Coming off two bumper (full basket) catches, I was sanguine regarding the power cable intermittent that would reset the trap unless it was hanging from the trap just so. The cord to the trap runs across a patio, so passer’s by may kick or step on the cord from time to time. And, the wind also blows occasionally. I was recording the trap (this is the IOT instrumented Defender) and noticed occasional losses of network connectivity and reboots. I didn’t want to touch anything as long as the mosquitos were being caught in such numbers. I believe catching is more important than fixing.
Yesterday, the trap was in a fault that is the same as “no gas,” which is caused by low combustion chamber temperature. Upon startup, the trap reached only 42°C after about 3 minutes instead of between 110°C and ~125°C. The gas was only weakly igniting, a problem with the propane flow.
The tank was replaced only a couple of days ago. I purchased this propane at a store that sells propane by the gallon for $2.16. They typically put in 4.2 gallons to fill an empty 20# tank, and the cost is about $9, much less than the $20 my neighborhood hardware store charges. But the hardware store uses the side release screwdriver valve to release air, while this store uses some hose that supposedly sucks the air out of the tank. I was wondering if perhaps their method was not working correctly and I was getting some air in the tank interfering with combustion. Before delving into that and fiddling with the side valve, I decided to try what had worked a month before, but this time each step done independently and in order.
This time I tried five interventions followed by resetting the trap. Fortunately, I have to wait only about 3 minutes for a result because of the WiFi instrumentation and the smartphone MQTT client.
- I connected another power supply I was using with the backup Liberty trap, and it showed no sign of intermittency (hooray, an issue addressed), but after resetting the trap, there was no improvement.
- I banged on the regulator to unstick any parts that might be impeding the flow of gas. No effect.
- I used the Gas Reset tool. No effect.
- I then used a bicycle pump and pumped away in the hot sun. No effect.
- I then disconnected the trap and carted it around the house to the garage where my 12 volt electric automobile tire pump could have a go. I connected and ran the pump for about 5 minutes. The pump gauge read initially about 77 psi, falling to about 73-74 psi. Not a large change to indicate blowing away an obstruction. I then reinstalled the trap and it started perfectly!
I don’t know how or why this worked. There may be an obstruction between the valve and the nozzle, or the nozzle is getting a bit clogged. After the catch drops off, I want to disassemble the nozzle – valve assembly and inspect the valve output to nozzle pipe. Perhaps there is some gunk in there that expands with temperature, choking off the propane. I can’t imagine what that might be, though. Another mystery that will have to wait for mosquito downtime, which doesn’t show any signs of happening soon.
Happy as can be after nearly 2 hours directly under the hot sun with combustion chamber temperature of 127.4°C and an inside case temperature of 58.3°C.
Temp=127.4C (0) at 5:6354 F=1 I=0 G=1 S=1 E=0 T=58.3C H=4.7% M=11096 (209/1014:4887) R=45~140 B=0.0 V=3.1
And I have no evidence of air or contaminants in the propane from the new supplier. Although i cannot “exonerate” them, there is insufficient evidence of anything other than good propane in the tank.