Foretravel Motorhome Forums => Foretravel Tech Talk => Topic started by: dixie flyer on June 10, 2016, 06:24:54 pm
Title: What's this? (blower found in bay)
Post by: dixie flyer on June 10, 2016, 06:24:54 pm
I have 2007 Nimbus 336 Foretravel. I heard something running and traced it to the compartment where the inverter is located along with the hydraulics. Here are pictures of a thermostat and a fan. What setting should the thermostat be set and what is the function of the fan?
(https://www.foreforums.com/imagecache.php?image=http%3A%2F%2Fi21.photobucket.com%2Falbums%2Fb251%2FDixieflyer2%2Fcoach%2520bay%2520and%2520kitchen%2520013_1.jpg&hash=8115e36e763f231221bf1d81a94ceb84" rel="cached" data-hash="8115e36e763f231221bf1d81a94ceb84" data-warn="External image, click here to view original" data-url="http://i21.photobucket.com/albums/b251/Dixieflyer2/coach%20bay%20and%20kitchen%20013_1.jpg)
(https://www.foreforums.com/imagecache.php?image=http%3A%2F%2Fi21.photobucket.com%2Falbums%2Fb251%2FDixieflyer2%2Fcoach%2520bay%2520and%2520kitchen%2520014_1.jpg&hash=a23fee3f9fdf54a54aa8e33ac60796d9" rel="cached" data-hash="a23fee3f9fdf54a54aa8e33ac60796d9" data-warn="External image, click here to view original" data-url="http://i21.photobucket.com/albums/b251/Dixieflyer2/coach%20bay%20and%20kitchen%20014_1.jpg)
[edited topic title to be more descriptive - Michelle]
Title: Re: What's this?
Post by: Roger & Susan in Home2 on June 10, 2016, 06:40:47 pm
It is a bay heater. Set the thermostat to 40° or so. Looks like it is at 80°.
Title: Re: What's this?
Post by: RvTrvlr on June 10, 2016, 06:54:54 pm
Roger may be correct, Ive only looked at a handful of older FTs, but Ive been RVing for a long time, Looks like just a ventilation fan, to remove heat, to me? could be a heater, but the fan is running into a plain hose.. I dont see any way for it to make heat. The thermostat doesnt even go low enough for your average freeze protection settings.
Also dont know why the hydraulic/electrical bay would need to be heated.. especially since the inverter generates a lot of heat.
Title: Re: What's this?
Post by: dixie flyer on June 10, 2016, 06:55:13 pm
If I set it on 40 it keeps running. If I set it on 85 it cuts off.....
Title: Re: What's this?
Post by: oldguy on June 10, 2016, 07:18:19 pm
I would leave on 80 as it looks like it's there to keep that area from getting to warm.
Title: Re: What's this?
Post by: rbark on June 10, 2016, 07:22:50 pm
The squirrel cage fan in to remove heat from the compartment. Gets quite warm in there with all the electronics. Looks like someone added the adjustable thermostat. The gray box attached to the fan housing has a preset thermostat in it. Possable the previous owner installed the other one
Title: Re: What's this? (blower found in bay)
Post by: Michelle on June 10, 2016, 07:41:30 pm
What Richard said. In that bay it's ventilation due to the inverter and other electronics being there. It is not a bay heater - that would be in the wet/plumbing/tank bays.
Now, the thermostat is not something I've seen before and operating the way it does, it definitely seems backwards. Perhaps a DIY attempt by a previous owner that wasn't done correctly?
Title: Re: What's this? (blower found in bay)
Post by: Tom Lang on June 10, 2016, 07:50:30 pm
Possibly an added thermostat hay wired by the P.O. That should be a preset temperature cooling fan that turncoat on above the preset. It appears to be turning off above 85 when the knob is set to 85. This is how a heater thermostat would work.
Can you feel the outlet hose? Does it get warm or stay cool? It doesn't look like a heater. And where does it lead? Is he taking waste heat to some other bay?
I can think of no reason to ever heat this compartment?
Title: Re: What's this? (blower found in bay)
Post by: Beerslayer_24 on June 10, 2016, 08:36:12 pm
There are two types of thermostats. One thermostat, switch, closes on temperature rise, this is a cooling thermostat. Another type of thermostat closes on temperature drop, this is a heating thermostat.
