compressor is heating up to the point it blows hose

[vhcook]

Originally Posted by tickspe15

We use a different type of tube coming off the compressor that is rated for higher temperature operation. I believe the tube we use is rated for 200+ degrees Fahrenheit compared to the KOP tubing which is rated for 120ish degrees. We have also experimented with a metal sheathed tube coming off the compressor but higher rated tube seems to work just as well and be much lighter.

Could you provide a part number/source for this high-temperature-rated tube?

[Jaxom]

Originally Posted by tickspe15

We use a different type of tube coming off the compressor that is rated for higher temperature operation. I believe the tube we use is rated for 200+ degrees Fahrenheit compared to the KOP tubing which is rated for 120ish degrees. We have also experimented with a metal sheathed tube coming off the compressor but higher rated tube seems to work just as well and be much lighter.

Don't forget that the pressure relief valve (calibrated to 125 psi or lower) must be connected to the compressor via hard fittings (R67.B, R76). If your compressor only has one port you're going to have at least one tee on it; might as well make it brass and get some heat sink value.

[Ether]

Originally Posted by Team3844

Last year our compressor ran nonstop during matches but we had no problems with blown hoses.
We just started having this problem after weeks of problem free pnematics on our practice bot.
Does anyone have an idea how to dissipate the heat?

Do you have the plastic hose connected directly to the fitting on the compressor?

[Dunngeon]

Originally Posted by Team3844

Last year our compressor ran nonstop during matches but we had no problems with blown hoses.
We just started having this problem after weeks of problem free pnematics on our practice bot.
Does anyone have an idea how to dissipate the heat?

Are you running the VIAIR 90 C? We too had this issue, for the practice bot we switched the compressor to a Thomas 215 which is rated for 100% duty. We retained the 90C for the competition bot because it only needs to run in short bursts.

[ArtemusMaximus]

Originally Posted by Dunngeon

Are you running the VIAIR 90 C? We too had this issue, for the practice bot we switched the compressor to a Thomas 215 which is rated for 100% duty. We retained the 90C for the competition bot because it only needs to run in short bursts.

Correction: Thomas 215 may be better in some regards but it definitely is not rated 100%, it's actually rated only @10%/100psi (Link)

Check this last year thread
http://www.chiefdelphi.com/forums/sh...d.php?t=129321

To my knowledge only these 3 compressors are 100% duty and FRC legal (at least according to 2014 rules)

• Thomas 405ADC38/12
• Thomas 415CDC30/12
• Viair 250C-IG

See comparison list I compiled last year http://www.chiefdelphi.com/forums/at...1&d=1399302557

[rich2202]

When they say "10% Duty Cycle", over what period of time is the 10%? 2.5 minutes on (for a match), and 22 minutes off?

[ArtemusMaximus]

Originally Posted by rich2202

When they say "10% Duty Cycle", over what period of time is the 10%? 2.5 minutes on (for a match), and 22 minutes off?

Compressor doesn't just work 2.5 minutes on the field. I don't know any team that would let their bot to go on the field with empty stomach .. uh .... I mean empty air tanks. Then it has to work during match. Times between matches are sometimes less than 20-30 minutes. Some of the times is used to adjust bot system and running tests, meaning more compressor usage. No wonder that number of teams have compressor overheating issues.

You cannot call it 100% duty cycle. Besides being incorrect, it is very misleading.

Comparing apples to apples, Viair 90C is 9% Duty cycle, just 1% less than Thomas 215. Which means that difference is marginal.

Having even small fan cooling off compressor will make more impact than switching from Viair 90C to Thomas 215. Especially considering that Thomas 215 is 3 times more expensive that Viair 90C. If you can spare 4 pounds on you robot Viair 250C-IG is much better choice for less money.

[AdamHeard]

Originally Posted by ArtemusMaximus

Compressor doesn't just work 2.5 minutes on the field. I don't know any team that would let their bot to go on the field with empty stomach .. uh .... I mean empty air tanks. Then it has to work during match. Times between matches are sometimes less than 20-30 minutes. Some of the times is used to adjust bot system and running tests, meaning more compressor usage. No wonder that number of teams have compressor overheating issues.

