New incubator done, problem with flexwatt?

[Courtney281]

So we've got it all put together and done and it looks great. I've built 3 racks so far using flexwat of 3 or 4 inches, so I know hat I'm doing. I've never used the 11 inch before though. But after I put it all together, when it reaches around 110-112 it starts making a strange vibration sound and you can feel it as well. Is that normal for 11inch flexwatt when it gets that hot? I know how to solder and everything is covered with electrical tape, I've double checked everything. But I have never had my small tape do this. It's doing it with both peices of 11 inch tape that are in there (one going down each sidewall) Any ideas on whats going on?

[Don]

I've never experienced that. Why do you need for it to get that hot?

[Courtney281]

Thats what the thermostat is doing. I have the probe hanging in the middle of the incubator, so it manages the temp of the incubator, not the temp of the tape

[Don]

I do the same and my tape doesn't get that hot. Are you using a fan to circulate air? How big is the incubator? I'm using an upright freezer and have only one strip of flexwatt down the back and two four inch fans. The fans are regulated so they don't spin too fast.

[Steve-J]

This buzzing can happen when flexwatt is touching metal and the thermostat is set to proportional. Which thermostat are you using? The newest herpstat has two different modes, dimming or pulse. The pulse mode is designed to work without buzzing in a situation where buzzing is occurring in the default "dimming" mode. Does this help? If it is an older herpstat then there are a couple other solutions.

[Courtney281]

It's a brand new Helix porportional thermostat (DBS-1000). We have the tape along the sides of a tru cooler (6.5 feet tall) which is made of metal. Is it dangerous if it buzzes?

[Courtney281]

I do the same and my tape doesn't get that hot. Are you using a fan to circulate air? How big is the incubator? I'm using an upright freezer and have only one strip of flexwatt down the back and two four inch fans. The fans are regulated so they don't spin too fast.

We have a fan on the top in the back and a fan on the bottom in the front to circulate the air

[snakesRkewl]

Cover the clips with electrical tape so the metal doesn't touch the walls of the inc?

[Courtney281]

We didnt use clips. We soldered it, and they are all covered with electrical tape

[Steve-J]

The buzzing is a form of interference called harmonic resonance, it's more annoying than dangerous. If you want to confirm this is what's happening, switch the thermostat to non-proportional (on/off) mode and the buzzing should stop.