the capacitor here is what I did: I took the original capacitor in to the RV supply place and they matched up the numbers. They gave me a new capacitor that looks like the top picture with the (resistor?? I guess) between the terminals you see there. The guy thought maybe it was an updated version. That one I installed and it blew. Now....I went back and the second time they gave me a capacitor that looks like the bottom one. Is that the PTR/PTC there on the top? The red wire attaches to it, then it connects to a terminal on the capacitor. After looking at the initial blown capacitors pieces it is clear to me now that the bottom one would have been what i had originally. i have that hard start kit ready to install. But again, I don't want to just smoke test a part. The tech said the compressor did not have a dead short. He said something about the resistance was supposed to double between 2 wires that he tested and it wasn't double. I don't have a clue what that means. anyway....any input on the difference between the capacitors? Share this post Link to post Share on other sites
manholt Report post Posted March 10, 2017 Yesterday a Tech, we are at FMCA rally in Chandler, came out to look at Linda's front Colman AC with heat strip that has not worked in 10 days. He replaced 2 caps and the AC has been running fine now on both AC/heat...hers is a 2005 DP by Tiffin and sold as a 2006 ! Total bill $257. Carl Share this post Link to post Share on other sites
oneway Report post Posted March 10, 2017 "If the compressor isn't running there should be 3 leads common, run and start coming directly from the compressor. Check between the leads for continuity. Common to run, run to start, and start to common. If the resistance of 2 equals the total of the highest ohm reading between the leads the compressor is good and the problem is something other than the compressor such as low freon overheating it. If you get continuity or 0 ohm across any of the lead sets than the compressors internal windings are bad and can only bring fixed by a compressor replacement." I found the above quote on the web while searching for how to test A/C compressor resistance. This sounds like what the tech was saying when he said the resistance should "double". I've got a cheap VM. (Radio shack). I can test continuity and it gives me a tone. Still waiting to see if anyone can explain the difference between those 2 capacitors. Share this post Link to post Share on other sites
oneway Report post Posted March 10, 2017 And now to the Hair Dryer Test results: I put the coach on generator power and let it stabilize. A few minutes later the front A/C was put online and was stabilized for about 5 minutes. I added the hair dryer on low setting. Next hair dryer on high setting. Then I added in the electric water heater. Each time a load was added there was a slightly (if at all) perceptible sound difference in the genset. It ran everything without bogging down at all. I guess all roads lead to the rear A/C again? With all loads online the line voltage monitor shows wavering and even dipped slightly below the green arc momentarily.(top picture) With only the front A/C on the line voltage monitor shows a slight wavering and remained within the green arc.(bottom picture). now...... input? Share this post Link to post Share on other sites
jleamont Report post Posted March 10, 2017 WOW , that's great news!! If it were me I would be A/C unit shopping, sounds like the generator was not the problem. Several "RV TECHS" and a compressor were however the beginning of ones sanity loss . By chance were any of the techs named Rodger? Inside joke.... a few on here now are smiling now...YEA I went there! The quote you had of $200.00 for installation seemed OK. The cost of the unit was a bit high. The hardest part of replacing the unit is getting the new on onto the roof. Two ladders and a helper would be ideal, not very heavy, just clumsy and large. Getting the old one down....well I did a shot-put maneuver and watched it bounce off of the lawn several feet away. Share this post Link to post Share on other sites
kaypsmith Report post Posted March 10, 2017 That is great news about the generator. The cap in top photo appears to be a hard start cap without PTC, the bottom with PTC. I am guessing, but the tech probably saw that the two was not equal to the highest total ohms read, indicating an open, or break in the winding rather than a short. A short would definately create an arc situation blowing the cap, a no start and repetitive tries to start would probably cause the PTC to burn up eventually. Read as "1= Common to run, 2 = run to start, 3 = start to common. If the resistance of 2 equals the total of the highest ohm reading between the leads the compressor is good", common or neutral should, but not always, be white. And it would double if 1 and three read the same resistance. Share this post Link to post Share on other sites
