RVP MACH 8 A/C Two Blade Fan!

[voltdoc]

Originally Posted by Ultratravler

Rob, Thank you very much. I wonder, if or when they find a fix for this problem, do we need to contact them to get on a list to receive the new up dated fans. Thank goodness its winter, hopefully they will find a fix for this problem by spring.

Dave

Dave , RVP is saying about a month for availability of the new design. I don't know if they will proactively notify owners, but I will certainly post here when I hear anything. BTW have you looked at your blades, and do they show the cracks?

[voltdoc]

Most Entegra owners probably received fan part# 1472B504 in their 3 blade "quiet" fan kit.

The original version was presumably an "A" part and according to RVP the "B" fans are made of a stronger material. Unfortunately though, still not strong enough.

The "C" version of the fan is made of the same material as the "B" version, but has slightly thicker hub material where the fan mounts on the motor shaft - this eliminates the need for a second washer under the fan hub that most of us had to add with the "B" version of the fans. The extra washer was needed to ensure the motor shaft was slightly recessed below the top of the fan hub - if not used, the fan could be slightly loose on the motor shaft.

The improved fan design (available in 1-2 months) will probably be the "D" version and will hopefully put the stress cracking issue to bed.

[CA_Tallguy]

Count me among those having the crack issue. Indeed, I am also a full-timer and used the AC extensively over the summer (in Texas). Mine failed after only 3 or 4 months!

[voltdoc]

Hi all, I set up a separate thread for reporting any RVP MACH 8 3-blade fan failures or cracks in the blades:

http://www.irv2.com/forums/f278/plea...re-228386.html

If you had a failure or inspected your fan and found cracks, please report it at the link above. I have sent that link to Engineering at RVP and also to Entegra so this will give RVP/Entegra a single point to gather how many of us of seen the problem without wading thru all the other posts on this and other threads.

The thread above also has links to photos of where to look for the cracks and who to contact at RVP if you also want to report the failure directly.

So far I count four of us that have reported a catastrophic fan failure, but there are likely going to be more.

[kzember]

Four days ago I installed the new "C" fan version supplied by RVP at no cost. Thank you RVP.

I have also upgraded the fan motor mounting nuts to stainless steel 10-24 nylon-lock nuts (4 for less than 2$ at local Home Depot). Fortunately, none of my motor-mount studs seem to be damaged!

The unit is running well. As there have been reports of similar fan failures with the "C" model, I will be monitoring this fan for any development of cracks.

I can only hope that the news of a new "D" model fan will put this issue to rest.

[hogdriver]

I replaced my fans in about June this year. Is there a way to tell which version I have A-B-C-D so I can update the forum on cracks if it happens? Did the markings or part numbers change on the fan.

[voltdoc]

Originally Posted by hogdriver

I replaced my fans in about June this year. Is there a way to tell which version I have A-B-C-D so I can update the forum on cracks if it happens? Did the markings or part numbers change on the fan.

That's when we first replaced ours too so my guess is you have "B" fans but to tell just look at the top of the hub, the part number is embossed there and will be 1472B504. The B in the part number is the indicator.

With the "C" fans the embossed part number stays the same but there is a white sticker over it that says 1472C504. It is possible over time that the sticker could come off from getting wet etc. I used a silver ink sharpie pen to mark an additional C on the fan and also wrote the date I installed them.

The other clue will be the date code - to see that you will need to remove the fan and look inside the hub. Embossed into the plastic you will see four "dials" with an arrow pointing at a number. One dial is the year (13-18), one is the month (1-12) and the other two indicate the day.

Phil at Airxcel told me date codes around 2/14 were "B" pre-production models. Of the last three fans I received all were "C" fans with dates of 6/14.

NOTE: "C" fans have a thicker top section and should NOT require the second washer underneath the hub that many of us needed to add with the "B" fans to keep them tight on the motor shaft. If you have a "C" fan you still need one washer under the hub but not two.

BTW, the "A" fans were the original six blade models. Phil just mentioned to me that they have some of these back in stock if anyone wants to go back to them for the interim.

The new "D" fan protoypes will be at Airxel by around 12/20. Once they have passed muster, full production will begin in Jan and they should be ready for delivery around the beginning of Feb. The "D" fan will have a beefed up hub structure and be made of the same glass filled nylon as the previous blades.

Rob

[dusty56]

Voltdoc, I finally had a chance to get up on the roof to inspect the fan blade situation. All the blades look good. I was out west this summer and I used the AC the whole time.

When I installed the 3 blade fan I used a 1/8th inch large diameter nylon washer as a spacer. I also left the original washer on the unit. I wonder if the large washer helped keep the fans secure and steady. Just a thought.

I did notice on the midship Ac unit the mounting screw for the motor is attached but not to the cover as it should be. So the fan motor is moving around.

How big of a job is it to lift the ac unit so I can put a new nut and bolt? It really looks like it was never installed properly from the coleman factory.

[voltdoc]

Originally Posted by dusty56

Voltdoc, I finally had a chance to get up on the roof to inspect the fan blade situation. All the blades look good. I was out west this summer and I used the AC the whole time.

