Herpstat 1 odd?

[spinytail12]

I don't attach my probe right to the heat tape. I cut a 2"x 2" piece of plastic from a old tub and put that between the heat tape and the probe.it keeps the temps steady. Directly on the tape seemed to cycle constantly. I also taped the cord and left the probe itself open.

Shane

[AdamL8]

It's right back to doing the same thing again even though I only have masking tape on the cord and the very tip of the probe. It's running as if it were an on off going full power to no power. It worked fine the past few days until last night so suffice it to say that I am thoroughly confused.

[AdamL8]

I emailed Dion about it so hopefully he has seen this issue before and knows what is causing it.

[MarkS]

What do you use to hold your probes on? Aluminum tape was just what I had seen other people use before and made sense as I would think that it would take in more of the heat from the heat tape and not from the air temp.

I use duct tape. It's non-conducting and is designed for high temperature applications.

[AdamL8]

I thought about using duct tape but masking tape seemed like it would be even less conductive. It clearly isn't doing anything so I will switch to the duct tape right now and see if it changes at all.

[kitedemon]

eletrical tape most are rated to 90ºC (194) flame retardant and designed to do what you are trying to do it is made for the job.

[spyderrobotics]

Adam,

I got your email this morning and wanted to answer the question here in case anyone else was curious. Everything in your symptoms shows that the thermostat is working properly. Your heating device is struggling to maintain your setting of 99.0 degrees. In your email it listed the room temperature swings from 80 and drops down to 70. For some heating devices (and depending on probe placement) it may be difficult to reach your 99 degree setting with the room temp at 70. This is not a fault of the thermostat. What is happening is the thermostat is determining how much power it takes to reach and maintain your target temp. When you did the master reset you are clearing its learned power curve. This clearing also happens if you enter the menu or if the device is unplugged. The device will then slowly work its way up to the target temp. When it gets two degrees below target temp it will start figuring out a curve. Every cycle if the temp is below your setting it will bump the power up a percent. If the device overshoots the target temp then it will bump the power down a percent. In your case it had to continue bumping the power up to 100% to keep close to the target temp. Once it goes over the target it shuts power off which is designed. The object is to stay as close to target without overshooting by much. In your case this is providing regulation 98.7 to 99.1 degrees. This is excellent regulation! I wouldn't suggest changing anything unless you started seeing the temps drop too much in which case you would need to keep the room consistently warmer or upgrade the heating device to a higher wattage. Now if you had a hot room or a overpowering heating device your would see those numbers backing down and not staying at 100%. Hope that helps clear things up.

Dion Brewington
Owner, Spyder Robotics

[AdamL8]

It actually goes up to 99.7 but that still isn't bad at all. I figured that it had something to do with the devices learning curve but I wasn't sure if that would sound stupid. It stays just about perfect on the temperature either way. Thank you for the quick response.

[spyderrobotics]

It actually goes up to 99.7 but that still isn't bad at all. I figured that it had something to do with the devices learning curve but I wasn't sure if that would sound stupid. It stays just about perfect on the temperature either way. Thank you for the quick response.

I could see 99.7 on initial regulation. Once its been running for an hour I would think that would settle down some. If not then by changing the probe position to be closer or farther away from the heating device will affect the overshoot so with a little experimentation you could probably minimize the overshoot.

Always happy to help!

-Dion