oneway Report post Posted March 10, 2017 1 hour ago, kaypsmith said: That is great news about the generator. The cap in top photo appears to be a hard start cap without PTC, the bottom with PTC. I am guessing, but the tech probably saw that the two was not equal to the highest total ohms read, indicating an open, or break in the winding rather than a short. A short would definately create an arc situation blowing the cap, a no start and repetitive tries to start would probably cause the PTC to burn up eventually. Read as "1= Common to run, 2 = run to start, 3 = start to common. If the resistance of 2 equals the total of the highest ohm reading between the leads the compressor is good", common or neutral should, but not always, be white. And it would double if 1 and three read the same resistance. Ok. So the compressor has 3 wires: red, black, white. I understand white is supposed to be common. so so do I just test: red-black, black-white, white-red....and I'm done? And I'm not looking for continuity (the tone)? But measuring resistance and looking for 2 numbers to add up to the 3rd? I might as well try this part out and see what I get. I've lost all faith in the techs here. I'm close to putting that 2ndstart cap on with the PTC and just trying it. It would be a $37 experiment. No big deal at this point. Share this post Link to post Share on other sites
kaypsmith Report post Posted March 10, 2017 OK, assuming that white is common, white to black, white to red, if ok black to red should be equal to the sum of the first two. Or think in these terms, if white to black = 42, then white to red = 42, then if black to red = 84, then the compressor is probable ok. This is assuming that white is common, and as stated it usually is, but also, remember sometimes manufacturers are strange animals, they may have used black as common. You will need to set your VOM (volt ohm meter) to read ohms (resistance), most meters have several settings, (0-999,1k-2k) and so on, start with the lowest setting, if no reading, move switch to the next highest, until a reading is obtained. Remember the numbers that I used is just an example, if I had schematics/maintenance manual for your unit, those numbers would appear there, but I don't have them at my disposal. And yes, all you have to lose by replacing the cap with the new one, (the one with the black PTC) on it, is the part if it blows again. If it works, will be wonderful. If you do replace it, don't put any part of your body close and have someone else "TRY IT", for safety sake. Share this post Link to post Share on other sites
oneway Report post Posted March 10, 2017 Thanks for all the insight! there is a schematic inside the door that houses the capicitors. I will do a test and see what I find. May not be until Sunday. Tomorrrow I'm going to watch the Blue Angels fly in El Centro! I'll post my findings here as well so that others can learn from my experience. I'm learning as I go. Never done this before. My MANY THANKS to everyone who has helped me this far. Share this post Link to post Share on other sites
kaypsmith Report post Posted March 11, 2017 Wish I could be there tomorrow, I love to watch the Blue Angels, have already their show in Pensacola Florida this year. Share this post Link to post Share on other sites
wildebill308 Report post Posted March 11, 2017 Lots of great advice. Here is a suggestion on geting the new one on the roof. I put the new one in the back of my pickup and backed up to the side of the coach. I used a part of an extension ladder as a ramp and just slid the new AC up the ladder to the top of the roof. The new one wasn't that heavy. PLEASE watch out for sharp edges to any metal on the AC they are stamped parts and tend to have supper sharp edges. Bill Share this post Link to post Share on other sites
manholt Report post Posted March 11, 2017 If you use Bill's advise. which I have done, I got a mountain bike inertube (old one) and cut a 12" section out, cut it in half length wise and wrapped each leg where it touched the roof. Protects the roof and gives the ladder more stability! Share this post Link to post Share on other sites
wildebill308 Report post Posted March 13, 2017 One other thing use some wooden blocks on the roof so you can set the new AC down with out damaging the roof or the new AC. Carl is right it is good to pad the ladder to protect the edge of the roof. Bill Share this post Link to post Share on other sites
oneway Report post Posted March 13, 2017 OK. this is just a thankyou picture for all the help. The story continues next.... Share this post Link to post Share on other sites
