Homemade Cabinet Incubator Thermostat & Humidity Options

[badflash]

65% is fine for hatching. No worries.

 

[badflash]

At day 6 into the test run the controller started to behave erratically and would start doing 5-8 degree C high temperature excursions. The eggs are obviously dead at this point.

I was also using a WH8040 humidity controller that uses relay outputs. When the WH8040 reaches the turn-off point the relays chatter many times before turning off the humidifier. I think the pulses damaged the temperature controller in some way. I've ordered a replacement.

In the mean time I've found a nice work around. I disconnected the humidity controller and have it run all the time at nearly the lowest setting. It is pretty easy to maintain the humidity where I want it manually, so for now, manual will it will be.

The REX-C100F can be operated in On/Off mode. If you set the proportional band to 0 the Integral function becomes hysteresis setting. Set that to 0, and set digital filtering to 0. I found that the heater would cause the temperature to overshoot by about .9 degrees C, so I put a light dimmer in series with the SSR. Now it cycles between -.1C and +.2C about every 3 minutes. This works for my application.

 

[WalnutHill]

At day 6 into the test run the controller started to behave erratically and would start doing 5-8 degree C high temperature excursions. The eggs are obviously dead at this point.

I was also using a WH8040 humidity controller that uses relay outputs. When the WH8040 reaches the turn-off point the relays chatter many times before turning off the humidifier. I think the pulses damaged the temperature controller in some way. I've ordered a replacement.

In the mean time I've found a nice work around. I disconnected the humidity controller and have it run all the time at nearly the lowest setting. It is pretty easy to maintain the humidity where I want it manually, so for now, manual will it will be.

The REX-C100F can be operated in On/Off mode. If you set the proportional band to 0 the Integral function becomes hysteresis setting. Set that to 0, and set digital filtering to 0. I found that the heater would cause the temperature to overshoot by about .9 degrees C, so I put a light dimmer in series with the SSR. Now it cycles between -.1C and +.2C about every 3 minutes. This works for my application.

I am using the STC1000 and my swings are 0.4 C max at the sensor; the independent "memory" thermometers in the incubator read a rock steady 100F as long as I don't open the cabinet for long or add cold or hot water to the pan.

My WH8040 has never done the chatter you describe, but my load is a mini aquarium pump designed for a 1 gallon tank.

 

[badflash]

Chatter has nothing to do with the load. You are lucky with yours. The chatter problem is widely discussed with this units.

When I used the STC1000 last year my swings were over 1 degree C and my hatches were a failure.

I'm pretty happy with the performance now that I have the light dimmer set up with the narrow band on the on/off controller. I have it dialed in to +/1.2 degrees C. Now to see if I hatch any birds.