Proportional t-stat backup ?

I have my Helix set at 95 - It's plugged into a herpstat set at 92 - The heat tape are all plugged into the Helix - The helix will only reach 92, and will shut down when the herpstat hits 91.5 ?

Am I missing something here :confused:

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Originally Posted by BP's Rock

I have my Helix set at 95 - It's plugged into a herpstat set at 92 - The heat tape are all plugged into the Helix - The helix will only reach 92, and will shut down when the herpstat hits 91.5 ?

Am I missing something here :confused:

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The herpstat is shuting it down. The herpstat is reaching its set temp and doing it job not alowing it go any higher.

Set your herpstat to like 95 and the helix to 95 and see if it doesn't stop at 95.

Your back up should be set the same as the everyday one so if the everyday one goes out then the backup want let the heat surge.

Good question.

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Originally Posted by Freakie_frog

The herpstat is shuting it down. The herpstat is reaching its set temp and doing it job not alowing it go any higher.

Set your herpstat to like 95 and the helix to 95 and see if it doesn't stop at 95.

Your back up should be set the same as the everyday one so if the everyday one goes out then the backup want let the heat surge.

Good question.

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I guess I was looking at it in a different perspective, that of if the helix were to fail and drop temps, the herpstat would kick in at 92 - I did as you suggested and they are leveling off together - still waiting for them to hit 95 though.

Good answer - Thanks

Make sure the probes are in the same area of the tank also.. Good luck let me know if you need any more help.

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Originally Posted by Freakie_frog

Make sure the probes are in the same area of the tank also.. Good luck let me know if you need any more help.

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Both probes are side by side in the same rack - The racks are identical - I had to set the herpstat up to 96 to get a 95 reading off of the helix without one shutting down the other - I got some thermometers in the tubs - just gonna play with it till I get my temps stable again :rockon:

i personally wouldn't back up a proportional with another proportional! the voltage may vary to the stat and may cause some problems!! contact jeff at helix and dion at spyder robotics to see what they say. i would back up with a ranco. alot of controls need the proper voltage to work correctly and last longer.


vaughn

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Originally Posted by kavmon

i personally wouldn't back up a proportional with another proportional! the voltage may vary to the stat and may cause some problems!! contact jeff at helix and dion at spyder robotics to see what they say. i would back up with a ranco. alot of controls need the proper voltage to work correctly and last longer.


vaughn

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Good point - I've mailed them both and am awaiting their responses...

Seems like overkill anyway to back up a proportional with a proportional. The odds that a Helix or a Herpstat are going to fail are not that great to begin with and the odds of it failing "on" is even less. Use an on/off like a Ranco or Johnsons as a backup. For some interesting reading, Dion once explained it to me like this when asked what the odds are that a Herpstat would fail "on":

99.9% chance it will fail off, .1% chance it will fail on. The reason is:



Anything goes wrong with the probe and it will shut itself off. It has a 5 amp fuse inside which means if it was overloaded the fuse would fail protecting the unit and of course powering off. The only component that can cause it to fail in the ON situation is the Triac that controls the AC going to the heat device. When these fail they have a chance at failing in the on position. Many other thermostats use triacs rated at the max output. That is why you hear of so many problems with other companies because the worst enemy to electronics is heat and triacs generate their own heat and must be heat sinked. As the heat goes up an electronic component becomes less efficient so a triac rated at say 6amps may only take 6 amps before it heats up and could fail at less than the rated amperage. I designed the Herpstats for the long run. Instead of using a 50 cent 6amp triac all Herpstats use high quality 15 amp triacs that cost about a buck more. The difference is even when the heat goes up my triacs are well within range and since the fuse limits the amount of amperage to 5 amps my triacs are not stressed. To put it in easier terms the triacs I am using are rated for 1800 watts (15 amps x 120Vac) and the Herpstat is only pushing 500 watts or the Herpstat II at 700 watts. Sounds silly to save a buck on such an important component huh? These are the reasons I have never had a customer with this failure.



Could it happen? I suppose a lighting strike or bad brown out condition or line voltage problem could cause it. But we have taken every measure to prevent THAT specific failure. :^)



For your reference all proportional thermostats use a triac. Most non-proportional thermostats like Ranco and Johnson Controls use a relay. Relays can stick and cause the same situation. I always tell people that are really worried to buy a relay thermostat such as a Ranco and set it for 4-5 degrees above their desired temp (or whatever they feel safe at) and then plug the Herpstat or other proportional thermostat to the output of the relay thermostat and set it to the correct temp. Then if there is ever a failure in the on position the relay thermostat will continue to regulate the temps until the problem is resolved.

I was running the herpstat on the racks with no backup stat - The herpstat failed on me in the off position - I threw some cheap ESU's on each individual rack, sent in the herpstat, and ordered a rush delivery on the helix - Thats how I ended up with 2 proportionals.

I'm only pulling 120 watts on 3 racks, and have 2 stats that can both handle the job - Dion did, I must add correct the problem and return the herpstat promptly, however at the time I sent it in to him, the original herpstats were "out of stock", so If I needed a replacement I would have been SOL for a few weeks if he were not able to fix it. Hence why I sought another proportional at that point in time...