Title: Re: What's this? (blower found in bay)
Post by: Roger & Susan in Home2 on June 10, 2016, 08:37:22 pm
Second look ... I agree, most likely for exhausting heat from the bay. Interesting thermostat add-on.
Tom, in MN when it is -30° every bay needs heat.
Title: Re: What's this? (blower found in bay)
Post by: Tom Lang on June 10, 2016, 08:58:26 pm
There are two types of thermostats. One thermostat, switch, closes on temperature rise, this is a cooling thermostat. Another type of thermostat closes on temperature drop, this is a heating thermostat.
If I set it on 40 it keeps running. If I set it on 85 it cuts off.....
These thermostats are brain-teasers. To state Bob's explanation another way, when you turn "down" a cooling thermostat, it will turn on to attempt to reach the colder temperature requested. This is what Dixie Flyer said was happening. In summer temperatures the 40 degrees will never be reached without some type of additional cooling, so the fan would run continuously.
When you turn "up" a cooling thermostat, it will turn off when the temperature matches the ambient temperature (85 degrees in this case) - because cooling is no longer being requested. Again as Dixie Flyer stated was happening. When set at 85 degrees and fan off, if the temperature would rise above 85 degrees, the fan would turn on, as stated by Bob, to try to reduce the temperature back to 85 degrees, and then shut off again.
This is the way the kitchen Fantastic vent thermostat works, this is also a "cooling" thermostat.
Title: Re: What's this? (blower found in bay)
Post by: Beerslayer_24 on June 10, 2016, 09:24:25 pm
I agree with Tom, the blower is exhausting the hot air at the top of the electronics bay.
Not knowing what the ambient temperature is, a cooling thermostat will energize when the ambient temperature rises above the set point. It may seem counter-intuitive, but lowering the set point on a cooling thermostat once it is energized has no effect. One would have to raise the set point to above ambient to open the contacts, on a cooling thermostat.
Some thermostats include both functions, that is another discussion.
Bob
Ah, I see Peter has posted as well, thanks.
Title: Re: What's this? (blower found in bay)
Post by: bobnkathy on June 10, 2016, 10:01:30 pm
This is an exhaust fan. Leave it set for 80 degrees. Also, up high on the back wall where the transfer box is mounted, you will notice the wall has openings to the other side cabinet. Be sure these areas are not blocked with items from the other side. The exhaust fan will draw air in from those cabinets. The unit vents to the underside of the coach. There is a screen on the vent below to keep bugs and rodents out. I have found when in areas that the outside temp reaches near 100 degrees, to open the bay door an inch. I have made a tool to place in the opening to allow the door to remain open an inch. The inverter makes a lot of heat and it needs to be vented. Bob
Title: Re: What's this? (blower found in bay)
Post by: Michelle on June 10, 2016, 10:08:15 pm
This is an exhaust fan. Leave it set for 80 degrees.
The inverter makes a lot of heat and it needs to be vented. Bob
Bob,
Doesn't it seem to you that the installed thermostat is an incorrect one - as Peter and the other Bob (Beerslayer) have mentioned, if it's to exhaust heat as we all believe, the fan should run whenever the temperature is above the setpoint and shut off below it Richard (Dixie Flyer) is reporting it's shutting off when he raises the setpoint, which is not what a cooling fan's thermostat should do.
Title: Re: What's this? (blower found in bay)
Post by: prfleming on June 10, 2016, 10:31:08 pm
This is where it gets confusing...when you raise a cooling thermostat above ambient temp it shuts off - as noted. When you raise a heating thermostat above ambient temp it turns on...
Title: Re: What's this? (blower found in bay
Post by: Tom Lang on June 10, 2016, 11:17:03 pm
I suspect the original owner incorrectly added a heating thermostat. I'd bypass it so the OEM thermostat and fan can work as intended.
Title: Re: What's this? (blower found in bay)
Post by: prfleming on June 10, 2016, 11:23:22 pm
I suspect the original owner incorrectly added a heating thermostat. I'd bypass it so the OEM thermostat and fan can work as intended.
To set the record straight, what you are seeing here is original to the coach. I have the same model, two build numbers before this coach. We are original owners and have had this thermostat since the day we purchased the coach from FOT. Thanks Bob
Title: Re: What's this? (blower found in bay)
Post by: Tom Lang on June 11, 2016, 12:09:05 am
If I set it on 40 it keeps running. If I set it on 85 it cuts off.....
That sounds like a heating thermostat to me. Perhaps the wrong one was installed.
