Auto mag control

[timberr]

So I have been thinking about how to make my system double redundant. Currently it has a battery backup which will run the system for 5+ hrs, so I am covered for loss of power. I also have a Honeywell aqua stat for high temp protection (circulates water through storage). I have contemplated adding a dump zone but only being a "basic" electrician was unsure with with how to incorporate both an Auto-mag (for power failure) and Zone valve to auto siphon for high temp protection. While walking the dogs it hit me and think I have found the solution.

I could use a Tekmar 150 and A auto mag. I would put the temp sensor on the boiler, the Tekmar 150 would have a setpoint of lets say 200*. When the boiler is below 200* the auto-mag would be energized and stay closed if either the power goes out or boiler get's over 200* the Auto mag is de-energized and it opens allowing for auto siphon.

Sound right?

 

[jebatty]

I think any open on rise type control would work, mechanical aquastat, Ranco, Tekmar, etc. I use a mechanical aquastat set at 210F. It might be useful to setup a control so that when the automag opens (power loss or overheat), a circulator also is powered on and the dump zone then will function as a fully operable zone rather than just by gravity.

I also have a UPS battery backup on my system. I replaced the two internal 12v - 7ah batteries with two 12v - 105ah batteries which will power the system for about 4-5 hours to a 50% battery draw-down.

 

[dogwood]

Jim, what mechanical aquastat do you use? I'd like to get one. I don't know what term "mechanical" refers to in an aquastat to tell the truth.

Mike

 

[goosegunner]

Couldn't you just put a normally closed contact Rib relay between your overheat circuit and your automag?

Then if overheat circuit is energized it would open the contact and automag would lose power. or if Power was lost the automag would open.

gg

 

[dogwood]

Excellent suggestion Goosegunner.

Mike

 

[goosegunner]

Excellent suggestion Goosegunner.

Mike

Thanks now I just need to add it to my system. I have been going to do it for a while just haven't done it yet.


Gg

 

[mikefrommaine]

Couldn't you just put a normally closed contact Rib relay between your overheat circuit and your automag?

Then if overheat circuit is energized it would open the contact and automag would lose power. or if Power was lost the automag would open.

gg

It's early but, if you did that would the n/c relay be energized every time the zone thermostat called for heat?

 

[jebatty]

timberr: I also have a Honeywell aqua stat for high temp protection (circulates water through storage).

What Honeywell aquastat to you have? Perhaps a L4008B? This is the mechanical type of aquastat I mentioned. The L4008B is SPST. If the voltage it is switching and the voltage of your Automag are the same, it can control both. I assume that the high temp aquastat cuts power to your draft fan at the high temperature setting. It similarly could cut power to the Automag by wiring the Automag in parallel with the draft fan. If the voltages are different, then a relay with coil voltage the same as the voltage being switched for the draft fan voltage could be used, as goosegunner mentioned, with similar parallel wiring. Coil would be energized along with the draft fan, and on overheat when the draft fan power is cut the Automag power also would be cut, causing it to open. Also, on power loss the coil is de-energized, causing the Automag to open.

 

[timberr]

I see that you all missed on key point "BASIC" electrician. If I remebered I fried (5) 24V power supplies wiring my system before I discoverd a power suply with a circut breaker. I can't remeber the model of my aquastat, it is a strap on model. Currently set for 200* when that temp is hit the boiler circ activates. I willl leave that inplace so when the automag opens the circ will be running.

As mentioned before this is my failsafe option. My backup inverter with built in charger and transfer switch has worked flawlessly for 2 years (approximately 12 times it was needed).

Sounds like this will work for us simpletons.

Thanks