New incubator done, problem with flexwatt?

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?

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

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

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.

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.

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?

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Originally Posted by 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.

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

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

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

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.

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Originally Posted by 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.

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Thank you for your help. I would try that, but its not the kind you can switch on and off. But as long as I know it's not dangerous, Im good. Thanks again

I may have overlooked something important, I hope you check back on this thread. Is your helix grounded or not? If it is not then you may have to ground the metal surface for safe operation. Sorry I neglected to mention this earlier.

we didn't get the grounded helix, but it is plugged into a grounded power strip

It is possible that you may need the grounded version of this Helix for your incubator project to ensure the safest operation. If that is not a option then you may have to manually ground the system.
To ensure safety you may want to test the flexwatt by plugging it in to the wall without the thermostat for a few moments (not for long) just to hear if it still buzzes without the thermostat. If there is no buzzing when plugged in directly then it is likely due to the proportional style of heat control or the grounding issue. If the flexwatt buzzes even when it is plugged directly into the wall, then it's likely wiring or grounding and not related to the proportional style of heat control.

How do we manually ground it? I've never had to do that before, wouldn't know where to begin

Having the grounded helix isn't going to help in this case, all the ground on the grounded helix does is ground the helix itself. what you need to do is ground the incubator itself. This is very easy to do,

start by drilling a small hole on one of the metal surfaces (any metal surface that comes into contact with the flexwatt)

this hole will be for a metal machine screw to go through (like this but shorter)

http://i1186.photobucket.com/albums/...1ME90_AS01.jpg

the screw needs to fit the hole tightly.

The screw will have a nut on one end and will be used so attach a wire.

It will look something like this (but with only one wire)

http://i1186.photobucket.com/albums/...ing_system.jpg

The other end of the wire will need to be attached to something that is grounded (you could modify an extension coed so the wire screwed into the cage taps into the ground on the extension cord but there are many ways to do this)