Title: Re: What's this? (blower found in bay)
Post by: bobnkathy on June 11, 2016, 12:19:41 am
If I set it on 40 it keeps running. If I set it on 85 it cuts off.....
Are you sure the fan is going off when you lower it? If so, then the wiring is reversed. Need to wire to low side instead of high side connectors. We had this when we first purchased our coach from the factory. That was only one problem, we had fan blades mounted backwards, two belt engines installed with the grove side up, the hoses going to air compressor reversed, the ECM not programmed to the transmission, and much more. I was told when the coach was started to be built in mid 2006 and they had some disgruntle workers and some coaches suffered their anger. Possibly starting to find some of the same issues. Are you finding the coach overheating (running at temps over 205) at times especially in warm weather or making a noise like ball bearings rolling around in the engine area when idling? Bob
Title: Re: What's this? (blower found in bay)
Post by: bobnkathy on June 11, 2016, 12:28:29 am
Are you sure the fan is going off when you lower it? If so, then the wiring is reversed. Need to wire to low side instead of high side connectors. We had this when we first purchased our coach from the factory. That was only one problem, we had fan blades mounted backwards, two belt engines installed with the grove side up, the hoses going to air compressor reversed, the ECM not programmed to the transmission, and much more. I was told when the coach was started to be built in mid 2006 and they had some disgruntle workers and some coaches suffered their anger. Possibly starting to find some of the same issues? Are you finding the coach engine overheating (running at temps over 205) at times especially in warm weather or making a noise like ball bearings rolling around in the engine area when idling? Bob
Title: Re: What's this? (blower found in bay)
Post by: brrving on June 11, 2016, 12:55:17 am
Doesn't it seem to you that the installed thermostat is an incorrect one - as Peter and the other Bob (Beerslayer) have mentioned, if it's to exhaust heat as we all believe, the fan should run whenever the temperature is above the setpoint and shut off below it Richard (Dixie Flyer) is reporting it's shutting off when he raises the setpoint, which is not what a cooling fan's thermostat should do.
This is a vent fan to pull heat out. Exact same setup on my '07. Set the T-Stat to 80.
Title: Re: What's this? (blower found in bay)
Post by: craneman on June 11, 2016, 12:58:25 am
If I set it on 40 it keeps running. If I set it on 85 it cuts off.....
That sounds like a heating thermostat to me. Perhaps the wrong one was installed.
If it is set on 40 it is trying to get the bay to 40 which would be making the fan run. When set on 85 it turns off as that is probably the temp in the bay. Same as turning air conditioning thermostat to 60 and air comes on until it reaches the setting.
Title: Re: What's this? (blower found in bay)
Post by: bobnkathy on June 11, 2016, 06:50:23 am
If it is set on 40 it is trying to get the bay to 40 which would be making the fan run. When set on 85 it turns off as that is probably the temp in the bay. Same as turning air conditioning thermostat to 60 and air comes on until it reaches the setting.
While that may seem the logical way it works, FOT did not set up this way. When set for 80 degrees, it should come on when the temp reaches that number. This is an item only found on newer coaches and may seem strange to owners of older models Bob
Title: Re: What's this? (blower found in bay)
Post by: John S on June 11, 2016, 07:44:39 am
I have one FT put in on my 01. I do not think it is only newer coached though my thermostat s a bit different.
Title: Re: What's this? (blower found in bay)
Post by: Roger & Susan in Home2 on June 11, 2016, 08:19:12 am
There is one of these in my 2001 U320 in the main storage bay. The inverter is in that bay and the AquaHot is next to it and vents heat into that bay. Excess heat goes into the bay where my fresh and waste tanks are.
Title: Re: What's this? (blower found in bay)
Post by: dixie flyer on June 11, 2016, 08:44:42 am
Okay this is what is happening with the fan. With the thermostat is set at a lower temp the fan cuts on. When set at a higher temp such as 85 - 90 the fan cuts off. When on, it seems the fan is pulling air out of the compartment exhausting it out of the coach through the silver hose connected to the fan. I have never seen anything like it, so it raised my curiosity as to what this could be.
Title: Re: What's this? (blower found in bay)
Post by: Roland Begin on June 11, 2016, 09:07:00 am
Works like an air conditioner, a heat exhaust fan.