When I installed the 3 blade fan I used a 1/8th inch large diameter nylon washer as a spacer. I also left the original washer on the unit. I wonder if the large washer helped keep the fans secure and steady. Just a thought.

I did notice on the midship Ac unit the mounting screw for the motor is attached but not to the cover as it should be. So the fan motor is moving around.

How big of a job is it to lift the ac unit so I can put a new nut and bolt? It really looks like it was never installed properly from the coleman factory.

Hey Mike & Lisa! Hope all is well! Great that you are not seeing the blade cracks develop! I bet Phil Robinson at RVP/Airxcel would love to know what date code your fans have (see post below - it requires removing the fan). There was a theory at Airxcel that some of the fans were made of improperly processed material prior to 5/14 which might be the source of the cracking, but that is not currently the suspect according to Phil.

In regard to the second washer that many of us had to put under the hub, that is almost always needed with the "B" fans (see post below). If you have a "C" fan, which has a thicker hub, the second washer is usually not required. I had the extra washers on my B fans (no wobble or looseness) and they still cracked (date code 2/14).

Yes I think you are right that the loose fan motor mounts (Airxcel calls them "isolators") are a factory issue - in one of my conversations with Phil he mentioned that they made some revisions to the production line to reduce the incidents of the "isolators" not getting tightened properly.

If the screw coming up thru the bottom into the rubber isolator has not completely backed out of the AC unit housing, you can usually screw the isolator back onto it from the top without removing the AC unit.

If for some reason you do need to lift the AC to get the screws back in, it is about a 15 minute job. You remove the inner (gray) cover via the four exposed 3/8" nuts, then you will have access to 4 large bolts that hold the entire unit to the roof framing. You will also probably need to disconnect the condensate drain tubing so you have enough slack to lift up the unit enough to get your hand underneath to reinsert the screws. The unit is heavy so be ready with a box or something to prop it up while you work on it.

Hope this helps!

Robb & Linda

[dusty56]

Rob thanks for getting back to me. I trust all is well and Happy holidays to you and Linda.

Well I spent the afternoon on the roof. You were correct the fix for the motor isolators is straight forward. Just had to get a 10-24 bolt and lift the ac to re-install it.

After the fix I looked closer at the fan blades. They are not cracked but they are not round anymore. I also noticed on the front unit and mid ship unit they scuffed the metal electrical box. I looked at the situation even closer and determined that the rubber isolators are engineered to absorb movement or stress. I think the current combination of fan blade with the engineered isolators could be problematic. If they design the blades they should provide for additional clearance. JMO.

Anyway long story short, I went back to the originals. Mine would of failed eventually. I also believe the isolator on the mid ship AC was never installed correctly. No big deal problem solved.

Well I am noisy again! What a difference in outside noise level. Inside a little but not enough compared to outside. Well I will wait for the fix.

[C310]

Originally Posted by dusty56

Rob thanks for getting back to me. I trust all is well and Happy holidays to you and Linda.



Well I spent the afternoon on the roof. You were correct the fix for the motor isolators is straight forward. Just had to get a 10-24 bolt and lift the ac to re-install it.



After the fix I looked closer at the fan blades. They are not cracked but they are not round anymore. I also noticed on the front unit and mid ship unit they scuffed the metal electrical box. I looked at the situation even closer and determined that the rubber isolators are engineered to absorb movement or stress. I think the current combination of fan blade with the engineered isolators could be problematic. If they design the blades they should provide for additional clearance. JMO.



Anyway long story short, I went back to the originals. Mine would of failed eventually. I also believe the isolator on the mid ship AC was never installed correctly. No big deal problem solved.



Well I am noisy again! What a difference in outside noise level. Inside a little but not enough compared to outside. Well I will wait for the fix.

Dusty, I removed my 3 "B" fans and at first I thought they were ok after about 2 1/2 months of constant use. After looking at them again under a magnifying lens all 3 blades on all 3 fans had started to crack. If you can you might do the same with your blades. It might help others to detect early signs of failure. Thanks. Steve

[dusty56]

Thanks Good point I will let you know what I find.

[C310]

Thanks Dusty. Steve

[voltdoc]

Originally Posted by C310

Dusty, I removed my 3 "B" fans and at first I thought they were ok after about 2 1/2 months of constant use. After looking at them again under a magnifying lens all 3 blades on all 3 fans had started to crack. If you can you might do the same with your blades. It might help others to detect early signs of failure. Thanks. Steve

Hey Mike, agree with Steve, especially after I saw your photos - not 100% sure but I think I can see some early signs of separation. Try to run your fingernail around the hub edge (the 1/8" thick section that faces downward when the fan is installed), it should be smooth all the the way around, but when the cracks start you will feel a slight ridge right about where each blade meets the bottom of the hub.

Date codes looked to be 2/14, same as my three broken fans.

Phil at Airxcel just sent me 3 of the "D" fan prototypes to try out - guess I am now an official Airxcel field engineer (still waiting for my first paycheck though). Will install these later this week and report back on the design changes. The full production run "D" fans will probably be available around the end of Jan.

Merry Christmas!