Tekmar Sensor & High Limit..

ChasMan

That's a great picture thanks. I love that piece of rigid conduit with the bushing on the end. Now I need to find some chrome conduit!

ChasMan

Tekmar Outdoor Reset vs. High Limit.

New Control, Old Boiler.. The Manual says to use the tapping #7 for the high limit sensor... Ok, well Aquastat came out of that.. Now high limit is in, where do I put the boiler temp sensor for the Outdoor reset? Strap it to the pipe?

Al Letellier_9

tekmar sensor

You didn't give any info on boiler or control so tapping #7 means zip on this end, but yes the boiler temp sensor usually gets strapped to the supply pipe at the point of system temp. Read the instructions that come with the control. The sensor comes with tie to hold it in place, and make sure to insulate over the sensor, as shown in the instructions.

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Rodney Summers

I prefer a well

Might be a hassle but a "T" in the supply pipe would give the beast temp reading.

ChasMan

Hmmm

Well, I have no issue with strapping it to the pipe as shown in the docs. I just didnt think that the supply pipe would be anywhere close to the temperature that the high limit is reading stuck in a well in the middle of all the water. But if thats a good spot, then thats where it goes. If anyone has a pic Id appreciate it :-)..

Unknown

Picture

Here is a picture of my Burnham MPO with the Tekmar Reset Control Supply Senser in a tee in the supply main. It is held into the immersion well with a clip that is supplied with the well. You will get a much more accurate response and reading with it in the well immersed in the flow of the system main. Hope this helps.

Glenn Stanton

Manager of Training

Burnham Hydronics

U.S. Boiler Co., Inc.

Robert_15

Hi Glenn I am going to put the senser in the supply. i do relize that the ideal location would be after the bypass put it would seem to me that the temp. would be much cooler because of the bypass water coming through. i have right now is a tee off the top of the supply (looks like yours)with a purge valve i would replace that with what you have. less then a foot is another tee that has the bypass coming into it then from there it all goes to the system. do you think that would work?
Scott
sorry wrong post

Unknown

Scott

Unless you have the sensor out in the system flow after the bypass, then you will not get a true reading of the system temperature. You will be monitoring boiler water temperature that is blending with the bypass water. This will result in much cooler water temperature in the system due to the sensor being satisfied prematurely by the hotter boiler water.

Glenn Stanton

Manager of Training

Burnham Hydronics

U.S. Boiler Co., Inc.

ChasMan

Just another thought.

How will the sensor read the boiler temperature corectly if all the zone valves are closed and no water is flowing?

Robert_15

glenn

Ok then i will put it after the bypass. there is a elbow just after the expantion tank but before the circulator would that be ok to put there? the reason is after the circulator the pipe is redused to 3/4 copper i was thinking that the 1 1/2 steel pipe would offer more room for the probe & water flow. if not there is no elbow after the circulator just streight copper pipe before the zones split. if you think it will not i will try to put it after the circulator
scott

Unknown

No Flow

When there is no flow or no call for heat, then the boiler would be off. A reset control is intended to be used on Cold Start applications only. When there is a call for heat, they make a "system" water temperature. When there is a call for DHW, they boost to a temperature neccessary to satisfy the indirect heater. No temperature maintainance or tankless heater applications with a reset control. It defeats the purpose.

Glenn Stanton

Manager of Training

Burnham Hydronics

U.S. Boiler Co., Inc.

Unknown

Chrome

You can have anything Chrome Plated for a price!

Glenn Stanton

Manager of Training

Burnham Hydronics

U.S. Boiler Co., Inc.

Rodney Summers

It depends

I think if you put 10 or 15 sec delay fire on the Tekmar, it will start the circulator first so some heated water should get to the sensor so it doesn't fire the burner and then shut it off 5 seconds later since it realizes the water is still within the targeted temp.

ChasMan

Ok, I get it now, that was my confusion. So with the reset there is no concept of low / high just how hot is it now! Thats excellent, makes it much more simple to deal with in my head now.

Rodney Summers

Hey Glenn

Any issues with putting a Tee in the P/T tapping and putting a long well into the boiler for the sensor and piping the P/T valve off the side of a 3/4" Tee? I like to do this for Tekmar add on jobs rather then opening up the supply piping. Temp usually lags a little behind but I still think it's beter then strapping a sensor to a side of a pipe. Only issue might be if there's an air bubble in the boiler.

Joe Brix

Not really

Min temp is needed for the outdoor reset to calc a temp curve. You usualy don't want to pump water below 140° as this could cause condensation in the boiler. Copper fin baseboard and hydro air handlers might not even heat the space below a set temp.

ChasMan

Ok, thats what I thought, but, with the sensor in the supply pipe and the boiler shut off, and no call for heat, the temperature will drop to zero. So, then when there is a call for heat, cold water will circulate.. Yes? No?

Rodney Summers

My Tekmar 260

will start the circulator at any temp. Might not be the best thing to do. Better to wait for boiler to come up to min temp, but some boilers want flow while firing.

