High Temperature Cutoff Switch

[Barnt]

Since I grow in such a small area, if the ventilation fans fail the temperature will sky rocket. Not only will the plants be toast, but there would also be the additional fire hazard created from all the heat.

I'm just looking for something to kill electricity in case temps reach a high level such as 110. At this temperature, its fairly obvious that something is wrong and power should be killed. I found something like this on ebay but there is a flaw with this. Once the temperature is tripped and the power is killed, the device will allow power to come back on when it cools back down. I want something that acts like a breaker, once it trips, it has to be reset to check what caused the problem. Otherwise the cycle will repeat. It failed for a reason, will heat up, trip sensor, cool down, turn on, heat up, off..on..off...

Other people have suggested a thermostat and relay. Once again, I could see using the thermostat say on heating setting set to the highest temp (say 95F). This will mean that the thermostat will trigger on until the high temp is reached. The relay would then need to be wired to cut main power when high temp is reached. Once again though, this would just reset once the temperature cooled down again. Other problems would include not knowing what I'm doing ha

Any thoughts?

 

[Stay Puft]

You could use a "Latching" relay for this. (or latching circuit) Perhaps something like ebay Item number: 360016576700 ..?

You should configure the relay so it can only be reset by a power cycle or Push-button switch once an over-temp condition had been detected.
Regards,
Stay_Puft

some things to look at:
http://www.eleinmec.com/article.asp?24
http://www.enemythunder.com/latchrelay.html

Look like some other people have the same question:
http://wiki.answers.com/Q/Draw_the_..._relay_circuit_wired_to_operate_a_pilot_light.

 

[kaljukajakas]

A cheap thermal fuse will prevent a fire:

http://www.us-electronics.com/files/Thermalcutofffuses.pdf

 

[Stay Puft]

I like Kaljukajakas's idea.
His solution costs much less and is far less complicated.
Sometime I get derailed off of the KISS track.
Regards

 

[jocat]

cap controller HLC-1e, high temp shutoff and 20 minute delay to protect bulb when power goes on/off

 

[Bozo]

what a great idea makes me wanna build a high temp shut off just need time delay relay to add to circuit and you have high temp cut off with delayed restart
Thanks Kaljukajakas

 

[GrassNewb]

Actually you want the "CAP HLC-3e" High Temperature Shut-Down with 15 Minute ON Delay

* HLC-3e combines the functions of HLC-1 and HLC-2 to protect your lights from hot starts and your garden from high temperatures
* A high temperature shutdown provides insurance from crop damage due to high heat from ventilation and cooling problems
* HLC-3e senses a power interruption and will start a 15-minute delay to keep the light from trying to re-fire during the cool down period





I almost went this route before I found some nice "thermo switches" locally at an electrical supply place. They are a heavy duty 15amp device that you can incorporate into a circuit. If the temp reaches 110F the switch opens the circuit cutting of the power. When the temp drops, the thermo switch closes returning the electrical power.
Works similar to those fuses mentioned in the other posts but can be re used over and over.

 

[Barnt]

I like the idea of a thermalfuse, however the lowest cut off temp I could find was 70C (158F). Things will be toast by then. I want something that cuts off around 100.

The CAP-HLC devices wont work because they restart themselves. If there is a situation that the high temp trips, something must have failed. Granted the device turning things off and on wont hurt anything temporarily, but what if when I checked on them the lights were on and I thought nothing was wrong?

A thermostat with a latching relay sounds like it would work, except I'm space limited and a thermostat + big relay wont work for my small cab.

 

[ambr0sia]

The CAP-HLC devices wont work because they restart themselves. If there is a situation that the high temp trips, something must have failed. Granted the device turning things off and on wont hurt anything temporarily, but what if when I checked on them the lights were on and I thought nothing was wrong?

I use two CAP HLC-3e and absolutely love 'em. Your concern is largely mitigated by the fact that they have a "Temperature Exceeded" light on them that lets you know that something went wrong at some point. I actually like the fact that they wait 15 minutes and try again as it keeps me from having an extended period of unintended darkness at any given time.

 

[Rolldaddy]

Cap-hlc on has one outlet. How can someone use it on a panel that has 6 240v outlets.

 

[TribalSeeds]

Since I grow in such a small area, if the ventilation fans fail the temperature will sky rocket. Not only will the plants be toast, but there would also be the additional fire hazard created from all the heat.

I'm just looking for something to kill electricity in case temps reach a high level such as 110. At this temperature, its fairly obvious that something is wrong and power should be killed. I found something like this on ebay but there is a flaw with this. Once the temperature is tripped and the power is killed, the device will allow power to come back on when it cools back down. I want something that acts like a breaker, once it trips, it has to be reset to check what caused the problem. Otherwise the cycle will repeat. It failed for a reason, will heat up, trip sensor, cool down, turn on, heat up, off..on..off...

Other people have suggested a thermostat and relay. Once again, I could see using the thermostat say on heating setting set to the highest temp (say 95F). This will mean that the thermostat will trigger on until the high temp is reached. The relay would then need to be wired to cut main power when high temp is reached. Once again though, this would just reset once the temperature cooled down again. Other problems would include not knowing what I'm doing ha

Any thoughts?

The Titan Controls Zypher 2 has a hold option that will not restart until reset. The Cap controls dont have that option.
Im in a similar boat... I need to figure a way to do this without a lighting controller trigger. I just want to use a 20A circuit with a timer and hi temp shutdown. I dont think its possible to find a thermastat that will shutdown without bringing power back up once the temp has lowered again

 

[watts]

sentinel MDT-1.. will shut down lights and stay off until you figure out the problem and reset the timer to come back on.

 

[TURBD]

Is there a 240v one of these in west Canada?
Looking for options so my sparky can finish up.
Looking to not spend a fortune. The shut off will have to handle 8/10/12 lights. Starting with 8k but would like room to upgrade in the future without buying a new switch.
It will also be located in the grow room and have to trigger in the electrical room. I ran wires and a box from grow to panal before I drywalled. So it will be hard wired.
Partner told me he can have a guy a the hydro store make one for $400. I laughed. I am sure I can find a better solution here.
I searched and there is a million posts on this topic but it seems to be all 120v.
Thanks in advance guys.

 

[watts]

the MDT-1 is 120v, you plug into 120v outlet. the outlet on the top right of MDT-1 allows you to hook a sentinel 4 or 8 240v light controller to it. The light controller is hardwired to your electric.

 

[TURBD]

We made out own light controller. It's a custom panal.
So would wireing this to the trigger wire from the timer work?
I am sure the answer is yes but just to confirm.

 

[TURBD]

I should have took pics with the cover off. Not sure if this will help.

 

[watts]

im not sure if the mdt-1 will work with other controllers or just the sentinel hph4 and hph8. I think it will work with other controllers though. I'm looking into that anyways, if i find out i'll let ya know.

 

[TURBD]

Ok thanks man.
The grey box on the left with the cover on it has the stuff for the lights.
It's set up to run the 2 plugs up top for veg and the 4 plugs you see and there will be 4 more in the empty box below. There's only 1 timer hooked up right now above the grey box for the veg lights as the bloom side is still under construction.
Just want this shit done. It's been 3 months of construction.
Ran out of veg space weeks ago.

 

[gurnt]

I made a cheap one a 220 thermostat e bay FOR $ 3.75 AND a time delay relay .$ 6.01 just set at 85 shuts light off. Then when the room is back at 80 relay comes on then the light 5mi later light come on

 

[Rolldaddy]

Gurnt,

Would be so kind at to post the model number or a link to those 2 parts you bought on ebay?

Thanks,

RD