You cannot call it 100% duty cycle. Besides being incorrect, it is very misleading.

Comparing apples to apples, Viair 90C is 9% Duty cycle, just 1% less than Thomas 215. Which means that difference is marginal.

Having even small fan cooling off compressor will make more impact than switching from Viair 90C to Thomas 215. Especially considering that Thomas 215 is 3 times more expensive that Viair 90C. If you can spare 4 pounds on you robot Viair 250C-IG is much better choice for less money.

Eh, I'm not sure I trust Vair specs NEARLY as much as Thomas specs.

[Mr V]

Originally Posted by rich2202

When they say "10% Duty Cycle", over what period of time is the 10%? 2.5 minutes on (for a match), and 22 minutes off?

I don't know what the maximum on time is for the Thomas but somewhere I saw that the Viar was rated for a max on time of 3min. So a ~30 sec initial charge time, a few minutes of rest, 2.5 minutes of cycling on and off during the match and ~30 minutes between matches puts it in its intended duty cycle.

Originally Posted by AdamHeard

Eh, I'm not sure I trust Vair specs NEARLY as much as Thomas specs.

Personally the fact that Viair rates theirs at 9% makes me trust their specs more and the fact that Thomas rates theirs at 10% makes me suspicious of their specs. Fact is that real world numbers rarely come out so nice so Viair advertising 9% makes me think it is based on actual data determined by real world testing w/o rounding it up to 10% which would look better on the data sheet.

[Team3844]

Moved all of our metal fittings down to the compressor for the heat sink value today. It fixed the problem with the added help of throwing more ballast to the back of the robot.
We did discover one trick that we did last year without knowing how it helped.
We used a plastic elbow push fitting as the first non metal fitting last year. The extra heavier thermoset housing helped isolate some of the heat before it got to the tubing.

[Team3844]

Thanks for all the replys. We learned a lot from going through them with the team.

[ArtemusMaximus]

Originally Posted by Mr V

I don't know what the maximum on time is for the Thomas but somewhere I saw that the Viar was rated for a max on time of 3min. So a ~30 sec initial charge time, a few minutes of rest, 2.5 minutes of cycling on and off during the match and ~30 minutes between matches puts it in its intended duty cycle.



Personally the fact that Viair rates theirs at 9% makes me trust their specs more and the fact that Thomas rates theirs at 10% makes me suspicious of their specs. Fact is that real world numbers rarely come out so nice so Viair advertising 9% makes me think it is based on actual data determined by real world testing w/o rounding it up to 10% which would look better on the data sheet.

Spec sheet for Thomas states 3 minutes on - 30 minutes off @ 23°C
http://www.gd-thomas.com/workareasho....aspx?id=24872

[Al Skierkiewicz]

Art,
Can you tell us which compressor you are using?

[ArtemusMaximus]

Originally Posted by Al Skierkiewicz

Art,
Can you tell us which compressor you are using?

Ah, I am not part of the team this year (few different reasons). So I am not using anything this year. Last year we were using only standard equipment that came in a tote (Viair 90C). But I did a research last year and if you remember you contributed to this thread http://www.chiefdelphi.com/forums/sh...d.php?t=129321. If i'd be still on the team I would insist to use VIAIR 250C-IG. It just make sense to me

In this thread I stepped in to address the statement that Thomas 215 had 100% duty cycle, which I knew was incorrect.

[Al Skierkiewicz]

Art,
Sorry, I was speaking to the OP, Arthur Canada.
There seems to be four compressors that everyone is using these days.
The original Thomas 415 which is heavy but a great work horse. (Top and side ports are legal)
The Viair 90C (The top port is not legal for FRC and the nickel plated check valve must be in place.)
Viair 250 (The included stainless steel hose must be attached for FRC rules)
Thomas 215 (the top and side ports are both legal to use and this compressor does not require an external check valve)

The two small compressor run very hot as there is little thermal mass to absorb the heat generated. External cooling can be applied provided no modification to the compressor is made. (Do not use the screws to mount other devices.)