During heating season or just to fire up the indirect, the boiler never gets down to room temp. Plus I still have the aquastat on the boiler keeping the low limit of 120°

Rodney Summers

Glenn, what kind of wire is the black stuff from the reset?

Glenn, what kind of wire is the black stuff emanating from the reset box?

i have a similar setup to yours & am using a combination of ac(bx) & "firewire" (ul alarm wire for fire installs - low current) on the side where the controls are, but have wondered whether that ALL really needs to be armored or metal flex / mfc?

soot_seeker

Unknown

Wire

If you are referring to the wire coming out of the grey panel that the reset control is mounted on, that is SJO cord. There are three leads into the panel. One is incoming power for the system pump and DHW pump and the other two are for the power going out to those pumps. I made this control box. Inside are two DPDT relays, low voltage terminal strip, fuses, panel lights for Heat (Red) and DHW (Green) and Tekmar wiring enters box through door. All wiring has strain reliefs and clamps. Sensor and low voltage wiring all enters box through strain relief as well. I also incorporated toggle switches on the door to disable DHW Priority and Reset Control Functionality if neccessary. I travel a lot and if anything should happen to the DHW pump or Tekmar control, all my wife has to do is flip a switch and the heat will be back on. The Supply Sensor wiring is sleeven in EMT and wire penetrations into the immersion well are heat shrinked.


Glenn Stanton

Manager of Training

Burnham Hydronics

U.S. Boiler Co., Inc.

Unknown

The boiler temperature

will cool down during the off periods, but the lowest you will probably see it go would be about 100°F-110°F or so.

Glenn Stanton

Manager of Training

Burnham Hydronics

U.S. Boiler Co., Inc.

Unknown

The only issues

are that the code folks don't want the relief valve to share that nipple with anything anymore. This includes sensoers, makeup water, air vents, expansion tanks, supply takeoffs to indirect water heaters and anything else that people are tempted to pipe into the relief valve nipple. The exception would be a boiler manufacturer supplied tree such as the one we ship with the MPO or a similar device such as some of the Euro based companies use. These have dedicated tappings and an internal chamber of sorts.

Glenn Stanton

Manager of Training

Burnham Hydronics

U.S. Boiler Co., Inc.

Rodney Summers

more wire..

hi glenn,

i'll have to get a moment to take a picture of mine. you'll crack up a bit when you see it 'cause it looks almost the same as yours with the big grey elec box behind it in the same exact spot- it seemed the only logical way to mount it & contain the controls/wiring at the time.

so anyway, as far as you're concerned code-wise & what not, the SJ cord is ok to be used in that fashion at that location on the boiler? everybody always seems so intent on having bx or armored something for near boiler wiring; or at least if it's carrying line voltage/current to a load rather than to just a control. i can definitely understand that for the front area near the burner plate or top flue but have wondered if armored is absolutely required for line voltage-low current control wiring on the sides. any thoughts?

soot

Unknown

SJO Cord

Most of our Oil Boilers have burners configured with SJO Cord and 3 conductor plug to plug into a receptacle on the front of the boiler. Supporting the cord on longer lengths is probably the reason for the armored cable. The lengths I used are only about a foot long before they connect into a 4" square box and they are well away from any source of heat such as the flue pipe, cleanout plates and canopy. I could have made those connections with EMT as well but I wanted some flexibility in the event I ever needed to remove the right side jacket panel. All other wiring is in EMT other than the Factory wired Aquastat and LWCO. They are equipped with armored cable and molex plugs and snap right into to the junction box mounted under the jacket.

Glenn Stanton

Manager of Training

Burnham Hydronics

U.S. Boiler Co., Inc.

none_2

Control idea?

Hi Glenn,

Just wondering where you came up with the idea on the control?

tom_49

I like the tekmar on the outside. That way someones not stickin their hands where they DONT belong, near a bunch of live wires

grindog

bump

bump

TJ_4

stickin hands

The best way is to put the Tekmar inside. That way there is no temptation to play. If you use a good quality control manufacturer they will only need to hook up low voltage. The line voltage is normally covered by a raceway.
See our web site www.systemizerenclosures.com

We have the following controls pre-wired.
Tekmar 260 with DHW and three high temps.
Tekmar 256 with DHW and three high temps.
Tekmar 262 with DHW and three high temps.
Tekmar 360 with DHW and three high temps.
Tekmar 660 snow melt control with wiring for all pumps.

We also have patent pending on this product.

grindog

grey box

Glen what is the grey box on the side of your boiler? It looks really nice and seems to make wiring a snap. The other fellow posted another one just like it, can you purchase these some where or did you guys make them your selves makes the job look alot neater and those lites look neat to.

TJ_4

Purchase

Call 508-928-1136 to place an order or check out our web site. www.systemizerenclosures.com.

grindog

thanks for the info

thank you for the info, i checked out the site and everything looks great i would like to use these on one of my next projects . I am tired of the electricians screwing up the wiring on my boilers. Will call soon for pricing.

TJ_4

controls

Glenn, just wondering if you have a response on the control idea? Would you like to purchase one of our controls? We have several options available and can custom design them to fit any application.