Roland
Title: Re: What's this? (blower found in bay)
Post by: bobnkathy on June 11, 2016, 09:16:49 am
Okay this is what is happening with the fan. With the thermostat is set at a lower temp the fan cuts on. When set at a higher temp such as 85 - 90 the fan cuts off. When on, it seems the fan is pulling air out of the compartment exhausting it out of the coach through the silver hose connected to the fan. I have never seen anything like it, so it raised my curiosity as to what this could be.
It is definitely an exhaust fan. Apparently, it is wired in reverse. It should kick on when the temp reaches the set temp. Alton at FOT had to fix mine for the same reason you are having. He said that many were wired wrong. I took him all of three minutes to fix it. I does a great job exhausting hot air out of the compartment. Might need to get that fixed so it works correctly. Regardless of what others are saying, as an owner of the same model, two builds apart, your coach and my coach where on the production floor at the same time. That I know from FOT. So, it stands to reason we will experience similar problems for sure. Bob
Title: Re: What's this? (blower found in bay)
Post by: FourTravelers on June 11, 2016, 09:32:23 am
These thermostats are brain-teasers. To state Bob's explanation another way, when you turn "down" a cooling thermostat, it will turn on to attempt to reach the colder temperature requested. This is what Dixie Flyer said was happening. In summer temperatures the 40 degrees will never be reached without some type of additional cooling, so the fan would run continuously.
When you turn "up" a cooling thermostat, it will turn off when the temperature matches the ambient temperature (85 degrees in this case) - because cooling is no longer being requested. Again as Dixie Flyer stated was happening. When set at 85 degrees and fan off, if the temperature would rise above 85 degrees, the fan would turn on, as stated by Bob, to try to reduce the temperature back to 85 degrees, and then shut off again.
This is the way the kitchen Fantastic vent thermostat works, this is also a "cooling" thermostat.
Correct......... a cooling thermostat..... the fan can only cool the compartment to the ambient temp outside at best, if set too low it will run continuously without some type of cooling added. 80 to 85 should be fine
Title: Re: What's this? (blower found in bay)
Post by: prfleming on June 11, 2016, 09:48:34 am
This exhaust fan looks like a great idea! I added an inverter/charger in my center storage bay and it produces a lot of heat when charging and inverting. I have been leaving the bay door slightly open when camping, adding a blower will help.
I found the same thermostat that you guys have here - only $25:
Exhaust fan thermostat (https://www.zoro.com/columbus-electric-line-volt-mechanical-tstat-120-to-277vac-etd-5s-6s/i/G1179403/)
Here is a blower that should work - only $28. Easy project for next weekend!
Exhaust fan (https://www.amazon.com/Fasco-50747-D600-Centrifugal-Blower-Bearing/dp/B0099CFJW4/ref=sr_1_1?ie=UTF8&qid=1465652646&sr=8-1&keywords=Fasco+Centrifugal+Blower)
Title: Re: What's this? (blower found in bay)
Post by: FourTravelers on June 11, 2016, 09:55:30 am
I have thought about doing this also, the bay gets quite warm, mostly because the duct work for the generator radiator runs through the front corner driver side of the bay down to the underneath of the coach.
FT designed it this way so maybe its not really an issue?
Title: Re: What's this? (blower found in bay)
Post by: Beerslayer_24 on June 11, 2016, 10:09:34 am
Peter found what looks like the identical thermostat. The specs say it's a SPDT (single pole double throw) thermostat, that means it could be wired for either heating or cooling. It would be very easy to connect it incorrectly for a given application.
If the fan comes on with ambient temperature rise, then it is wired to cool.
Title: Re: What's this? (blower found in bay)
Post by: Darrell LeBeau on June 11, 2016, 11:40:20 am
I have it, and it vents to the outside thru the bottom of inverter compartment.
Title: Re: What's this? (blower found in bay)
Post by: Gary & Jeannie on June 11, 2016, 12:46:30 pm
Our 2005 has what I call a button thermostat mounted on the ceiling in the inverter/charger bay. A single switch electrical box was used with a solid plate cover with a whole drilled out for the thermostat to fit in. Works great and pretty simple which I like.
Electrical box is mounted to the ceiling.
Title: Re: What's this? (blower found in bay)
Post by: rbark on June 11, 2016, 12:55:05 pm
That's what our '03 has.
Title: Re: What's this? (blower found in bay)
Post by: Tom Lang on June 11, 2016, 12:55:16 pm
That is what my 2003 has. When the temperature is above the set point, the fan is on.