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Originally Posted by jglass38

Seems like overkill anyway to back up a proportional with a proportional. The odds that a Helix or a Herpstat are going to fail are not that great to begin with and the odds of it failing "on" is even less. Use an on/off like a Ranco or Johnsons as a backup. For some interesting reading, Dion once explained it to me like this when asked what the odds are that a Herpstat would fail "on":

99.9% chance it will fail off, .1% chance it will fail on. The reason is:



Anything goes wrong with the probe and it will shut itself off. It has a 5 amp fuse inside which means if it was overloaded the fuse would fail protecting the unit and of course powering off. The only component that can cause it to fail in the ON situation is the Triac that controls the AC going to the heat device. When these fail they have a chance at failing in the on position. Many other thermostats use triacs rated at the max output. That is why you hear of so many problems with other companies because the worst enemy to electronics is heat and triacs generate their own heat and must be heat sinked. As the heat goes up an electronic component becomes less efficient so a triac rated at say 6amps may only take 6 amps before it heats up and could fail at less than the rated amperage. I designed the Herpstats for the long run. Instead of using a 50 cent 6amp triac all Herpstats use high quality 15 amp triacs that cost about a buck more. The difference is even when the heat goes up my triacs are well within range and since the fuse limits the amount of amperage to 5 amps my triacs are not stressed. To put it in easier terms the triacs I am using are rated for 1800 watts (15 amps x 120Vac) and the Herpstat is only pushing 500 watts or the Herpstat II at 700 watts. Sounds silly to save a buck on such an important component huh? These are the reasons I have never had a customer with this failure.



Could it happen? I suppose a lighting strike or bad brown out condition or line voltage problem could cause it. But we have taken every measure to prevent THAT specific failure. :^)



For your reference all proportional thermostats use a triac. Most non-proportional thermostats like Ranco and Johnson Controls use a relay. Relays can stick and cause the same situation. I always tell people that are really worried to buy a relay thermostat such as a Ranco and set it for 4-5 degrees above their desired temp (or whatever they feel safe at) and then plug the Herpstat or other proportional thermostat to the output of the relay thermostat and set it to the correct temp. Then if there is ever a failure in the on position the relay thermostat will continue to regulate the temps until the problem is resolved.

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Great Explanation Jamie! :rockon:

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Originally Posted by lord jackel

Great Explanation Jamie! :rockon:

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Thanks but that is all Dion at Spyder Robotics. The man knows a lot about thermostats! Herpstats are an excellent product!

helix is also a good product! :D



vaughn

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Originally Posted by kavmon

helix is also a good product! :D



vaughn

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Nobody said they weren't! :P

i just got to show my support!


after all helix pays me extremely well to give them props and recommend them :rolleyes:

they will even drop ship, and not make me order the minimum quantity. :cool:

after i sell a million units, i get a free 1500 watt system!!:carrot:

ps, this is all a joke, just messin around, a little humor. please don't call helix or sue me!


vaughn

Quote:

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Originally Posted by kavmon

i just got to show my support!


after all helix pays me extremely well to give them props and recommend them :rolleyes:

they will even drop ship, and not make me order the minimum quantity. :cool:

after i sell a million units, i get a free 1500 watt system!!:carrot:


vaughn

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I like it! I need to get paid for my opinion! :)

Helix drop ships for you? Awesome!! :sunny:

I was neither promoting, or demoting one T-Stat over the other - I've read the %'s of one or the other failing in on or off mode, and the %'s of them failing at all - These are both higher end T-Stats, and with the name and price you pay, they can still fail.


As I posted above, the herpstat did fail on me, and was sent in for work, repaired, and sent back promptly - This was back in early FEB of this year, with only 4.5 months on the new T-Stat.

At that time, herpstats were "Not in stock".

So I had nothing to work with except for cheap stats, and ordered the helix - Which has worked fine from day one - The herpstat is working fine now as well.

What I'm suggesting is that, why back up with yet a 3rd on/off T-Stat such as the ranco or johnson -when I have 2 proportional thermostats, that can indepenently in and of themselves handle the wattage I'm looking for, and not be used in conjuntion with one-another .

Quote:

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Originally Posted by kavmon

i personally wouldn't back up a proportional with another proportional! the voltage may vary to the stat and may cause some problems!! contact jeff at helix and dion at spyder robotics to see what they say. i would back up with a ranco. alot of controls need the proper voltage to work correctly and last longer.


vaughn

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Here are the replies I've received - 1st from Jeff, secondly from Dion.

Hello, It is up to you, I would think a on/off or off/on thermostat would be more suited, as the DBS-1000 is digital. I imagine some people will have a back up for the back up too...Also my opinion is that a back up is needless overkill. In 9 years of using them and talking to thousands of customers big and small, The Helix DBS-1000 has proved extremely reliable. The only condition That a back up would be coming into play is if the DBS-1000 probe is moved away or left away from the heat source during cleaning. Or if multiple cages are used and the probe's heater is not super reliable, and failed. In this case you could have a back up with the probe in another cage incase the probe's heat source failed and the DBS-1000 probe could not see any heat.
The DBS-1000 system has safety failsafes built-in for every other condition.
I understand after people experience losses with cheaper under-par thermostats they need extra assurances, however unnecessary,That's understandable.
Thanks for thinking Helix, Jeff Washburn


Mike,

The Herpstat can be used as a backup thermostat if you do the following:

VERY IMPORTANT: Plug the Herpstat up by itself and follow the manual to set
it to NON-PROPORTIONAL MODE

Then set the Herpstat temperature a couple of degrees above your target
temperature that will be set on the proportional stat.

Then plug the proportional thermostat up to the output of the Herpstat and
attach the rest of it as normal.

Only a Herpstat proportional thermostat can be used as a backup thermostat.
Other proportional thermostats do not have non-proportional mode and can
cause damage if they dim while another thermostat is attached to their
output. Not sure if you saw my article on the website posted here:

http://www.spyderrobotics.com/support/failsafedocument.html

In my experiment I used a cheap sub $30 zoo med thermostat as the backup and
it worked great. The ranco/johnson controls is the "best" setup though
since they use a relay to control the AC the produce little to no heat from
their electronics. You can find those in the $50 range. All depends on how
much your trying to protect. If you have a $1000 plus animal an extra $50
worth of protection isn't a bad idea. :^)

-Dion