TPMS Alarm Setpoints

[etojeo]

I just purchased and installed a TST TPMS system for our 28 International. So far, so good - love it.
We are on our first trip and I was surprised at the tire temperatures and somewhat surprised at the pressure gains too...
The ambient temperature was 84 - 85F and starting tire pressure was at 78 PSI for all four tires. I saw tire temps up to 95F and pressures up to 89 PSI.

The question I have is - where do you set your temperature and PSI Alarm set points? I'm wondering what I will see on those days where I'm running with temps in the upper 90s...

Thanks

[Julie-Bob]

Originally Posted by etojeo

I just purchased and installed a TST TPMS system for our 28 International. So far, so good - love it.

We are on our first trip and I was surprised at the tire temperatures and somewhat surprised at the pressure gains too...

The ambient temperature was 84 - 85F and starting tire pressure was at 78 PSI for all four tires. I saw tire temps up to 95F and pressures up to 89 PSI.



The question I have is - where do you set your temperature and PSI Alarm set points? I'm wondering what I will see on those days where I'm running with temps in the upper 90s...



Thanks

Per the TST manual The tire temperature is pre set at 158 Degrees (F). The manual states that on the low side set the alarm at 10% below the your normal PSI. On the high side set the alarm at 25% higher than your normal PSI.

Hope this is helpful

[FishByFly]

Today, we drove in 100 degree outside temp with tire temps about 108 on the side facing the sun and 104 on the shade side. The starting pressure in the tire was 65psi and we saw pressures at this peak temps about 78psi.

Used all the TST recommended set points.

[Baby Zeppelin]

When we first got the our trailer we had the pressures set at 80 psi with the TST unit set at the recommended points. Later we reduced the pressures to 65 psi cold and they worked with me over the phone to recalibrate the unit. Very helpful folks.

[etojeo]

Bob -
Thanks, you are correct on the manual and I have set the PSI at 25% above my 80PSI at 100 PSI alarm point. I err'd on asking the temp question....

Per FishByFly PSI escalations (based on his 65 PSI starting point), it doesn't seem like I will alarm at hi pressure - something I'd like to avoid to just skip any unnecessary drama... But I'm thinking I will be darn close to 100 PSI on a hot day here in the Carolinas!

[Julie-Bob]

Originally Posted by etojeo

Bob -

Thanks, you are correct on the manual and I have set the PSI at 25% above my 80PSI at 100 PSI alarm point. I err'd on asking the temp question....



Per FishByFly PSI escalations (based on his 65 PSI starting point), it doesn't seem like I will alarm at hi pressure - something I'd like to avoid to just skip any unnecessary drama... But I'm thinking I will be darn close to 100 PSI on a hot day here in the Carolinas!

We are running Good Year Endurance. Book calls for a max of 80 psi The we have loaded our trailer (we weighted) we run 65 psi per the TST. We live in Phoenix and see 115 degrees days. So the temp and pressures are watched all the time.

[Cap-N-Red]

The people at TST are very good about working with you, Incase you have a problem or a question. Just give them a call.
I say a big THANK YOU , to them

[KK4YZ]

I recall one of the tire experts saying to expect a roughly 15% increase in pressure from cold inflation to running pressure. It may go a little higher for the tires on the “sunny side”. Keep in mind that the tire inflation specs refer to COLD inflation pressures. Operating pressures are expected to be higher.

What you’re really trying to accomplish with the TPMS is to get an early warning of a slow leak (nail, etc) that, if left unaddressed, will result in the tire coming apart and damaging the trailer. I have my “low pressure” limit set to about 10 PSI below cold inflation pressure. That will accomplish the task and eliminate false alarms.

I’m not sure what failure mode the high pressure limit is intended to address.

I guess the “high temp” limit is used to detect a problem at the hub (bearing failure?).

Maybe one of the tire experts can chime in.